Scientific American 1993-2013 Article Index

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Jan 2013
The Future in 50, 100, and 150 Years
We asked leading scientists and science writers to look forward to what the world will be like in the years 2063, 2113 and 2163 and tell us what role science and technology will play in our future.
Starship Humanity
How future generations will make the voyage from our earthly home to the planets and beyond—and what it means for our species
quantum physics
Strange and Stringy
Newly discovered states of matter embody what Einstein called “spooky action at a distance.” They defy explanation, but lately answers have come from a seemingly unrelated corner of physics: string theory
medical engineering
Bionic Connections
A new way to link artificial arms and hands to the nervous system could allow the brain to control prostheses as smoothly as if they were natural limbs
life science
Small Wonders
Light microscopy reveals hidden marvels of the natural world
The Coming Megafloods
Huge flows of vapor in the atmosphere, dubbed "atmospheric rivers," have unleashed massive floods every 200 years, and climate change could bring more of them
A Confederacy of Senses
Our many different senses collaborate even more than previously realized. What we hear depends a lot on what we see and feel
Dec 2012
World Changing Ideas
10 innovations that are radical enough to alter our lives
The Unquantum Quantum
Quantum theorists often speak of the world as being pointillist at the smallest scales. Yet a closer look at the laws of nature suggests that the physical world is actually continuous—more analog than digital
climate change
The Winters of Our Discontent
Loss of Arctic sea ice is stacking the deck in favor of harsh winter weather in the U.S. and Europe
medical ethics
Is Drug Research Trustworthy?
The pharmaceutical industry funnels money to prominent scientists who are doing research that affects its products—and nobody can stop it
Four Starry Nights
In the driest place on Earth, one astronomer sifts through starlight to find clues about the Milky Way's evolution. Here is her account of a typical trip, based on four days in March 2011
art conservation
The Case of the Disappearing Daguerreotypes
As priceless images from the earliest days of photography were dissolving in front of museumgoers' eyes, an unlikely team set out to save them
Mind Theorist
Knowledge of how the brain intuits what someone else is thinking helps Rebecca Saxe devise possible solutions to seemingly intractable political and social conflict
Nov 2012
particle physics
The Inner Life of Quarks
What if the smallest bits of matter actually harbor an undiscovered world of particles?
Grow Your Own Eye
Biologists have coaxed cells to form a retina, a step toward growing replacement organs outside the body
Global Warming: Faster Than Expected?
Loss of ice, melting of permafrost and other climate effects are occurring at an alarming pace
The Strangest Bird
Recent fossil discoveries reveal the surprising evolutionary history of penguins
science and society
America's Science Problem
The United States faced down authoritarian governments on the left and right. Now it may be facing an even greater challenge from within
Autism and the Technical Mind
Children of scientists and engineers may inherit genes that not only confer intellectual talents but also predispose them to autism
quantum physics
A New Enlightenment
Quantum theory once seemed like the last nail in the coffin of pure reason. Now it's looking like its savior
Oct 2012
State of The World's Science
A Measure of the Creativity of a Nation is how Well it Works with those Beyond its Borders
The Language of the Brain
The brain makes sense of our experiences by focusing closely on the timing of the impulses that flow through billions of nerve cells
Ecosystems on the Brink
To keep jellyfish, fungi and other creatures from overtaking healthy habitats, scientists are exploring food webs and tipping points
The Higgs at Last
After a three-decade search, scientists appear to have found the elusive particle. Its peculiar properties suggest a new era in physics could be about to dawn
Kinetic Kite
An airborne wind turbine turns sea breezes into electricity
The Wisdom of the Psychopaths
We can learn a lot from psychopaths. Certain aspects of their personalities and intellect are often hallmarks of success
Journey to the Genetic Interior
What was once known as junk DNA turns out to hold hidden treasures, says computational biologist Ewan Birney
Sep 2012
Beyond Limits How will we transcend today's barriers to get smarter, live longer, and expand the power of human innovation
Super Humanity
Our drive to exceed our evolutionary limits sets us apart from other beasts
Can We Keep Getting Smarter?
Ever rising IQ scores suggest that future generations will make us seem like dimwits in comparison
The Case of the Sleeping Slayer
In the neurological netherworld between sleep and wakefulness, the mind's delirium can turn tragically real
How We All Will Live to Be 100
Two approaches to longevity research aim to extend the average life span out to a century or more
Mind in Motion
The idea that paralyzed people might one day control their limbs just by thinking is no longer a Hollywood-style fantasy
The Edge of Ambition
10 projects that push the boundaries of the engineered world
Machines of the Infinite
Whether or not machines can quickly answer yes-or-no questions could affect everything from national security to the limits of human knowledge
basic science
Questions for the Next Million Years
What would scientists learn if they could run studies that lasted for hundreds or thousands of years—or more?
The Great Climate Experiment
How far can we push the planet?
Beyond the Quantum Horizon
Once viewed as imposing absolute limits on knowledge and technology, quantum theory is now expanding the power of computers and the vistas of the mind
Aug 2012
The Benevolence of Black Holes
The matter-eating beast at the center of the Milky Way may actually account for Earth's existence and habitability
The Joyful Mind
A new understanding of how the brain generates pleasure could lead to better treatment of addiction and depression—and even to a new science of happiness
evolutionary biology
New Life for Ancient DNA
Biotechnology reveals how the woolly mammoth survived the cold and other mysteries of extinct creatures
Lakes on Ice
Scientists are tracking how water atop Greenland's ice sheet pools and drains. The findings could help predict future rises in sea level
atomosphere science
Deadly Rays from Clouds
Thunderstorms give out powerful blasts of gamma rays and x-rays, shooting beams of particles—and even antimatter—into space. The atmosphere is a stranger place than we ever imagined
Building a Better Science Teacher
Experience and degrees don't matter in the classroom nearly so much as mastery of science and math and some plain old smarts
Quiet Little Traitors
Cells that permanently stop dividing have long been recognized as one of the body's defenses against cancer. Now they are also seen as a sometime culprit in cancer and a cause of aging
Which Species will Live?
Like battlefield medics, conservationists are being forced to explicitly apply triage to determine which creatures to save and which to let go
Phage Factor
Long ignored by mainstream researchers, the viruses that infect bacteria have a role to play in modern medicine, Vincent Fischetti says
Jul 2012
Why We Help
Far from being a nagging exception to the rule of evolution, cooperation has been one of its primary architects
Reading the Red Planet
At 10:31 p.m. Pacific time on August 5, NASA'S Curiosity rover will begin the first direct search for habitable environments on Mars
Secrets of the HIV Controllers
A rare group of HIV-positive individuals need no medicine to keep the virus in check. Their good fortune could point the way to more powerful treatments--and perhaps a vaccine
Fleet Foot
Nimble robots like this Cheetah will help the military navigate terrain too rocky for wheels
polar science
Witness to an Antarctic Meltdown
As glaciers collapse toward the sea, scientists struggle to figure out how fast the southern continent is melting and what that means for sea-level rise
Nobel Pursuits
The tools of science have changed since the golden age of physics, but many of the same questions remain
animal behavior
The Rat that Laughed
Do animals other than humans have a sense of humor? Maybe so
artificial intelligence
Machines that Think for Themselves
New techniques for teaching computers how to learn are beating the experts
Jun 2012
The Ultimate Social Network
Researchers who study the friendly bacteria that live inside all of us are starting to sort out who is in charge—microbes or people?
Super Supernovae
The largest stars die in explosions more powerful than anyone thought possible—some triggered in part by the production of antimatter
The Human Brain Project
Building a vast digital simulation of the brain could transform neuroscience and medicine and reveal new ways of making more powerful computers
Fusion's Missing Pieces
On the road to unlimited energy, the world's most complex science experiment encounters a few potholes
Busy Bee
Orchid pollinators are surprisingly promiscuous about the plants they like
infectious disease
Waiting to Explode
By concocting bird flu viruses that could potentially spread easily among humans, researchers have ignited a debate about the need for safety versus open inquiry
history of science
The Right Way to Get It Wrong
Most errors are quickly forgotten. Others end up remaking the face of science
Life is a Shell Game
Like people, hermit crabs and other animals trade up by treasuring what others leave behind
Resistance Fighter
Thumbi Ndung'u has moved from Africa to Massachusetts and back in a quest to halt the AIDS epidemic
May 2012
quantum physics
Loops, Trees and the Search for New Physics
Maybe unifying the forces of nature isn't quite as hard as physicists thought it would be
future health
Tomorrow's Medicine
A look at some of the most promising medical devices now in development
Triumph of the Titans
The long-necked dinosaurs known as sauropods, once seen as icons of extinction, thrived for millions of years all around the world
Erasing Painful Memories
The caustic imprint of a traumatic memory may fade or vanish with new drug and behavioral therapies
What a Plant Smells
Botanists are getting a whiff of the ways that plants smell one another. Some plants recognize injured neighbors by scent; others sniff out a meal
forensic medicine
Telltale Hearts
Despite advances in medical imaging, an autopsy still gives experts the best picture of what ails us
A Better Eye On the Storm
New technology that increases the warning time for tornadoes and hurricanes could potentially save hundreds of lives every year
Nature's Color Tricks
Understanding seven clever tactics animals use to create dazzling hues may lead to sophisticated new technologies
Professional Seer
The world's largest computer chipmaker employs a corporate futurist, Brian David Johnson, to guess what gadgetry and computing will look like in 2020 and beyond
Apr 2012
human evolution
First of Our Kind
Sensational fossils from South Africa spark debate over how we came to be human
Quantum Gravity in Flatland
Imagine space were 2-D rather than 3-D. How would the force of gravity work? The surprising answers are guiding physicists to a unified theory of nature
This Is Your Brain in Meltdown
Neural circuits responsible for conscious self-control are highly vulnerable to even mild stress. When they shut down, primal impulses go unchecked and mental paralysis sets in
space science
Bound for the Moon
The next rover to roam the moon's surface may come not from NASA and its rocket scientists but from college students and private companies working on a shoestring
Polio's Last Act
As the number of cases of the paralytic disease fall, world health officials have to grapple with a vexing problem: a component of the most widely used polio vaccine now causes more disease than the virus it is supposed to fight
Birth of a Cold War Vaccine
While the superpowers were busy threatening to destroy each other with nuclear weapons, Albert B. Sabin turned to a surprising ally to test his new oral polio vaccine—a Soviet scientist
Time Traveler
Artist Charles R. Knight drew on his vast experience depicting living animals to bring prehistoric creatures to life—a practice that made him keenly aware of the finality of extinction
The Limits of Breath Holding
It's logical to think that the brain's need for oxygen is what limits how long people can hold their breath. Logical, but not the whole story
Mar 2012
What Makes Each Brain Unique
How can identical twins grow up with different personalities? "Jumping genes" move around in neurons and alter the way they work
The Far, Far Future of Stars
Some say its glory days are long gone, but the universe has life in it yet. Brand-new types of celestial phenomena will unfold over the coming billions and trillions of years
Dinosaurs of the Lost Continent
The American West once harbored multiple communities of dinosaurs simultaneously—a revelation that has scientists scrambling to understand how the land could have supported so many behemoths
Gather the Wind
If renewable energy is going to take off, we need good ways of storing it for the times when the sun isn't shining and the wind isn't blowing
Blocking HIV's Attack
Scientists have rid one man of HIV by preventing the virus from entering certain immune cells. But the treatment was dangerous and likely unrepeatable. Can they figure out a safer, more broadly achievable way to help millions more?
info tech
The Shadow Web
Governments and corporations have more control over the Internet than ever. Now digital activists want to build an alternative network that can never be blocked, filtered or shut down
Lifting the Black Cloud
Existing antidepressants leave a lot to be desired. They can take weeks to start working, and they fail many people. Researchers are scouting for better options
Hit Them with the Hockey Stick
Michael E. Mann set out looking for a big scientific problem and wound up at the center of a political storm over climate change. Now he tells his side of the story
Feb 2012
Is Space Digital?
An experiment going up outside of Chicago will attempt to measure the intimate connections among information, matter and spacetime. If it works, it could rewrite the rules for 21st-century physics
The Great Prostate Cancer Debate
Evidence shows that screening does more harm than good. Now what?
Swept From Africa to the Amazon
What the journey of a handful of dust tells us about our fragile planet
public health
Sleeping With the Enemy
Bed bugs are back. Can science stop them?
citizen science
All Hands on Deck
Volunteers are combing through the logbooks of World War I-era ships to help researchers fill holes in the earth's climate record
sustainable agriculture
The Future of Chocolate
Researchers are racing to fortify the embattled cacao tree and to meet increasing demand for cocoa made from its seeds
brain science
The Collision Syndrome
Football players diagnosed with Lou Gehrig's disease may suffer from the effect of repeated blows to the head, controversial new research says
Fetal Armor
The placenta does more than nourish offspring in the womb—it actively shapes brain development
The Brittle Star's Apprentice
Chemist Joanna Aizenberg mines the deep sea and the forest wetlands for nature's design secrets and uses them to fashion new materials that may change the world
Jan 2012
A New Path to Longevity
Researchers have uncovered an ancient mechanism that retards aging. Drugs that tweaked it could well postpone cancer, diabetes and other diseases of old age
Goldilocks Black Holes
Tipping the scales at less than about a million suns in mass, middleweight black holes may hold clues to how their much larger siblings, and galaxies, first formed
animal behavior
The Compass Within
Animals' magnetic sense is real. Scientists are zeroing in on how it works
The Patient Scientist
When Ralph M. Steinman developed pancreatic cancer, he put his own theories about cancer and the immune system to the test. They kept him alive longer than expected--but three days short of learning he had won the Nobel Prize
Five Hidden Dangers of Obesity
Excess weight can harm health in ways that may come as a surprise
The Department of Pre-Crime
In cities across the U.S. data-rich computer technology is telling cops where crimes are about to happen. Crime is down, and the technology is spreading. But does it really work?
The Science of the Glory
One of the most beautiful phenomena in meteorology has a surprisingly subtle explanation. Its study also helps to predict the role that clouds will play in climate change
More Food, Less Energy
Changes in agriculture, policy and personal behaviors can reduce the energy a nation uses to feed itself and the greenhouse gases it emits
Dust Up
Biologist Jayne Belnap warns of the consequences for the American West if we don't preserve a home for the minute organisms that live in desert topsoil
Dec 2011
World Changing Ideas
10 new technologies that will make a difference
The Machine That Would Predict the Future
If you dropped all the world's data into a black box, could it become a crystal ball that would let you see the future—even test what would happen if you chose A over B? One researcher thinks so, and he could soon get a billion euros to build it
space exploration
This Way to Mars
By adapting ideas from robotic planetary exploration, the human space program could get astronauts to asteroids and Mars cheaply and quickly
Dazzling Miniatures
Small worlds writ large under the microscope
climate change
After the Deluge
A spate of floods, droughts and heat waves is prompting city and state leaders to take bold steps to protect their people and property
Hidden Switches in the Mind
Experience may contribute to mental illness in a surprising way: by causing "epigenetic" changes—ones that turn genes on or off without altering the genes themselves
animal behavior
Ants & the Art of War
Battles among ants can be startlingly similar to human military operations
Arm in the Ice
New fingerprint- and DNA-identification techniques solve a mystery from a 60-year-old plane crash
Speaking Out on the "Quiet Crisis"
Strengthening science education is the key to securing our energy future, says Rensselaer Polytechnic Institute's president
Nov 2011
The 1st Americans
Humans colonized the New World earlier than previously thought—a revelation that is forcing scientists to rethink long-standing ideas about these trailblazers
planetary science
Digging Mars
The Mars Phoenix mission revived hopes that the Red Planet may be habitable, preparing the way for a new rover to be launched this month
planetary science
The Smallest Astronauts
Did space rocks seed Earth with life? To test that idea, a Russian probe is about to see whether microbes can survive a round-trip to Mars
experimental philosophy
Thought Experiments
Some philosophers today are doing more than thinking deeply. They are also conducting scientific experiments relating to the nature of free will and of good and evil
Can We Feed the World & Sustain the Planet?
A five-step global plan could double food production by 2050 while greatly reducing environmental damage
Sleeping Giant
The volcano beneath this calm-looking lake has grown restive, inspiring a rare collaboration between Chinese and Korean scientists
The Wipeout Gene
A new breed of genetically modified mosquitoes carries a gene that cripples its own offspring. They could crush native mosquito populations and block the spread of disease. And they are already in the air—though that's been a secret
A Formula for Economic Calamity
Despite the lessons of the 2008 collapse, Wall Street is betting our future on flimsy science
The Truth About Fracking
Fracturing a deep shale layer one time to release natural gas might pose little risk to drinking-water supplies, but doing so repeatedly could be problematic
The Medical Sleuth
As a disease detective at the NIH, William A. Gahl unravels the cause of illnesses that have stumped other doctors
Oct 2011
The Dark Side of The Milky Way
Dark matter is not just a puzzle. It is a solution
Atom Power
2011 is the International Year of Chemistry—a well-deserved celebration of that science's profound power
10 Unsolved Mysteries
Many of the most profound scientific questions—and some of humanity's most urgent problems—pertain to the science of atoms and molecules
The Scent of Your Thoughts
Although we are usually unaware of it, we communicate through chemical signals just as much as birds and bees do
Afghanistan's Buried Riches
Geologists say newfound deposits in the embattled country could fulfill the world's desire for rare-earth and critical minerals and end opium's local stranglehold in the process
A New Ally against Cancer
The FDA recently okayed the first therapeutic cancer vaccine, and other drugs that enlist the immune system against tumors are under study
How Skulls Speak
New 3-D software is helping scientists identify the sex and ancestral origins of human remains with greater speed and precision
Waiting for the Higgs
Even as the last protons spin through the most successful particle accelerator in history, physicists hope to conjure one final triumph
The Dinosaur Baron of Transylvania
A maverick aristocrat's ideas about dinosaur evolution turn out to have been decades ahead of their time
Actuary of the Cell
Building on her Nobel Prize-winning research on cell function, Elizabeth H. Blackburn is trying to find a simple measure of a person's health risks
Sep 2011
Street-Savvy Meeting the biggest challenges starts with the city
The Social Nexus The best way to harness a city's potential for creativity and innovation is to jack people into the network and get out of the way
Engines of Innovation Most of humanity now lives in a metropolis. That simple fact helps to fuel our continued success as a species
Global Bazaar Shantytowns, favelas and jhopadpattis turn out to be places of surprising innovation
Brains Over Buildings To rejuvenate urban centers, look to teachers and entrepreneurs
How Green Is My City Retrofitting is the best way to clean up urban living
All Climate Is Local Mayors are often better equipped than presidents to cut greenhouse gases
The Efficient City Municipalities worldwide are exploiting a host of creative solutions to reduce energy consumption, water use, waste and emissions, while also making it easier for people to get around
Castles in the Air The attacks of 9/11 supposedly ended the age of the skyscraper. A decade on we're building more than ever
Street Talk What innovation -- technological or otherwise -- would make any city a substantially more livable place? We put this question to urban leaders and our own readers. Here's what they said
Life in the Meta City We walk a line between the anarchy of choice and Disney-fication, says the author of Neuromancer
Aug 2011
Does the Multiverse Really Exist?
Proof of parallel universes radically different from our own may still lie beyond the domain of science
human origins
The Evolution of Grandparents
Senior citizens may have been the secret of our species' success
How To Build a Better Learner
Brain studies suggest new ways to improve reading, writing and arithmetic—and even social skills
The False Promise of Biofuels
The breakthroughs needed to replace oil with plant-based fuels are proving difficult to achieve
life science
Treasure in the Trees
Nests offer clues about natural history, climate change and their owners' mating habits
A Breath of Fresh Air
Fundamental understanding of basic biology has set the stage for new treatments for cystic fibrosis
How New York Beat Crime
With its judicious use of cops and innovative methods, the Big Apple is a model for how to stem homicides, muggings and other ills
philosophy of science
Why Math Works
Is math invented or discovered? A leading astrophysicist suggests that the answer to the millennia-old question is both
Zahi Hawass, Egypt's Indiana Jones and One-Time Mubarak Ally, Tries to Cozy Up to Pro-Democracy Activists
Egypt had a revolution, but Zahi Hawass, the larger-than-life minister of antiquities, is still calling his own shots and making no apologies
Jul 2011
The Limits of Intelligence
The laws of physics may well prevent the human brain from evolving into an ever more powerful thinking machine
The Periodic Table of the Cosmos
A simple diagram, which celebrates its centennial this year, continues to serve as the most essential conceptual tool in stellar astrophysics
health care
The Best Medicine
A quiet revolution in comparative effectiveness research just might save us from soaring medical costs
climate change
The Last Great Global Warming
Surprising new evidence suggests the pace of the earth's most abrupt prehistoric warm-up paled in comparison to what we face today. The episode has lessons for our future
Underground Railroad
A peek inside New York City's subway line of the future
Evolution of the Eye
Scientists now have a clear vision of how our notoriously complex eye came to be
Hacking the Lights Out
Computer viruses have taken out hardened industrial control systems. The electrical power grid may be next
disease control
Scent of a Human
Decoding how a mosquito sniffs out human targets could lead to better traps and repellents that cut malaria's spread
Bad Boy of Physics
Leonard Susskind rebelled as a teen and never stopped. Today he insists that reality may forever be beyond reach of our understanding
Jun 2011
Living In A Quantum World
Quantum mechanics is not just about teeny particles. It applies to things of all sizes: birds, plants, maybe even people
A Test for Consciousness
How will we know when we've built a sentient computer? By making it solve a simple puzzle
nuclear energy
Planning for the Black Swan
The surprising accident at Fukushima puts the spotlight on a new generation of U.S. nuclear reactors. Are they safe enough?
A Nobel Celebration
As Nobel Prize winners gather this month to share their wisdom with younger researchers, Scientific American recalls some of the articles that Nobel laureates have published in our pages
Inside the Meat Lab
A handful of scientists aim to satisfy the world's growing appetite for steak without wrecking the planet. The first step: grab a petri dish
The Smartest Bacteria on Earth
One species of soil microbe makes unusually wise communal decisions
The Devil's Cancer
A contagious tumor threatens to wipe out the famous Tasmanian devil. Could similarly "catching" cancers arise in humans, too?
history of science
Greater Glory
In the race to the South Pole, explorer Robert F. Scott refused to sacrifice his ambitious science agenda
global warming
"I Stick to Science"
Why Richard A. Muller wouldn't tell House climate skeptics what they wanted to hear
May 2011
7 Radical Energy Solutions
The failure rate may be 90 percent, but if any of these exotic technologies succeeds it could significantly improve energy security and efficiency
The Lost Galaxies
By the latest estimate, the observable universe contains 200 billion galaxies. Astronomers wonder: Why so few?
The Hidden Organ In Our Eyes
Our bodies adjust to the cycle of day and night thanks to specialized neurons in our eyes. Ongoing study of these cells could lead to new treatments for winter depression and other conditions
The Strangest Numbers in String Theory
A forgotten number system invented in the 19th century may provide the simplest explanation for why our universe could have 10 dimensions
Fast Track to Vaccines
Analyzing all the layers of the immune system at once speeds design and may one day deal a decisive blow against HIV
The Space Station's Crown Jewel
A fancy cosmic-ray detector, the Alpha Magnetic Spectrometer, is about to scan the cosmos for dark matter, antimatter and more
The Growing Menace from Superweeds
Pigweed, ragweed and other monsters have begun to outsmart the advanced technologies that protect the biggest U.S. cash crops
natural history
Masters of Disguise
Animal mimicry takes many forms—including chemical and acoustic varieties—and offers unique insights into evolution
Inner Sparks
Hearing specialist and sax player Charles J. Limb says that studying the brain during flights of improvisation may provide new understanding of creativity—as well as insight into the musical genius of John Coltrane
Apr 2011
The Inflation Debate
Is the theory at the heart of modern cosmology deeply flawed?
The Enemy Within
A new pattern of antibiotic resistance that is spreading around the globe may soon leave us defenseless against a frighteningly wide range of dangerous bacterial infections
Neuroscience in the Courtroom
Brain scans and other types of neurological evidence are rarely a factor in trials today. Someday, however, they could transform judicial views of personal credibility and responsibility
Can the Dead Sea Live?
Irrigation and mining are sucking the salt lake dry, but together Israel, Jordan and the Palestinian Authority could save the sacred sea
artificial intelligence
Solving the Cocktail Party Problem
Computers have great trouble deciphering voices that are speaking simultaneously. That may soon change
cell biology
The Orderly Chaos of Proteins
To do their magic in the cell, proteins must fold into rigid shapes—or so standard wisdom says. But a more tangled story is beginning to emerge
Seconds Before the Big One
Earthquake detection systems can sound the alarm in the moments before a big tremor strikes—time enough to save lives
Food Fight
Genetically modified crops, says agro-research czar Roger Beachy, receive an unjustified shellacking from environmentalists
animal behavior
Natural-Born Killer
Lethal from day one, the tentacled snake uses surprisingly sly tactics to capture fish
Mar 2011
The Neuroscience of True Grit
When tragedy strikes, most of us ultimately rebound surprisingly well. Where does such resilience come from?
space science
Journey to the Innermost Planet
Mercury has never been orbited by a spacecraft before. That will change this month
Diseases in a Dish
A creative use of stem cells made from adult tissues may hasten drug development for debilitating diseases
Signals in a Storm
A new computer imaging technique shows researchers how brain cells communicate—one molecule at a time
Putting Stonehenge in Its Place
An increasingly accepted view holds that the great stone circle may have been just part of a much larger ceremonial landscape
Demons and the Quest Entropy for Absolute Zero
A 19th-century thought experiment has turned into a real technique for reaching ultralow temperatures, paving the way to new scientific discoveries as well as to useful applications
climate change
A Shifting Band of Rain
By mapping equatorial rainfall since A.D. 800, scientists have figured out how tropical weather may change through 2100
public health
Not Just an Illness of the Rich
Recent global health campaigns have focused on HIV, tuberculosis and malaria. Tackling the growing threat from cancer, says medical anthropologist Paul Farmer, could improve health care more broadly
Dinosaur Death Trap
On a trip to the Gobi Desert, a team of fossil hunters unearths a death scene that reveals new clues about how dinosaurs lived
Feb 2011
How to Fix the Obesity Crisis
Although science has revealed a lot about metabolic processes that influence our weight, the key to success may lie elsewhere
Citizen Satellites
Tiny, standardized spacecraft are making orbital experiments affordable to even the smallest research groups
The Blue Food Revolution
New fish farms out at sea, and cleaner operations along the shore, could provide the world with a rich supply of much needed protein
cognitive psychology
How Language Shapes Thought
The languages we speak affect our perceptions of the world
The Inner Life of the Genome
The way our genes are arrayed and move in the 3-D space of the cell nucleus turns out to profoundly influence how they function, in both health and disease
A Friend to Aliens
Buckthorn, garlic mustard and many other invasive species do not pose as big a threat as some scientists think, says ecologist Mark Davis
X-Ray Vision
Thanks to amazing nested mirrors, NASA's NuSTAR telescope is set to reveal hidden phenomena in the cosmos
Mind Out of Body
In an exclusive excerpt from his new book, a pioneering neuroscientist argues that brain-wave control of machines will allow the paralyzed to walk and portends a future of mind melds and thought downloads
history of science
Jefferson's Moose
Thomas Jefferson waged a second revolution, fighting the image created by European naturalists of a degenerate America
Jan 2011
Dawn of the Deed
Fish fossils push back the origin of copulation in backboned animals and suggest that it was a key turning point in our evolution
Contact The Day After
If we are ever going to pick up a signal from E.T., it is going to happen soon, astronomers say. And we already have a good idea how events will play out
infectious disease
Flu Factories
The next pandemic virus may be circulating on U.S. pig farms, but health officials are struggling to see past the front gate
In Search of the Radical Solution
The greatest energy payoffs, says investor Vinod Khosla, will come from fundamentally reinventing mainstream technologies
Seeds of the Amazon
Botanists have collected seeds from one of the most biologically diverse places on earth
100 Trillion Connections
The noise of billions of brain cells trying to communicate with one another may hold a crucial clue to understanding consciousness
Casualties of Climate Change
Shifts in rainfall patterns and shorelines will contribute to mass migrations on a scale never before seen
computer science
Rise of the Robo Scientists
Machines can devise a hypothesis, carry out experiments to test it and assess results—without human intervention
public health
Radioactive Smoke
The tobacco industry has known for decades how to remove a dangerous isotope from cigarettes but has done nothing about it. The government now has the power to force a change
Dec 2010
World Changing Ideas
Ten thoughts, trends and technologies that have the power to transform our lives
A Geometric Theory of Everything
Deep down, the particles and forces of the universe are a manifestation of exquisite geometry
Blood from Stone
Mounting evidence from dinosaur bones shows that, contrary to common belief, organic materials can sometimes survive in fossils for millions of years
Life Unseen
Microscopic landscapes show a surprising diversity of forms
Hallucinogens as Medicine
In a matter of hours, mind-altering substances may induce profound psychological realignments that can take decades to achieve on a therapist's couch
info science
Long Live the Web
The Web is critical not merely to the digital revolution but to our continued prosperity—and even our liberty. Like democracy itself, it needs defending
life science
Jane of the Jungle
Primatologist Jane Goodall shares insights from her 50 years among chimpanzees
space exploration
Jump-Starting the Orbital Economy
Why NASA's plan to get out of the manned spaceflight business may (finally) make space travel routine
Cyborg Beetles
Tiny flying robots that are part machine and part insect may one day save lives in wars and disasters
Nov 2010
Dark Worlds
A shadow cosmos, woven silently into our own, may have its own rich inner life
Controlling the Brain with Light
With a technique called optogenetics, researchers can probe how the nervous system works in unprecedented detail. Their findings could lead to better treatments for psychiatric problems
How to Build the Supergrid
The U.S. needs a new electric transmission system to deliver cleaner, more reliable power nationwide. Four steps could clear hurdles
Phosphorus Lake
Strip-mining Florida to fertilize the nation
Dr. Unification
For years the cosmos and the atom have been at odds with one another. If any physicist can reconcile them, it's Steven Weinberg
Halting the World's Most Lethal Parasite
A new malaria vaccine, a plan to immunize mosquitoes and other "crazy" ideas have brightened prospects for vanquishing this killer
From Silk Cocoon to Medical Miracle
Scientists are crafting arteries, ligaments, circuitry and holograms from worm yarn
Climate Heretic
Why can't we have a civil conversation about climate?
Oct 2010
How We Are Evolving
New analyses suggest that recent human evolution has followed a different course than biologists would have expected
Origami Observatory
NASA is building an innovative and risky space telescope that promises to surpass the hugely successful Hubble. Here's an exclusive, behind-the-scenes look at the most audacious space project in decades
In Science We Trust
Our Web survey of readers suggests that the scientifically literate public still trusts its experts—with some important caveats
Revolution Postponed
The Human Genome Project has failed so far to produce the medical miracles that scientists promised. Biologists are now divided over what, if anything, went wrong—and what needs to happen next
The (Elusive) Theory of Everything
Physicists have long sought to find one final theory that would unify all of physics. Instead they may have to settle for several
Robot Be Good
Autonomous machines will soon play a big role in our lives. It's time they learned how to behave ethically
Sensational Sucker
The octopus sucker can feel, taste, grip, manipulate—and act of its own accord
Desperate for an Autism Cure
Diagnoses have soared, but valid treatments are few. Parents have turned instead to dubious, and often risky, alternative therapies
Reinventing the Leaf
The ultimate fuel may come not from corn or algae but directly from the sun itself
info science
Digitizer in Chief
The first step toward transparent government, says White House information czar Vivek Kundra, is to make all its information freely available on the Web
Sep 2010
Eternal Fascinations with the End Why we're suckers for stories of our own demise
Why Can't We Live Forever
As we grow old, our own cells begin to betray us. By unraveling the mysteries of aging, scientists may be able to make our lives longer and healthier
When Does Life Belong to the Living?
With thousands of people on the waiting lists for organs, doctors are bending the rules about when to declare that a donor is dead. Is it ethical to take one life and give it to another?
Dust to Dust
The brief, eventful afterlife of a human corpse
Last of Their Kind
The world's cultures have been disappearing, taking valuable knowledge with them, but there is reason to hope
Good Riddance
A highly selective list of human creations the world would be better off without
How Much is Left?
A graphical accounting of the limits to what one planet can provide
risk analysis
Laying Odds on the Apocalypse
Could modern civilization really come to an end? Experts take stock of eight doomsday scenarios
Could Time End?
Yes. And no. For time to end seems both impossible and inevitable. Recent work in physics suggests a resolution to the paradox
What Comes Next
The flip side to every ending is a new beginning. We asked the visionary scientists on our advisory board what new trends will shape the decades to come
Aug 2010
Planets We Could Call Home
The night skies are littered with distant planets, but what are they really like? Theoretical models suggest that a surprising number of "exoplanets" could be similar to Earth—and may even support life
Sometimes we forget where a story really starts. Are electric cars new? Were did malaria start? Who invented spaghetti? Read on, for the surprising origins of many strange and familiar things.
When the Sea Saved Humanity
Shortly after Homo sapiens arose, harsh climate conditions nearly extinguished our species. Recent finds suggest that the small population that gave rise to all humans alive today survived by exploiting a unique combination of resources along the southern coast of Africa
Robot Pills
A voyage through the human body is no longer mere fantasy. Tiny devices may soon perform surgery, administer drugs and help diagnose disease
Threatening Ocean Life from the Inside Out
Carbon dioxide emissions are making the oceans more acidic, imperiling the growth and reproduction of species from plankton to squid
Filming the Invisible in 4D
Picture this: a movie revealing the inner workings of a cell or showing a nanomachine in action. A new microscopy is making such imaging possible
The Hacker in Your Hardware
As if software viruses weren't bad enough, the microchips that power every aspect of our digital world are vulnerable to tampering in the factory. The consequences could be dire
Plastic Surf
Small remnants of toys, bottles and packaging have an unhealthful afterlife in the ocean
Jul 2010
Is The Universe Leaking Energy?
Total energy must be conserved. Every student of physics learns this fundamental law. The trouble is, it does not apply to the universe as a whole
DNA Drugs Come of Age
After years of false starts, a new generation of DNA vaccines and medicines for HIV, influenza and other stubborn illnesses is now in clinical trials
The Dirty Truth About Plug-In Hybrids
How green is that electric car? Depends on where you plug it in
War of the Machines
Robots on and above the battlefield are bringing about the most profound transformation of warfare since the advent of the atom bomb
Clean Energy From Filthy Water
California cities are pumping their treated wastewater underground to create electricity
Winged Victory
Modern birds, long thought to have arisen only after the dinosaurs perished, turn out to have lived alongside them
How Babies Think
Even the youngest children know, experience and learn far more than scientists ever thought possible
The Drillers Are Coming
Companies and regulators are squaring off over a controversial technique that yields natural gas but threatens to pollute water supplies
Jun 2010
12 Events That Will Change Everything
Several events, both natural and man-made, can happen suddenly and at any time, completely transforming societies. Many of these events will not unfold the way popular conceptions have imagined they will.
Alzheimer's - Forestalling the Darkness
Interventions before symptoms appear could be key to slowing or stopping the leading cause of dementia
Is Time An Illusion?
The concepts of time and change may emerge from a universe that, at root, is utterly static
Washing Carbon Out of the Air
Machines could absorb carbon dioxide from the atmosphere, slowing or even reversing its rise and reducing global warming
Did Neandertals Think Like Us?
João Zilhão defends his controversial view that our oft-maligned relatives shared our cognitive abilities
earth science
The Earth's Missing Ingredient
The discovery of a novel high-density mineral means that the earth's mantle is a more restless place than scientists suspected—and offers new clues to the planet's history
Fake Botox, Real Threat
A booming market for a counterfeit beauty product could put a deadly biological weapons agent in the wrong hands
May 2010
Through Neutrino Eyes
Neutrinos are no longer just a curiosity of physics but a practical tool for astronomy
Your Inner Healers
Reprogramming cells from your own body could give them the therapeutic power of embryonic stem cells, without the political controversy
Revolutionary Rail
High-speed trains are coming to the U.S.
Uncanny Sight in the Blind
Some people who are blind because of brain damage have "blindsight": an extraordinary ability to react to emotions on faces and even navigate around obstacles without knowing they can see anything
climate change
Arctic Plants Feel the Heat
Global warming is dramatically revamping not only the ice but also tundra and forests at the top of the world, greening some parts and browning others. The alterations could exacerbate climate change
A Better Lens on Disease
Computerized pathology slides may help doctors make faster and more accurate diagnoses
food science
Breeding Cassava to Feed the Poor
The world's third-largest source of calories has the potential to become a more productive and more nutritious crop, alleviating malnutrition in much of the developing world
Apr 2010
8 Wonders of the Solar System
Artist Ron Miller takes us on a journey to eight of the most breathtaking views that await intrepid explorers of our solar system. The scale of these natural wonders dwarfs anything Earth has to offer. What might we see and feel if we could travel to these distant domains? The artist's eye—interpreting data from probes such as NASA's Cassini, which is now exploring the Saturnian system, and MESSENGER, which has flown by Mercury three times and goes into permanent orbit next March—allows us an early visit to these unforgettable locales.
Faulty Circuits
Neuroscience is revealing the malfunctioning connections underlying psychological disorders and forcing psychiatrists to rethink the causes of mental illness
Boundaries for a Healthy Planet
Humankind has fundamentally altered the planet. But new thinking and new actions can prevent us from destroying ourselves. Scientists have set thresholds for key environmental processes that, if crossed, could threaten Earth's habitability
Solutions to Environmental Threats
Ominously, three thresholds for key environmental processes have already been exceeded. Experts tell Scientific American which actions will keep key processes in bounds
Breaking the Growth Habit
Society can safeguard its future only by switching from reckless economic growth to smart maintenance of wealth and resources
Regaining Balance with Bionic Ears
Electronic implants in the inner ear may one day restore clear vision and equilibrium in some patients who experience disabling unsteadiness
The Rise of Instant Wireless Networks
Wireless networks that do not depend on a fixed infrastructure will allow for ubiquitous connectivity regardless of the situation
The Hidden Life of Truffles
Not just for gourmands, truffles play essential roles in the health of ecosystems
Mar 2010
planetary science
The Moon That Would Be A Planet
Titan, Saturn's largest natural satellite, scarcely deserves to be a called a mere moon. It has an atmosphere thicker than Earth's and a surface that is almost as varied
The Brain's Dark Energy
Brain regions active when our minds wander may hold a key to understanding neurological disorders and even consciousness itself
Fusion's False Dawn
Scientists have long dreamed of harnessing nuclear fusion—the power plant of the stars—for a safe, clean and virtually unlimited energy supply. Even as a historic milestone nears, skeptics question whether a working reactor will ever be possible
Evolution of Minerals
Looking at the mineral kingdom through the lens of deep time leads to a startling conclusion: most mineral species owe their existence to life
Toxic Gas, Lifesaver
Hydrogen sulfide, a lethal gas best known for smelling like rotten eggs, turns out to play key roles in the body—a finding that could lead to new treatments for heart attack victims and others
animal behavior
Worm Charmers
As Charles Darwin had suspected, earthworms that flee from ground vibrations do so to escape hungry moles—even though sometimes it is humans chasing them
Climate Change: A Controlled Experiment
Scientists have carefully manipulated grasslands and forests to see how precipitation, carbon dioxide and temperature changes affect the biosphere, allowing them to forecast the future
Feb 2010
Cloudy with a Chance of Stars
Making a star is no easy thing
The Naked Truth
Recent findings lay bare the origins of human hairlessness—and hint that naked skin was a key factor in the emergence of other human traits
Better Mileage Now
Emerging technologies could make the internal-combustion engine substantially more fuel-efficient, even as green vehicles make inroads
The Art of Bacterial Warfare
New research reveals how bacteria hijack our body's cells and outwit our immune system—and how we can use their own weapons against them
Fixing the Global Nitrogen Problem
Humanity depends on nitrogen to fertilize croplands, but growing global use is damaging the environment and threatening human health. How can we chart a more sustainable path?
Seeing Forbidden Colors
People can be made to see reddish green and yellowish blue—colors forbidden by theories of color perception. These and other hallucinations provide a window into the phenomenon of visual opponency
life science
The Prolific Afterlife of Whales
On the deep seafloor, the carcasses of the largest mammals give life to unique ecosystems
Ask the Experts Can people ever lose their fingerprints?
Jan 2010
Looking for Life in the Multiverse
Universes with different physical laws might still be habitable
The Rise and Fall of Nanobacteria
Once believed to be the smallest pathogens known, nanobacteria have now proved to be something almost as strange. They do play a role in health—just not the one originally thought
earth science
Violent Origins of Continents
Did asteroid strikes during the earth's youth spawn the earliest fragments of today's landmasses?
info tech
Real Money from Virtual Worlds
Online fantasy games enable developing world entrepreneurs to make a living by trading stashes of make-believe gold for hard cash
Local Nuclear War, Global Suffering
Worry has focused on the U.S. versus Russia, but a regional nuclear war between India and Pakistan could blot out the sun, starving much of the human race
The Next 20 Years of Microchips
Designers are pushing all the boundaries to make integrated circuits smaller, faster and cheaper
A Plan to Defeat Neglected Tropical Diseases
The poorest people are not only poor. They are also chronically sick, making it harder for them to escape poverty. A new global initiative may break the vicious cycle
Dec 2009
Portrait of a Black Hole
By adapting a global network of telescopes, astronomers will soon get their first look ever at the dark silhouette of a black hole
World Changing Ideas
20 ways to build a cleaner, healthier, smarter world
origin of life
Expanding the Limits of Life
Analyses of a recently discovered type of hot vent ecosystem in the seafloor suggest new possibilities for how life evolved
Methane: A Menace Surfaces
Arctic permafrost is already thawing, creating lakes that emit methane. The heat-trapping gas could dramatically accelerate global warming. How big is the threat? What can be done?
Decoding an Ancient Computer
New explorations have revealed how the antikythera mechanism modeled lunar motion and predicted eclipses, among other sophisticated tricks
The Double Life of ATP
The molecule ATP, famous as an essential energy source inside cells, also carries critical messages between cells. That dual role is suggesting fresh ideas for fighting human diseases
Illuminating the Lilliputian
A gallery of images captured by light microscopy reveals the high art of the natural world
Ask the Experts Why did NASA decide to launch space shuttles from weather-beaten Florida?
Nov 2009
The Long Lost Siblings of the Sun
The sun was born in a family of stars. What became of them?
New Culprits in Chronic Pain
Glia are nervous system caretakers whose nurturing can go too far. Taming them holds promise for alleviating pain that current medications cannot ease
A Path to Sustainable Energy by 2030
Wind, water and solar technologies can provide 100 percent of the world's energy, eliminating all fossil fuels. Here's how
human evolution
Rethinking the Hobbits of Indonesia
New analyses reveal the mini human species to be even stranger than previously thought and hint that major tenets of human evolution need revision
info tech
The Everything TV
Modern insights into the immune system have revived interest in adding ingredients that can supercharge old vaccines and make entirely new ones possible
The Rise of Vertical Farms
Growing crops in city skyscrapers would use less water and fossil fuel than outdoor farming, eliminate agricultural runoff and provide fresh food
auto tech
The Future of Cars
Industry Leaders Look Way Down the Road
Ask the Expert How Does the Coast Guard Find People Lost at Sea?
Oct 2009
Black Stars, Not Holes
Quantum effects may prevent true black holes from forming and give rise instead to dense entities called black stars
Turbocharging the Brain
Will a pill at breakfast improve concentration and memory—and will it do so without long-term detriment to your health?
Squeezing More Oil from the Ground
Amid warnings of a possible "peak oil," advanced technologies offer ways to extract every last possible drop
Lost Cities of the Amazon
The Amazon tropical forest is not as wild as it looks
Boosting Vaccine Power
Modern insights into the immune system have revived interest in adding ingredients that can supercharge old vaccines and make entirely new ones possible
Privacy and the Quantum Internet
Courtesy of some of the weirdest laws of physics, we may someday be able to search and surf the Web without anyone collecting our data
Biotech's Plans to Sustain Agriculture
Popular movements may call for more organic methods, but the agricultural industry sees biotechnology as a crucial part of farming's future
Ask the Experts Why do whales beach themselves
Sep 2009
Origin of the Universe
Cosmologists are closing in on the ultimate processes that created and shaped the universe
Origin of the Mind
The first step in figuring out how the human mind arose is determining what distinguishes our mental processes from those of other creatures
Origin of Life on Earth
Fresh clues hint at how the first living organisms arose from inanimate matter
info tech
Origin of Computing
The information age began with the realization that machines could emulate the power of minds
innovations, history
Origins - The Start of Everything
Where do rainbows come from? What about flying cars, love and LSD?
Aug 2009
human evolution
Twilight of the Neandertals
Paleoanthropologists know more about Neandertals than any other extinct human. But their demise remains a mystery, one that gets curiouser and curiouser
Adventures in Curved Spacetime
The possibility of "swimming" and "gliding" in curved, empty space shows that, even after nine decades, Einstein's theory of general relativity continues to amaze
energy policy
What Now for Nuclear Waste?
Yucca Mountain was supposed to be the answer to the U.S.'s nuclear waste problem, but after 22 years and $9 billion, that vision is dead. Now some say that doing nothing in the near term may be the smartest solution
Surprises from Celiac Disease
Study of a potentially fatal food-triggered disease has uncovered a process that may contribute to many autoimmune disorders
An Iron Key to High-Temperature Superconductivity?
The discovery that compounds known as iron pnictides can superconduct at 50 degrees above absolute zero has reignited physicists' quest for better high-temperature superconductors and may offer clues to unlocking a 20-year mystery
innovations, medicine
A New Kind of Drug Target
An emerging class of medicines works its magic by targeting unusual sites on biological molecules
Ask the Experts How does bathwater well below the boiling point give off steam?
Jul 2009
space exploration
From the Moon to Mars
The only scientist and field geologist ever to visit the moon offers some pointers to those who will one day visit Mars
New Ways to Squash Superbugs
Scientists are using new tools and tactics in the race to discover novel antibiotics
Grassoline at the Pump
Scientists are turning agricultural leftovers, wood and fast-growing grasses into a huge variety of biofuels—even jet fuel. But before these next-generation biofuels go mainstream, they have to compete with oil at $60 a barrel
Origins of the Left & Right Brain
The division of labor by the two cerebral hemispheres—once thought to be uniquely human—predates us by half a billion years. Speech, right-handedness, facial recognition and the processing of spatial relations can be traced to brain asymmetries in early vertebrates
The Ivory Trail
The illegal slaughter of African elephants for ivory is now worse than it was at its peak in the 1980s. New forensic tools based on DNA analysis can help stop the cartels behind this bloody trade
The Science of Bubbles & Busts
The worst economic crisis since the Great Depression has prompted a reassessment of how financial markets work and how people make decisions about money
Ask the Experts Why haven't humans evolved eyes in the back of the head?; Instead of sequestering carbon dioxide to reduce its effects on global climate, why don't we split it into harmless carbon and oxygen?
Jun 2009
Improbable Planets
Astronomers are finding planets where there were not supposed to be any
The Price of Silent Mutations
Small changes to DNA that were once considered innocuous enough to be ignored are proving to be important in human diseases, evolution and biotechnology
Phosphorus: A Looming Crisis
This underappreciated resource—a key part of fertilizers—is still decades from running out. But we must act now to conserve it, or future agriculture will collapse
tech leaders
Scientific American 10
Certain researchers, politicians, business executives and philanthropists have recently demonstrated outstanding commitment to making sure that the benefits of new technologies and knowledge will accrue to humanity
The Taming of the Cat
Genetic and archaeological findings hint that wildcats became house cats earlier--and in a different place--than previously thought
info tech
Data in the Fast Lanes of Racetrack Memory
A device that slides magnetic bits back and forth along nanowire "racetracks" could pack data in a three-dimensional microchip and may replace nearly all forms of conventional data storage
Ask the Experts What causes albinism? Are there any treatments for it?; Why do two things I like to eat sometimes taste so bad when eaten together?
May 2009
planetary science
The Planetary Air Leak
As Earth's atmosphere slowly trickles away into space, will our planet come to look like Venus?
What Makes Us Human?
Comparisons of the genomes of humans and chimpanzees are revealing those rare stretches of DNA that are ours alone
Could Food Shortages Bring Down Civilization?
The biggest threat to global stability is the potential for food crises in poor countries to cause government collapse. Those crises are brought on by ever worsening environmental degradation
How to Steal Secrets
Information thieves can now do an end run around encryption, networks and the operating system
Progress in Tissue
Pioneers in building living tissue report important advances over the past decade
Powering Nanorobots
Catalytic engines enable tiny swimmers to harness fuel from their environment and overcome the weird physics of the microscopic world
Ask the Experts How does food irradiation work? Is it safe? Indoor plants tend to grow toward the light, so why do trees outdoors grow straight instead of leaning toward the equator?
Apr 2009
life science
Saving the Honeybee
The mysterious ailment called colony collapse disorder has wiped out large numbers of the bees that pollinate a third of our crops. The causes turn out to be surprisingly complex, but solutions are emerging
Does Dark Energy Really Exist?
Maybe not. The observations that led astronomers to deduce its existence could have another explanation: that our galaxy lies at the center of a giant cosmic void
The Evolution of Primate Color Vision
Analyses of primate visual pigments show that our color vision evolved in an unusual way and that the brain is more adaptable than generally thought
The Post-Traumatic Stress Trap
A growing number of experts insist that the concept of post-traumatic stress disorder is itself disordered and that soldiers are suffering as a result
materials science
The Dawn of the Miniature Green Lasers
Semiconductors can generate laser light in all colors except one. But new techniques for growing laser diodes could soon make brilliant full-spectrum displays a reality
public health
Preventing the Next Pandemic
An international network for monitoring the flow of viruses from animals to humans might help scientists head off global epidemics
Ask the Experts If galaxies are all moving apart at ever increasing speed, how can they collide? If normal body temperature is about 98 degrees Fahrenheit, why do we feel hot at that air temperature?
Mar 2009
A Quantum Threat to Special Relativity
Entanglement, like many quantum effects, violates some of our deepest intuitions about the world. It may also undermine Einstein’s special theory of relativity
The World's Smallest Radio
A single carbon nanotube can function as a radio that detects and plays songs
Saving New Brain Cells
Fresh neurons arise in the adult brain every day. New research suggests that the cells ultimately help with learning complex tasks—and the more they are challenged, the more they flourish
The Power of Renewables
The need to tackle global climate change and energy security makes developing alternatives to fossil fuels crucial.
New Tactics Against Tuberculosis
The pandemic is growing in many places, and strains resistant to all existing drugs are emerging. To fight back, biologists are applying a host of cutting-edge drug development strategies
Monitoring for Nuclear Explosions
Detecting a test of a nuclear weapon has become so effective and reliable that no nation could expect to get away with secretly exploding a device having military significance
Insights: Escape from the Killing Fields As the world warms up, some species cannot move to cooler climes in time to survive. Camille Parmesan thinks humans should help—even if it means creating invasive species
Ask the Experts How do spacecraft orient themselves in the absence of magnetic poles? Is there any truth to the system they use on Star Trek?; How long will global uranium deposits fuel the world’s nuclear reactors at present consumption rates?
Feb 2009
Naked Singularities
The black hole has a troublesome sibling, the naked singularity. Physicists have long thought--hoped--it could never exist. But could it?
medicine, nanotech
Nanomedicine Targets Cancer
Viewing each human body as a system of interacting molecular networks and targeting disruptions in the system with nanoscale technologies can transform how disease is understood, attacked and possibly prevented
earth science
The Origin of the Land Under the Sea
The deep basins under the oceans are carpeted with lava that spewed from submarine volcanoes and solidified. Scientists have solved the mystery of how, precisely, all that lava reaches the seafloor
space science
New Dawn for Electric Rockets
Efficient electric plasma engines are propelling the next generation of space probes to the outer solar system
Sculpting the Brain
New studies are revealing how the brain’s convolutions take shape—findings that could aid the diagnosis and treatment of autism, schizophrenia and other mental disorders
climate change
The Greenhouse Hamburger
Producing beef for the table has a surprising environmental cost: it releases prodigious amounts of heat-trapping greenhouse gases
Insights: Chaos and the Catch of the Day There are fewer fish in the sea than ever. Complexity theory, argues mathematician George Sugihara, provides a counterintuitive way to revitalize the world’s fisheries
Working Knowledge: Smart Phones Touch Screens Redefine the Market
Ask the Experts Why do wind turbines have three narrow blades, whereas my fan at home has five wide blades?; What happens to the donor’s DNA in a blood transfusion?
Jan 2009
Darwin's Living Legacy
A Victorian amateur undertook a lifetime pursuit of slow, meticulous observation and thought about the natural world, producing a theory 150 years ago that still drives the contemporary scientific agenda
Testing Natural Selection
Biologists working with the most sophisticated genetic tools are demonstrating that natural selection plays a greater role in the evolution of genes than even most evolutionists had thought
From Atoms to Traits
Charles Darwin saw that random variations in organisms provide fodder for evolution. Modern scientists are revealing how that diversity arises from changes to DNA and can add up to complex creatures or even cultures
The Human Pedigree
Some 180 years after unearthing the first human fossil, paleontologists have amassed a formidable record of our forebears
This Old Body
Evolutionary hand-me-downs inherited from fish and tadpoles have left us with hernias, hiccups and other maladies
What Will Become of Homo sapiens?
Contrary to popular belief, humans continue to evolve. Our bodies and brains are not the same as our ancestors’ were—or as our descendants’ will be
Four Fallacies of Pop Evolutionary Psychology
Some evolutionary psychologists have made widely popularized claims about how the human mind evolved, but other scholars argue that the grand claims lack solid evidence
Evolution in the Everyday World
Understanding of evolution is fostering powerful technologies for health care, law enforcement, ecology, and all manner of optimization and design problems
The Science of Spore
A computer game illustrates the difference between building your own simulated creature and real-life natural selection
The Latest Face of Creationism
Creationists who want religious ideas taught as scientific fact in public schools continue to adapt to courtroom defeats by hiding their true aims under ever changing guises
Insights: A Theory of a Deadly Fusion The ability to spread underlies the killing power of cancer. The process occurs, John Pawelek thinks, when tumor cells fuse with white blood cells— an idea that, if right, could yield new therapies
Working Knowledge: New Designs Going Up Elevators
Ask The Experts How does solar power work? Why does my voice sound so different when it is recorded and played back?
Dec 2008
planetary science
The Restless World of Enceladus
Wrinkled landscapes and spouting jets on Saturn’s sixth-largest moon hint at underground waters
A New Molecule of Life
Peptide nucleic acid, a synthetic hybrid of protein and DNA, could form the basis of a new class of drugs—and of artificial life unlike anything found in nature
The Magic and the Brain
Magicians have been testing and exploiting the limits of cognition and attention for hundreds of years. Neuroscientists are just beginning to catch up
The Light Fantastic
Biological specimens yield extraordinary images in the hands of talented light microscopists
auto tech
Driving Toward Crashless Cars
Next-generation automotive safety technology could give us vehicles that are difficult to crash—and eventually may not need drivers at all
Taking Wing
At last, fossil and genetic findings elucidate the evolution of bats--and settle a long-standing debate over the origins of flight and echolocation
info tech
Can Phishing be Foiled?
Understanding the human factors that make people vulnerable to online criminals can improve both security training and technology
Insights: Turning Back the Cellular Clock Shinya Yamanaka discovered how to revert adult cells to an embryonic state. These induced pluripotent stem cells might soon supplant their embryonic cousins in therapeutic promise
Working Knowledge: Global Positioning System Where on Earth You Are
Nov 2008
A Sunshade for Planet Earth
Global warming has become such an overriding emergency that some climate experts are willing to consider schemes for partly shielding the planet from the sun’s rays. But no such scheme is a magic bullet
Jacking into the Brain
How far can science advance brain-machine interface technology? Will we one day pipe the latest blog entry or NASCAR highlights directly into the human brain as if the organ were an outsize flash drive?
The Long Arm of the Second Law
In seeming defiance of the second law of thermodynamics, nature is filled with examples of order emerging from chaos. A new theoretical framework resolves the apparent paradox
The Vaccine Search Goes On
The unfinished quest for an AIDS vaccine has become a search for new approaches to the problem
Can HIV Be Cured?
Eliminating HIV from the body would require flushing the virus out of its hiding places and preventing those reservoirs from being refilled. A tall order but perhaps not impossible
information science
DNA Computers for Work and Play
Logic gates made of DNA could one day operate in your bloodstream, collectively making medical decisions and taking action. For now, they play a mean game of in vitro tic-tac-toe
The Incredible Shrinking Scanner
A portable version of a room-size nuclear magnetic resonance machine can probe the chemistry and structure of objects ranging from mummies to tires
Insights: The Christian Man's Evolution A geneticist ordained as a Dominican priest, Francisco J. Ayala sees no conflict between Darwinism and faith. Convincing most of the American public of that remains the challenge
Working Knowledge: Dinner and a Show Microwave Ovens
Oct 2008
Follow the Bouncing Universe
Our universe may have started not with a big bang but with a big bounce—an implosion that triggered an explosion, all driven by exotic quantum-gravitational effects
Lighting Up the Brain
A clever combination of optics and genetics is allowing neuroscientists to map—and even control—brain circuits with unprecedented precision
Birth of an Ocean
Formation of an ocean is a rare event, one few scientists have ever witnessed. Yet this geophysical nativity is unfolding today in one of the hottest and most inhospitable corners of the globe. Visit the site in safety through this extraordinary photographic essay
The Search for Intelligence
IQ is easy to measure and reflects something real. But scientists hunting among our genes for the factors that shape intelligence are discovering they are more elusive than expected
info tech
Web Science Emerges
Studying the Web will reveal better ways to exploit information, prevent identity theft, revolutionize industry and manage our ever growing online lives
life science
Barcode of Life
Inspired by commercial barcodes, DNA tags could provide a quick, inexpensive way to identify species
With Open-Source Arms
A community of engineers, designers and innovators is collaborating online to make better prosthetic hands and arms for amputees. One of the lead engineers lost his own arm in Iraq
Insights: Outcalculating the Competition How did self-replicating molecules come to dominate the early earth? Using the mathematics of evolutionary dynamics, Martin A. Nowak can explain the change from no life to life
Working Knowledge: Competing Candidates Voting machines
Sep 2008
Privacy in an Age of Terabytes and Terror
Our jittery state since 9/11, coupled with the Internet revolution, is shifting the boundaries between public interest and "the right to be let alone"
Reflections on Privacy 2.0
Many issues posing as questions of privacy can turn out to be matters of security, health policy, insurance or self-presentation. It is useful to clarify those issues before focusing on privacy itself
Brave New World of Wiretapping
As telephone conversations have moved to the Internet, so have those who want to listen in. But the technology needed to do so would entail a dangerous expansion of the government’s surveillance powers
Keeping Your Genes Private
In spite of recent legislation, tougher laws are needed to prevent insurers and employers from discriminating on the basis of genetic tests
Tools of the Spy Trade
Night-vision cameras, biometric sensors and other gadgets already give snoops access to private spaces. Coming soon: palm-size "bug-bots"
RFID Tag--You're It
Tiny radio-frequency identification tags, long used for tracking supplies and inventory, are now appearing in a growing range of consumer items. A privacy activist argues that the devices pose new security risks to those who carry them, often unwittingly
Beyond Fingerprinting
Security systems based on anatomical and behavioral characteristics may offer the best defense against identity theft
Information of the World, Unite
Mashing everyone’s personal data, from credit-card bills to cell phone logs,into one all-encompassing digital dossier is the stuff of Orwellian nightmares. But it is not as easy as most people assume
How to Keep Secrets Safe
A versatile range of software solutions can protect the privacy of your information and online activities to any desired degree
Improving Online Security To protect against more numerous and sophisticated attacks by hackers, security professionals call for upgraded technology along with more attention to human and legal factors
The End of Privacy Young people share the most intimate details of personal life on social-networking Web sites, portending a realignment of the public and the private
Insights: Safety Dance over Plastic Just how harmful are baby bottles, eyeglasses and other bisphenol-A plastics? Patricia Hunt, who helped to bring the issue to light a decade ago, is still trying to sort it all out
Working Knowledge: Dry Dyes Instant photo developing
Aug 2008
Facing the Freshwater Crisis
As demand for freshwater soars, planetary supplies are becoming unpredictable. Existing technologies could avert a global water crisis, but they must be implemented soon
Why Migraines Strike
Biologists finally are unraveling the medical mysteries of migraine, from aura to pain
quantum physics
Quantum Computing with Ions
Researchers are taking the first steps toward building ultrapowerful computers that use individual atoms to perform calculations
public health
China's Children of Smoke
Epidemiologists find molecular clues to air pollution's impact on youngsters
planetary science
Bracing for a Solar Superstorm
A recurrence of the 1859 solar superstorm would be a cosmic Katrina, causing billions of dollars of damage to satellites, power grids and radio communications
materials science
Self-Cleaning Materials
The lotus plant's magnificent ability to repel dirt has inspired a range of self-cleaning and antibacterial technologies that may also help control microfluidic "lab-on-a-chip" devices
Magnifying Taste
Compounds that enhance the sweet and salty flavors of foods could combat obesity and heart disease
Insights: No More Cloning Around Like many stem cell pioneers, Ian Wilmut, the creator of Dolly the sheep, has jumped to an alternative approach. Is this the beginning of the end for embryonic cloning?
Working Knowledge: Warming and Cooling Home heat pumps
Jul 2008
The Self-Organizing Quantum
A new approach to the decades-old problem of quantum gravity goes back to basics and shows how the building blocks of space and time pull themselves together
New Jobs for Ancient Chaperones
Protective heat shock proteins present in every cell have long been known to counteract stress. Newly recognized roles in cancer and immunity make them potential therapeutic allies
Traces of a Distant Past
DNA furnishes an ever clearer picture of the multimillennial trek from Africa all the way to the tip of South America
Hands On Computing
Multi-touch screens could improve collaboration without a mouse or keyboard
No-Till: The Quiet Revolution
The age-old practice of turning the soil before planting a new crop is a leading cause of farmland degradation. Many farmers are thus looking to make plowing a thing of the past
The Neuroscience of Dance
Recent brain-imaging reveal some of the complex neural choreography behind our ability to dance
Simple Groups at Play
A new set of puzzles inspired by Rubik’s Cube offers puzzle lovers the chance to get acquainted with the secret twists and turns of mathematical entities called sporadic simple groups
Going with His Gut Bacteria The body and its intestinal flora produce chemicals with hidden health information, Jeremy Nicholson has found. Someday treating disease may mean treating those bacteria
Working Knowledge: Nimble Skyscrapers at Sea Cruise ships
Jun 2008
The Cosmic Origins of Time's Arrow
One of the most basic facts of life is that the future looks different from the past. But on a grand cosmological scale, they may look the same
Gaining Ground on Breast Cancer
The newest targeted therapies are helping doctors to tailor increasingly effective treatments to individual patients
info tech
Digital Image Forensics
Modern software has made manipulation of photographs easier to carry out and harder to uncover than ever before, but the technology also enables new methods of detecting doctored images
What Is a Species?
To this day, scientists struggle with that question. A better definition can influence which animals make the endangered list
The Tunguska Mystery
Finding a piece of the elusive cosmic body that devastated a Siberian forest a century ago could help save the earth in the centuries to come
The Neurobiology of Trust
Our inclination to trust a stranger stems in large part from exposure to a small molecule known for an entirely different task: inducing labor
The Ethics of Climate Change
Weighing our own prosperity against the chances that climate change will diminish the well-being of our grandchildren calls on economists to make hard ethical judgments
Insights: Beating the Flu in a Single Shot Walter Fiers found a protein segment on the influenza virus that could lead to a universal flu vaccine, which would end seasonal shots and provide pandemic protection
Working Knowledge: Library to Go E-Book Readers
May 2008
The Genesis of Planets
Theorists long imagined that the formation of young solar systems was a serene process with a stately progression, in which the eventual appearance of planets was a foregone conclusion. The latest evidence, however--including observations of worlds circling other stars--argues that planet formation is startlingly chaotic
Regulating Evolution
Most animals share similar genes. The staggering diversity in their physical forms springs from switches in the DNA that govern where and when those genes are active
info tech
Science 2.0
Is posting raw experimental data online, for all to see, a great tool or a great risk?
How Cells Clean House
Autophagy, a process that normally keeps cells in good working order, seems to be linked to aging and diseases such as Alzheimer's
Hooked from the First Cigarette
Cigarette addiction can arise astonishingly fast. New research could help make quitting easier
nuclear policy
Rethinking Nuclear Fuel Recycling
Plans are afoot to reuse spent reactor fuel in the U.S. But the advantages of the scheme pale in comparison with its dangers
Fighting Killer Worms
Bloodsucking worms called schistosomes are among the world's most worrisome human parasites. A new genome sequence and powerful genetic tools promise to help crack their secrets
Insights: Dark Forces at Work The universe will expand forever at an ever faster rate, thanks to an unseen energy. Astronomer Saul Perlmutter expects that new observations will soon illuminate the universe's dark side
Working Knowledge: Living Cover Green roofs
Apr 2008
space science
The Color of Plants on Other Worlds
If it isn't easy being green on Earth, where chlorophyll is well tuned to absorb most of the energy in our sun's yellow light, imagine the difficulties elsewhere in the galaxy. Plants growing on worlds around cooler, brighter or more tempestuous stars would need to rely on red, blue or even black pigments to survive. That insight offers astronomers new clues about what to look for in their search for extraterrestrial life
Regrowing Human Limbs
The ability to regenerate lost body parts--salamander-style--could revolutionize the treatment of amputations and major wounds
Reclaiming the Aral Sea
Mismanagement turned the world's fourth-largest lake into a dry, toxic wasteland. Now the northern part, at least, is coming back
Rulers of Light
A kind of laser light called an optical frequency comb can make atomic clocks and other instruments much more precise
The Doping Dilemma
Game theory suggests how to stop the pervasive abuse of drugs in cycling, baseball and other sports
materials science
Carbon Wonderland
A newly recognized form of carbon--single sheets of atoms--provides a rich lode of novel theoretical physics and practical applications
national security
Detecting Nuclear Smuggling
Radiation monitors at U.S. ports cannot reliably detect highly enriched uranium, which onshore terrorists could assemble into a nuclear bomb
Insights: At the Edge of Life's Code What happens in the black box between DNA and the proteins it produces? Chris Wiggins uses machine-learning techniques to peer inside
Working Knowledge: Weapons Revealed Whole-body scanning for airline passengers
Mar 2008
When Markets Beat the Polls
Internet-based financial markets may predict elections more reliably than polls do. They can augur future box-office returns and flu seasons, too.
The End of Cosmology?
"Will the big bang be forgotten? The accelerating cosmic expansion is wiping away every trace of the universe's origin."
White Matter Matters
Long regarded as passive support for cogitating neurons, the brain's white matter shows that it actively affects learning and mental illness.
info tech
The Limits of Quantum Computers
Futuristic quantum computers could be exceptionally fast at certain tasks, but for most problems they would only modestly outclass today's conventional machines.
The Bluefin in Peril
The only way to save the bluefin tuna, a marvelous but dwindling ocean fish, may be to domesticate it.
Space Wars
Recent pronouncements and actions by the U.S. and China threaten to ignite a new arms race in space that would be contrary to everyone's interests.
public health
Soliving the Massive Worker Health Puzzle
A sophisticated industrial health study--the largest one ever--struggles with an apparent cancer cluster and highlights why science cannot always protect workers on the job.
Insights: Not Tonight, Dear, I Have to Reboot Is love and marriage with robots an institute you can disparage? Computing pioneer David Levy doesn't think so--he expects people to wed droids by midcentury. Is that a good thing?
Working Knowledge: The Switch Is On The switch is on to compact fluorescents.
Feb 2008
The Discovery Machine
The Large Hadron Collider, the biggest and most complicated particle physics experiment ever seen, is nearing completion and is scheduled to start colliding protons this year
The Coming Revolutions in Particle Physics
No matter what the Large Hadron Collider finds, it is going to take physics into new territory
Building the Next-Generation Collider
To further investigate the intricacies of high-energy particle physics, researchers must construct a more powerful electron-positron collider
climate change
The Unquiet Ice
Abundant liquid water discovered underneath the great polar ice sheets could catastrophically intensify the effects of global warming on the rise of sea level around the world
RFID Powder
Radio-frequency identification (RFID) tags label all kinds of inventoried goods and speed commuters through toll plazas. Now tiny RFID components are being developed with a rather different aim: thwarting counterfeiters
Your Cells Are My Cells
Many, perhaps all, people harbor a small number of cells from genetically different individuals--from their mothers and, for women who have been pregnant, from their children. What in the world do these foreigners do in the body?
science and society
Building a Future on Science
Brazilian neuroscientist Miguel A. L. Nicolelis taps into the chatter of neurons to drive robotic prosthetics. Now he hopes to tap the potential of his country's population by building a network of "science cities"
Insights: Maverick against the Mendelians Autistic people generally do not have children, so why do autism genes persist? Michael Wigler thinks that he knows
Working Knowledge: Leap of Faith The video magic of blue screen
Jan 2008
tech leaders
The SciAm 50
Which researchers, companies and architects of industrial and government policy are leading the most important trends shaping tomorrow's technologies? Our annual roundup of world shakers gives credit where it is due
Taming Vessels to Treat Cancer
Drugs that restore order to the chaotic blood vessels inside a tumor open a window of opportunity for attacking it
A Solar Grand Plan
An ambitious scheme would enable solar power to end U.S. dependence on foreign oil and slash greenhouse gas emissions by 2050
public health
Second Thoughts about Fluoride
New research indicates that a cavity-fighting treatment could be risky if overused
Self-Powered Nanotech
Tiny systems that draw waste energy from their surroundings could power nanosize machines
earth science
Hotspots Unplugged
Long considered fixed founts of molten material from deep within the planet, the hotspots that raise islands now join the list of the earth's moving parts
The Human Instrument
When judged by its size, our vocal system fails to impress as a musical instrument. How, then, can it produce all those remarkable sounds?
Insights: Cooking Up Bigger Brains Our hominid ancestors could never have eaten enough raw food to create our large, calorie-hungry brains, Richard Wrangham claims. The secret to our evolution, this anthropologist says, is cooking
Working Knowledge: Perpetual Reset Machine The striking mechanics of bowling pinsetters
Dec 2007
Window on the Extreme Universe
The GLAST satellite is about to open up an unexplored region of the electromagnetic spectrum, where dark matter and other mysteries might be seen
Are Aliens among Us?
All life on Earth is generally understood to have descended from a common ancestor. But if cells evolved independently more than once, some microbes radically different from all known organisms might still survive in extreme environments of our planet. The search is on for evidence of these strangers
Making Carbon Markets Work
Limiting climate change without damaging the world economy depends on stronger and smarter market signals to regulate carbon dioxide
Radiant Information
State-of-the-art light microscopy from the Olympus BioScapes competition illuminates life exquisitely
Diet Advice from DNA?
Are personalized diets based on genetic tests cutting-edge science or high-tech horoscopes?
info tech
The Semantic Web in Action
Networks that handle data more intelligently are already here
The Many Worlds of Hugh Everett
Whatever became of the creator of the now celebrated quantum theory of multiple universes?
Working Knowledge: Progress Accelerates Adaptive cruise control
Nov 2007
The Great Cosmic Roller-Coaster Ride
Could cosmic inflation be a sign that our universe is in a far vaster realm?
Cell Defenses and the Sunshine Vitamin
Scientists now recognize that vitamin D does much more than build strong bones and that many people are not getting enough of it
Nuclear Weapons in a New World
Countries are altering their nuclear arsenals, prompting the U.S. to refurbish its own warheads
The Nuclear Threat
A look at strike capabilities worldwide, and how a bomb would affect single cities and people
A Need for New Warheads?
The U.S. government's proposal to build the first new muclear warhead in two decades raises a host of questions
Playing Defense against Lou Gehrig's Disease
Researchers have proposed potential therapies for a paralyzing disorder once thought to be untreatable
info tech
Brilliant Displays
A new technology can make cell phone and other displays bright and clear, even in the sun's glare
science and society
The Science of Doing Good
Information technology, satellite imaging and research carried out in disaster-relief areas have begun to transform humanitarian aid into a more efficient endeavor
Working Knowledge: Two Technologies Shine Digital projectors shine
Oct 2007
Conservation for the People
Pitting nature and biodiversity against people makes little sense. Many conservationists now argue that human health and well-being should be central to conservation efforts
space exploration
The Future of Space Exploration
The launch of the Soviet Sputnik satellite half a century ago inaugurated the Space Age. What comes next?
space exploration
To the Moon and Beyond
Humans are returning to the moon. This time the plan is to stay a while
space exploration
Five Essential Things to Do in Space
Planetary scientists have a quintet of goals for exploring the solar system
How Does Consciousness Happen?
One of the greatest mysteries in science is how brain activity gives rise to subjective experience. Two leading neuroscientists compare their differing theories
The Diamond Age of Spintronics
Revolutionary electronic devices can harness the spins of electrons instead of their charge. Such devices might one day enable room-temperature quantum computers--made of diamond
Experimental Drugs on Trial
A controversial lawsuit challenges the FDA's system of controlling access to experimental drugs and, some say, the scientific basis of drug approval
Big Lab on a Tiny Chip
Squeezing a chemistry lab down to fingernail size could provide instant medical tests at home and on the battlefield
Working Knowledge: Heating Up Geothermal energy
Sep 2007
A Question of Sustenance
Globalization ushered in a world in which more than a billion are overfed. Yet 800 million or so still suffer from hunger's persistent scourge
Eating Made Simple
How do you cope with a mountain of conflicting diet advice? Also: Paul Raeburn reviews the best scientific guidance on weight loss
Can Fat Be Fit?
Popular books have questioned the ill effects of being overweight. They are probably wrong
What Fuels Fat
Understanding obesity as a breakdown in the body's weight regulation could yield new ways to fight fat
This Is Your Brain on Food
Neuroimaging reveals what chocoholics have in common with drug addicts. Interview with Nora D. Volkow
public health
The World Is Fat
How can the poorest countries fight obesity?
Still Hungry
One eighth of the world does not have enough to eat
Sowing a Gene Revolution
A new green revolution based on genetically modified crops could help reduce poverty and hunger, but only if formidable institutional challenges are met
Is Your Food Contaminated?
New approaches to protect the food supply
Working Knowledge: Fresh from the Sea Desalination of seawater
Aug 2007
Race in a Bottle
Drugmakers are eager to develop medicines targeted at ethnic groups, but so far they have made poor choices based on unsound science
Predicting Wildfires
Fires are burning more acres than ever. Where will the next blazes ignite? Can we prevent them? Should we?
Windows on the Mind
Tiny flicks of the eyes underpin much of our ability to see. They may also reveal subliminal thoughts
The Physical Science behind Climate Change
Why climatologists are now so confident that human activity is to blame for a warming world
The Shark's Electric Sense
An astonishingly sensitive detector of electric fields helps sharks zero in on prey
Future Farming: A Return to Roots?
Agriculture would become more sustainable if major crop plants built deep, lasting root systems
Data Center in a Box
A shipping container stuffed with servers could usher in the era of cloud computing
Working Knowledge: Blu-ray vs. HD DVD High-definition video
Jul 2007
climate change
Warmer Oceans, Stronger Hurricanes
Evidence is mounting that global warming enhances a cyclone's damaging winds and flooding rains
The Memory Code
Researchers are closing in on the rules that the brain uses to lay down memories. Discovery of this memory code could lead to new ways to peer into the mind
A Malignant Flame
Understanding chronic inflammation, which contributes to heart disease, Alzheimer's and other ailments, may be a key to unlocking the mysteries of cancer
The Evolution of Cats
Genomic paw prints in the DNA of the world's wild cats have clarified the feline family tree and uncovered several remarkable migrations in their past
An Earth without People
Interview with Alan Weisman. One way to examine humanity's impact on the environment is to consider how the world would fare if all the people disappeared
info tech
Broadband Room Service by Light
Encoded light transmissions can provide the wireless devices in a room with multimedia Web services
science and society
Should Science Speak to Faith?
Two prominent defenders of science discuss how scientists ought to approach believers
Working Knowledge: In or Out? Hawkeye on the tennis court
Jun 2007
A Simpler Origin for Life
Energy-driven networks of small molecules may be more likely first steps for life than the commonly held idea of the sudden emergence of large self-replicating molecules such as RNA
Lifting the Fog around Anesthesia
Learning why current anesthetics are so potent and sometimes dangerous will lead to a new generation of safer targeted drugs
When Fields Collide
The history of particle cosmology shows that science can benefit from wrenching changes
Restoring America's Big, Wild Animals
Pleistocene rewilding--a proposal to bring back animals that disappeared from North America 13,000 years ago--offers an optimistic agenda for 21st-century conservation
info tech
Breaking Network Logjams
Network coding could dramatically enhance the efficiency of communications networks
Seeing Triple
Anticipated for decades, machines are finally displaying objects in three true dimensions
game theory
The Traveler's Dilemma
People playing this simple game consistently reject the rational choice. In fact, by acting illogically, they end up reaping a larger reward--an outcome that demands a new kind of formal reasoning
Working Knowledge: The Write Type Optical character recognition finds the write type
May 2007
space science
The Mystery of Methane on Mars and Titan
Could the methane in the atmospheres of Mars and Titan be caused by unusual geologic activity--or life?
Chromosomal Chaos and Cancer
Current wisdom on the role of genes in malignancy may not explain some of the features of cancer, but stepping back to look at the bigger picture inside cells reveals a view that just might
Preventing Blackouts
A smarter power grid that automatically responds to problems could reduce the rising number of debilitating blackouts
South America's Missing Mammals
An unexpected menagerie of unique mammal fossils is overturning long-held ideas about South America's geologic history
info tech, nanotech
Carbon Nanonets Spark New Electronics
Random networks of tiny carbon tubes could make possible low-cost, flexible devices such as "electronic paper" and printable solar cells
Eyes Open, Brain Shut
Brain-imaging techniques yield a better understanding of patients in the vegetative state
A Do-It-Yourself Quantum Eraser
Carry out a home experiment to illustrate one of the weirdest effects in quantum mechanics
Working Knowledge: Psst ... Hey, You Beams of sound
Apr 2007
The Ghosts of Galaxies Past
Strangely moving stars may be the remnants of past galaxies devoured by our Milky Way
Seeking the Connections: Alcoholism and Our Genes
Identifying the genetic influences on vulnerability to alcohol addiction can lead to more targeted treatments and help individuals make better-informed choices
info tech
The Promise of Plasmonics
A technology that squeezes electromagnetic waves into minuscule structures may yield superfast computer chips, ultrasensitive molecular detectors and perhaps even invisibility cloaks
animal behavior
Just How Smart Are Ravens?
Recent experiments show that these birds use logic to solve problems and that some of their abilities approach or surpass those of the great apes
The Movies in Our Eyes
The retina processes information much more than anyone has ever imagined, sending a dozen different movies to the brain
Gassing Up with Hydrogen
Researchers are working on ways for fuel-cell vehicles to hold the hydrogen they need for long-distance travel
A Cure for Rabies?
The survival of a Wisconsin teenager who contracted rabies may point the way to a treatment for this horrifying disease
Working Knowledge: Steer Clear Electronic stability control for autos
Technicalities: The Car Doctor Is In A way to diagnose engine problems without ever having to look under the hood
Mar 2007
Black Hole Blowback
A single black hole, smaller than the solar system, can control the destiny of an entire cluster of galaxies
Mapping the Cancer Genome
The Cancer Genome Atlas will help chart a new course across the complex landscape of human malignancies
info tech
A Digital Life
New systems may allow people to record everything that has touched their lives and to store all these data in a personal digital archive
Down Go the Dams
Many dams are being torn down these days, allowing rivers and the ecosystems they support to rebound. But ecological risks abound as well. Can they be averted?
New Predictors of Disease
Predictive autoantibodies appear in the blood years before people show symptoms of various disorders. Tests that detected these molecules could warn of the need to take preventive action
Diesels Come Clean
Improved engines and exhaust scrubbers, combined with a new fuel, will make energy-efficient diesels nearly as green as hybrids
Illusory Color and the Brain
The brain may not separate perception of color from perception of form and depth
Working Knowledge: Restoring Flow Left ventricular assist devices
Feb 2007
The Universe's Invisible Hand
Dark energy does more than hurry along the expansion of the universe. It also has a stranglehold on the shape and spacing of galaxies
Tracking an Ancient Killer
The case was cold--the bones in the mass grave were 70 million years old. But critical clues pointed to the killer's identity
climate change
Methane, Plants and Climate Change
The surprising discovery that living plants produce a potent greenhouse gas poses new questions for managing global warming
info tech
Making Silicon Lase
Scientists have at last persuaded silicon to emit laser beams. In a few years, computers and other devices will handle light as well as electrons
Spice Healer
An ingredient in curry shows promise for treating Alzheimer's, cancer and other diseases
consumer electronics
Digital TV at Last?
Analog TV broadcasting is set to end in two years, but its legacy could make the digital transition anything but smooth
Molecular Lego
Small molecular building blocks that snap together rigidly enable chemists to design and manufacture nanometer-scale structures in virtually any shape
Working Knowledge: Song Beams Satellite radio
Technicalities: Power Walker Nothing could match the Segway's initial hype, but how far has it come since?
Jan 2007
What Is a Planet?
The controversial new official definition of "planet," which banished Pluto, has its flaws but by and large captures essential scientific principles
Is Ethanol for the Long Haul?
Ethanol could displace gasoline, but it won't pay off until we find a way to distill cornstalks, not corn.
molecular biology
The Power of Riboswitches
Recently discovered RNA segments that act like on-off switches for genes may be targets for new classes of drugs
info tech
A Robot in Every Home
Microsoft's founding CEO predicts that robotics is on the verge of a grand awakening and that intelligent mobile devices will soon be everywhere
life science
Evolved for Cancer?
Some scientists hope to find new clues to help fight cancer by studying the evolutionary history of the disorder in our species
earth science
The Mississippi's Curious Origins
Mountains once blocked the interior of North America from the south. Geologic sleuthing reveals how that barrier was breached, allowing the Mississippi to reach the Gulf of Mexico
Better Ways to Target Pain
Improved understanding of the chemical pathway on which aspirin and Vioxx act may lead to superior analgesics
Working Knowledge: Grass vs. Plastic High-tech turf
Dec 2006
tech leaders
The Scientific American 50
Nanotech viruses, global warming, greener cars, stem cells and innovative funding all take a bow in our fifth annual salute to the research, business and policy leaders of technology
planetary science
The Red Planet's Watery Past
For a billion years, liquid water may have covered much of Mars
Seeking the Neural Code
How does a storm of electrical pulses in the brain translate into information?
Lucy's Baby
An amazing skeleton from 3.3 million years ago renews debate over the evolution of upright walking
The Ultimate White Light
"Supercontinuum" laser light could drive optical data transmission to record speeds
Cancer Clues from Pet Dogs
Studies of canine malignancies could improve medical care for humans and man's best friend alike
Weighty Matters
Replacing the century-old standard reference for mass measurement is a heavy challenge
Working Knowledge: Hot Commodity Why lithium batteries can overheat
Nov 2006
The Dark Ages of the Universe
Between the big bang and the formation of the first stars, the cosmos was utterly lightless. But astronomers can finally start peering into the darkness
Mirrors in the Mind
Mirror neurons, a special class of cells in the brain, may mediate our ability to mimic, learn and understand the actions and intentions of others
Broken Mirrors: A Theory of Autism
When the brain's mirror neuron system malfunctions, perhaps lack of empathy and other characteristics of autism are the result
info tech
Malware Goes Mobile
Consumers, phone makers and security companies must move quickly to quash the threat of new viruses targeting mobile devices
Reviving Dead Zones
Around the world, nutrients in runoff are turning coastal sea areas into oxygen-deprived dead zones hostile to life. But the example of the Black Sea shows these regions can be saved
Seeing with Superconductors
Sensors made of superconducting material can detect individual photons and have applications ranging from antiterrorism to astronomy
The Origin of the Greek Constellations
Was the Great Bear constellation named before hunter nomads first reached the Americas more than 13,000 years ago?
Working Knowledge: Gunk-Free Fiber The sticky problem of paper recycling
Oct 2006
How to Blow Up a Star
It is not as easy as you would think. Models of supernovae have failed to reproduce these explosions--until recently
info tech, nanotech
Viral Nanoelectronics
Viruses that coat themselves in selected substances can self-assemble into such devices as liquid crystals, nanowires and electrodes
cell biology
Peacekeepers of the Immune System
Regulatory T cells keep the immune system from attacking the body itself. Therapies using these cells could ease conditions from diabetes to transplant rejection
earth science
Impact from the Deep
Strangling heat and gases from the earth and sea, not asteroids, most likely caused several ancient mass extinctions. Could the same conditions build again?
A new mode of locomotion would enable robots to stand tall and move gracefully through busy everyday environments
Hydraulic Engineering in Prehistoric Mexico
Three thousand years ago precursors of the Aztecs built the first large-scale water management systems in the New World
The Promise of Molecular Imprinting
Tiny plastic imprints and mimics of biological molecules could speed drug discovery, warn of bioterror attacks and remove toxins from the environment
Working Knowledge: Steady Cam Image stabilization in digital cameras
Sep 2006
A Climate Repair Manual
Coping with global warming will take innovations in both energy technology and policy
A Plan to Keep Carbon in Check
Multiple technologies, each taking a slice out of carbon dioxide emissions, could slow warming
Fueling Our Transportation Future
New technologies, lighter vehicles and alternative fuels can lower greenhouse gas releases from cars and trucks
An Efficient Solution
In buildings and in industrial processes, using power more judiciously is the quickest, cheapest solution
What to Do about Coal
Coal is plentiful, but we must manage its environmental dark side
The Nuclear Option
Nuclear power could stave off more than a billion tons of carbon emissions annually
The Rise of Renewable Energy
Solar cells, wind turbines and biofuels are poised to become major energy sources
High Hopes for Hydrogen
Hydrogen-fueled cars could slash carbon emissions, but it won't happen soon
Plan B for Energy
Eventually, even more radical energy sources will be needed. Here are some possibilities under consideration
Working Knowledge: Tall Task A tall task for water towers
Aug 2006
The Strangest Satellites in the Solar System
With peculiar orbits that often move against the grain of the rest of the solar system, an odd breed of planetary satellites is reshaping ideas about the formation of the solar system
life science
The Real Life of Pseudogenes
Disabled genes, once dismissed as detritus on the genomic landscape, trace the path of evolution--and may not always be entirely dead
space science
Power for a Space Plane
Creating a revolutionary hypersonic jet engine that could propel a space plane to orbit affordably and routinely is a tough but seemingly achievable task
psychology, neuroscience
The Expert Mind
The mental processes of chess grandmasters are unlike those of novices, a fact that illuminates the development of expertise in other fields
earth science
Climate and the Evolution of Mountains
New studies of the Himalaya and the Tibetan Plateau suggest that climate and geology can be partners in a long, slow dance
info tech
A Great Leap in Graphics
Soon even home computers should be able to produce quick, high-quality 3-D graphics, thanks to speedier new ways to simulate the flight of light
The Fish and the Forest
Salmon carcasses left behind by predatory bears are unexpectedly important sources of nutrients for forests
Working Knowledge: Going Vertical How disk-drive makers raise storage capacities by making bits stand on end
Technicalites: Weather Gets Personal Here's the five-day forecast for your backyard
Jul 2006
Hubble's Top 10
As they wait for the space telescope to be serviced one last time, astronomers reflect on its discoveries over the past 16 years
Stem Cells: The Real Culprits in Cancer?
A dark side of stem cells--their potential to turn malignant--is at the root of a handful of cancers and may be the cause of many more. Eliminating the disease could depend on tracking down and destroying these elusive killer cells
physics, optics
The Quest for the Superlens
Built from "metamaterials" with bizarre, controversial optical properties, a superlens could produce images that include details finer than the wavelength of light that is used
life science
What Birds See
Evolution has endowed birds with a system of color vision that surpasses that of all mammals, including humans
A Power Grid for the Hydrogen Economy
Cryogenic, superconducting conduits could be connected into a "SuperGrid" that would simultaneously deliver electrical power and hydrogen fuel
CSI: Reality
Attorneys, investigators and educators have felt the impact of television's popular forensics programs
info tech
A Farewell to Keywords
The reigning obsession with search technology has elicited new ways of using images to track down information on the Web
Working Knowledge: Expanding Use Vascular stents
Jun 2006
earth science
The Secrets of Supervolcanoes
Microscopic crystals of volcanic ash are revealing surprising clues about the world's most devastating eruptions
Engineering Life: Building a Fab for Biology
Principles and practices learned from engineering successes can help transform biotechnology from a specialized craft into a mature industry
Wading in Waste
Thanks to unchecked development along America's coasts, disease-causing microbes are increasingly fouling beaches and shellfish beds
Toward Better Pain Control
Advances in understanding the cells and molecules that transmit pain signals are providing new targets for drugs that could relieve various kinds of pain--including those poorly controlled by existing therapies
info tech
Dependable Software by Design
Computers fly our airliners and run most of the world's banking, communications, retail and manufacturing systems. Now powerful analysis tools will at last help software engineers ensure the reliability of their designs
medicine, pharmacology
A New Assault on HIV
The constant search for weak points in the virus yields ideas for a wholly new class of drug
The Science behind Sudoku
Solving a Sudoku puzzle requires no math, not even arithmetic. Even so, the game poses a number of intriguing mathematical problems
Working Knowledge: Carbon Hooch Oil refineries
Technicalities: The Ultimate Blood Test A pricey way to determine health risks: 250 tests at once
May 2006
physics, cosmology
The First Few Microseconds
In recent experiments, physicists have replicated conditions of the infant universe--with startling results
info tech, nanotech
Bringing DNA Computer to Life
Tapping the computing power of biological molecules gives rise to tiny machines that can speak directly to living cells
earth science
The Birth of the Mighty Amazon
Insight into how the world's largest river formed is helping scientist explain the extraordinary abundance of plant and animal life in the Amazon rain forest
Blockbuster Dreams
New understanding of the biology behind a successful cancer therapy may lead to a drug that can treat an array of solid tumors
Giant Telescopes of the Future
The astronomical version of Moore's law says that telescopes double in size every few decades. But today's designers think they can build a telescope three, five or even 10 times bigger within a decade
Shutting Down Alzheimer's
New research reveals strategies for blocking the molecular processes that lead to this memory-destroying disease
When Slide Rules Ruled
Before electronic calculators, the mechanical slide rule dominated scientific and engineering computation
Working Knowledge: Cutting Work Robot mowers
Apr 2006
The Mysterious Origins of Solar Flares
New observations are beginning to reveal what triggers these huge explosions of the sun's atmosphere
New Hope for Defeating Rotavirus
Although its name is unfamiliar to many, rotavirus is the leading cause of severe childhood diarrhea worldwide and a frequent killer of young children in developing nations. Now--after 30 years of investigation--vaccines that may well conquer it are ready for market
info tech
Computing with Quantum Knots
A machine based on bizarre particles called anyons that represents a calculation as a set of braids in spacetime might be a shortcut to practical quantum computation
Why Are Some Animals So Smart?
The unusual behavior of orangutans in a Sumatran swamp suggests a surprising answer
Hybrid Vehicles Gain Traction
As car buyers turn to fuel-sipping gasoline-electric hybrid vehicles, a new generation of greener hybrids is just coming over the horizon
An Antibiotic Resistance Fighter
A compound that tweaks a pivotal protein may quell development of antibiotic resistance
Does Globablization Help or Hurt the World's Poor?
The answer is: both. The real question is how to maximize the help and minimize the hurt
Working Knowledge: Big Squeeze Jet engines
Technicalities: Sharp Shooter Sony's R1 combines near pro-quality images with live preview
Mar 2006
space science
Shielding Space Travelers
The perils of cosmic rays pose severe, perhaps insurmountable, hurdles to human spaceflight to Mars and beyond
Unlocking the Secrets of Longevity Genes
A handful of genes that control the body's defenses during hard times can also dramatically improve health and prolong life in diverse organisms. Understanding how they work may reveal the keys to extending human life span while banishing diseases of old age
The Dangers of Ocean Acidification
Much of the carbon dioxide given off from the burning of fossil fuels goes into the ocean, where it changes the acid balance of seawater. The repercussions for marine life may be enormous
info tech
Cognitive Radio
Smart radios and other new wireless devices will avoid transmission bottlenecks by switching instantly to nearby frequencies that they sense are clear
The Limits of Reason
Ideas of complexity and randomness originally suggested by Gottfried W. Leibniz in 1686, combined with modern information theory, imply that there can never be a "theory of everything" for all mathematics
Little Green Molecules
Chemists have invented a new class of catalysts that can destroy some of the worst pollutants before they get into the environment
innovations, computing
The Elusive Goal of Machine Translation
Statistical methods hold tha promise of moving computerized translation out of the doldrums
Working Knowledge: Spin and Swing Tiny motors
Feb 2006
Plasma Accelerators
A new method of particle acceleration in which the particles "surf" on a wave of plasma promises to unleash a wealth of applications
physiology, immunology
Intrigue at the Immune Synapse
Images of interacting immune cells reveal structured connections similar to the ones neurons use to communicate. Studying these synapses is providing new insights into how the cells form an information-sharing network to fight disease
Thwarting Nuclear Terrorism
Many civilian research reactors contain highly enriched uranium that terrorists could use to build nuclear bombs
Protecting New Orleans
Hurricanes Katrina and Rita devastated the Gulf Coast. The storm season starts again this June--and every June. Can coastal communities ever be safeguarded?
innovations, nanotech
Miniaturized Power
With nanobatteries, power sources finally shrink with the rest of electronics
Owning the Stuff of Life
Patents on DNA have not caused the severe disruption of biomedical research and societal norms anticipated by critics. But the deluge may be yet to come
info tech
Putting a Face on the First President
Solving a surprisingly long-standing mystery, a forensic anthropologist reconstructs what George Washington looked like as a young man
Working Knowledge: Into the Breach Levees
Technicalities: My Virtual War A disturbing stroll through a simulated battlefield
Jan 2006
The Mystery of Brown Dwarf Origins
By throwinig a wrench into the theories of planet and star formation, brown dwarfs may help fix them
Genomes for All
Next-generation technologies that make reading DNA fast, cheap and widely accessible are coming in less than a decade. Their potential to revolutionize research and bring about the era of truly personalized medicine means the time to start preparing is now
earth science
Tsunami: Wave of Change
In the tragic aftermath of the Indian Ocean tsunami of December 2004, scientists and warning centers are now better equipped to forecast and model these monstrous waves
Innovations from a Robot Rally
This year's Grand Challenge competition spurred advances in laser sensing, computer vision and autonomous navigation--not to mention a thrilling race for the $2-million prize
The Maternal Brain
Pregnancy and motherhood change the structure of the female mammal's brain, making mothers attentive to their young and better at caring for them
info tech
Recognition Engines
New computer designs process networked "streams" of data for better spam and virus detection
Protecting More than Animals
Reducing animal suffering often has the unexpected benefit of yielding more rigorous safety tests
Working Knowledge: No More Gears Continuously variable transmission
Dec 2005
tech leaders
The Scientific American 50
Flu preparedness, flexible electronics and stem cells all star in our fourth annual salute to the research, business and policy leaders of technology
An Echo of Black Holes
Sound waves in a fluid behave uncannily like light waves in space. Black holes even have acoustic counterparts. Could spacetime literally be a kind of fluid, like the ether of pre-Einsteinian physics?
Tackling Malaria
Interventions available today could lead to decisive gains in prevention and treatment--if only the world would apply them
Smarter Use of Nuclear Waste
Fast-neutron reactors could extract much more energy from recycled nuclear fuel, minimize the risks of weapons proliferation and markedly reduce the time nuclear waste must be isolated
public health
Sick of Poverty
New studies suggest that the stress of being poor has a staggeringly harmful influence on health
Getting a Leg Up on Land
Recent fossil discoveries cast light on the evolution of four-limbed animals from fish
Inside the Mind of a Savant
Kim Peek possesses one of the most extraordinary memories ever recorded. Until we can explain his abilities, we cannot pretend to understand human cognition
Working Knowledge: Better Exposure Digital x-rays
Technicalities: Easy Rider Automatic transmission makes cycling a breeze
Nov 2005
Preparing for a Pandemic
One day a highly contagious and lethal strain of influenza will sweep across all humanity, claiming millions of lives. It may arrive in months or not for years--but the next pandemic is inevitable. Are we ready?
The Illusion of Gravity
The force of gravity and one of the dimensions of space might be generated out of the peculiar interactions of particles and fields existing in a lower-dimensional realm
planetary science
Did Life Come from Another World?
New research indicates that microorganisms could have survived a journey from Mars to Earth
info tech, nanotech
Crossbar Nanocomputers
Crisscrossing assemblies of defect-prone nanowires could succeed today's silicon-based circuits
earth science
The Workings of an Ancient Nuclear Reactor
Two billion years ago parts of an African uranium deposit spontaneously underwent nuclear fission. The details of this remarkable phenomenon are just now becoming clear
The Neurobiology of the Self
Biologists are beginning to tease out how the brain gives rise to a constant sense of being oneself
The Land of Milk and Money
The first drug from a transgenic animal may be nearing approval
Working Knowledge: Case Cracked Nuts
Oct 2005
Ripples in a Galactic Pond
Astronomers are coming to realize that the beautiful shapes of galaxies are not merely incidental. They are essential to the galaxies' growth and development
New Bull's-Eyes for Drugs
A familiar class of cell-surface receptors turns out to offer an array of fresh targets that could yield new treatments for disorders ranging from HIV to obesity
earth science
A Cool Early Earth?
The textbook view that the earth spent its first half a billion years drenched in magma could be wrong. The surface may have cooled quickly--with oceans, nascent continents and the opportunity for life to form much earlier
The Forgotten Era of Brain Chips
The work of Jose Delgado, a pioneering star in brain-stimulation research four decades ago, goes largely unacknowledged today. What happened?
Better Than a Dog
The search is on for a sensor that bests a canine at detecting explosives
Founder Mutations
A special class of genetic mutations that often cause human disease is enabling scientists to trace the migration and growth of specific human populations over thousands of years
info tech
Smart Wi-Fi
Wireless access to the Internet via Wi-Fi is increasingly popular, so the technology is being upgraded to ensure that users get prompt, reliable service
Working Knowledge: Paving the Way Roads
Technicalities: Heavy-Metal Sweat Does an infrared sauna really detoxify the body?
Sep 2005
The Climax of Humanity
Demographically and economically, our era is unique in human history. Depending on how we manage the next few decades, we could usher in environmental sustainability--or collapse
Human Population Grows Up
As we swell toward nine billion in the next half a century, humanity will undergo historic changes in the balance between young and old, rich and poor, urban and rural. Our choices now and in years ahead will determine how well we cope with our coming of age
Can Extreme Poverty Be Eliminated?
Market economics and globalization are lifting the bulk of humanity out of extreme poverty, but special measures are needed to help the poorest of the poor
Sustaining the Variety of Life
A new understanding of how species become extinct suggests how to preserve them--and at a cost that doesn't break the bank
More Profit with Less Carbon
Focusing on energy efficiency will do more than protect Earth's climate--it will make businesses and consumers richer
The Big Potential of Small Farms
With the help of affordable irrigation and access to markets, farmers in the developing world can grow more food and climb out of poverty
public health
Public Health in Transition
Chronic disorders such as heart disease and diabetes, once common only in the industrial nations, are now sweeping the rest of the globe. Meanwhile the threat of infectious diseases still looms large. New public health priorities are urgently needed
Economics in a Full World
The global economy is now so large that society can no longer safely pretend it operates within a limitless ecosystem. Developing an economy that can be sustained within the finite biosphere requires new ways of thinking
How Should We Set Priorities?
The world faces no shortage of problems--or of good ideas to solve them. Which should we tackle next? Even as leaders converge on some answers, new markets are being set up to preempt politics
Working Knowledge: Private and Cool Smart glass
Aug 2005
Test-Tube Teeth
More complicated than they look, teeth are actually tiny organs. If tissue engineers can manufacture living replacement teeth, they would blaze a trail for engineering larger organs while leading dentistry into the age of regenerative medicine
The Early Evolution of Animals
Tiny fossils reveal that complex animal life is older than we thought--by at least as much as 50 million years
Is the Universe Out of Tune?
Like the discord of key instruments in a skillful orchestra quietly playing the wrong piece, mysterious discrepancies have arisen between theory and observations of the "music" of the cosmic microwave background. Either the measurements are wrong or the universe is stranger than we thought
info tech
Magnetic logic may usher in an era in which computing devices can change instantly from one type of hardware to another
Beating a Sudden Killer
When a young woman nearly died from a ruptured aneurysm, the author and the woman's husband began searching for ways to save other aneurysm patients from catastrophe
Mindful of Symbols
On the way to learning that one thing can represent another, young children often conflate the real item and its symbol. These errors show how difficult it is to start thinking symbolically
innovations, nanotech
Antibodies, often described as magic bullets, are actually more like tanks: big, complicated and expensive. Tinier "nanobodies," derived from camels and llamas, may be able to infiltrate a wider range of diseases at lower cost. That is the hope, at least, of one small start-up in Belgium
Working Knowledge: Ease the Grind Ball bearings
Technicalities: Heavenly Music in Your Hand Portable satellite radio is a palmtop cornucopia of music
Jul 2005
planetary science
The Many Faces of Mars
One rover found an ancient desert; the other, a once watery world. The Red Planet's diversity rivals Earth's
The Mysteries of Mass
Physicists are hunting for an elusive particle that would reveal the presence of a new kind of field that permeates all of reality. Finding that Higgs field will give us a more complete understanding about how the universe works
The Future of Stem Cells
A special report from Scientific American and Financial Times
climate change
Can We Bury Global Warming?
Pumping carbon dioxide underground to avoid warming the atmosphere is feasible, but only if several key challenges can be met
How Dinosaurs Grew So Large--and So Small
Overlooked clues to how fast the creatures grew and how long they lived lurk in their bones
info tech
Shrinking Circuits with Water
Semiconductor manufacturers are giving their products a dousing in the name of faster, smaller, cheaper
New Movement in Parkinson's
Recent genetic and cellular discoveries are among the advances pointing to improved treatments for this increasingly common disorder
Simulating Ancient Societies
Computer modeling is helping unravel the archaeological mysteries of the American Southwest
Working Knowledge: Make It Quick Rapid prototyping
Jun 2005
Buying Time in Suspended Animation
An ability to put the human body on hold could safeguard the critically injured or preserve donor organs for transport. Does the power to reversibly stop our biological clocks already lie within us?
Inconstant Constants
Do the inner workings of nature change with time?
info tech
Conversational Computers
Efforts to make computers speak naturally will let machines better communicate meaning
Obesity: An Overblown Epidemic?
A growing number of dissenting researchers accuse government and medical authorities--as well as the media--of misleading the public about the health consequences of rising body weights
Making Cold Antimatter
Low-energy atoms of antihydrogen will enable researchers to test a fundamental property of the universe
The Morning of the Modern Mind
Controversial discoveries suggest that the roots of our vaunted intellect run far deeper than is commonly believed
Doubt Is Their Product
Industry groups are fighting government regulation by fomenting scientific uncertainty
Working Knowledge: Lean and Mean Hybrid vehicles
Technicalities: The Multipath to Clarity Receiving HDTV over the air takes luck and lots of patience
May 2005
His Brain, Her Brain
It turns out that male and female brains differ quite a bit in architecture and activity. Research into these variations could lead to sex-specific treatments for disorders such as depression and schizophrenia
Quantum Black Holes
Physicists could soon be creating black holes in the laboratory
info tech
Neuromorphic Microchips
Compact, efficient electronics based on the brain's neural system could yield implantable silicon retinas to restore vision, as well as robotic eyes and other smart sensors
A Bolt out of the Blue
New research shows that lightning is a surprisingly complex and mystifying phenomenon
Can Chlamydia Be Stopped?
Chlamydia is a rampant sexually transmitted disease, the world's leading cause of preventable blindness and a possible contributor to heart disease. Recent discoveries are suggesting new ways to curtail its spread
planetary science
What Heated the Asteroids?
Collisions among asteroids in the early history of the solar system may help explain why many of these rocky bodies reached high temperatures
Molecular Treasure Hunt
A software tool elicits previously undiscovered gene or protein pathways by combing through hundreds of thousands of journal articles
Working Knowledge: Thin Is In Slim TV
Apr 2005
info tech
Stopping Spam
What can be done to stanch the flood of junk e-mail messages?
earth science
Probing the Geodynamo
Scientists have long wondered why the polarity of the earth's magnetic field occasionally reverses. Recent studies of our planet's churning interior are offering intriguing clues about how the next reversal may begin
biotech, genetics
The Alternative Genome
The old axiom "one gene, one protein" no longer holds true. The more complex an organism, the more likely it became that way by extracting multiple protein meanings from individual genes
Shaping the Future
Scientific uncertainty often becomes an excuse to ignore long-term problems, such as climate change. It doesn't have to be so
How Animals Do Business
Humans and other animals share a heritage of economic tendencies--including cooperation, repayment of favors and resentment at being shortchanged
materials science
Low-Temperature Superconductivity Is Warming Up
Magnesium diboride defies the once conventional wisdom about what makes a good superconductor. It becomes superconducting near the relativity warm temperature of 40 kelvins--which promises a variety of applications
A Toxin against Pain
For years, scientists have promised a new wave of drugs derived from sea life. A recently approved analgesic that is a synthetic version of a snail toxin has become one of the first marine pharmaceuticals
Working Knowledge: Uniform Variety Tennis balls
Technicalities: Hot Stuff New thermal cameras show the world in infrared
Mar 2005
Misconceptions about the Big Bang
Baffled by the expansion of the universe? You're not alone. Even astronomers frequently get it wrong
climate change
How Did Humans First Alter Global Climate?
A bold new hypothesis suggests that our ancestors' farming practices kicked off global warming thousands of years before we started burning coal and driving cars
info tech
If Smallpox Strikes Portland…
"EpiSims" unleashes virtual plagues in real cities to see how social networks spread disease. That knowledge might help stop epidemics
On the Road to Fuel-Cell Cars
Although fleets of fuel-cell prototypes are hitting the streets, basic technical and market obstacles must be hurdled before the clean, hydrogen-powered cars reach dealer showrooms
Taming Lupus
Teasing out the causes of this autoimmune disorder is a daunting challenge. But the payoff should be better, more specific treatments
Inventor of Dreams
Nikola Tesla, the father of today's AC electrical system and other key inventions, often failed to bring his visionary ideas to real-world fruition
Endangered Wild Equids
Wild zebra, asses and horses are being killed for meat, medicine and money. Combined with vanishing habitats and naturally slow reproduction, such predation threatens remaining populations
Working Knowledge: Take My Pixel Digital photography
Feb 2005
An Endangered Species in the Stomach
Is the decline of Helicobacter pylori, a bacterium living in the human stomach since time immemorial, good or bad for public health?
Atom Chips
Magnetic fields on a microchip can produce tiny, coherent clouds of atoms called Bose-Einstein condensates. The chips could have uses n ultraprecise sensors for aircraft and in quantum computing
The Littlest Human
A spectacular find in Indonesia reveals that a strikingly different hominid shared the earth with our kind in the not so distant past
info science
Seeking Better Web Searches
Deluged with superfluous responses to online queries, users will soon benefit from improved search engines that deliver customized results
Making Memories Stick
Some moments become lasting recollections while others just evaporate. The reason may involve the same processes that shape our brains to begin with
innovations, nanotech
Nanotubes in the Clean Room
Talismans of a thousand graduate projects may soon make their way into electronic memories
The New College Try
Innovation is alive and kicking on campus
Working Knowledge: Reducing a Roar Noise-canceling headphones
Technicalities: Every Breath You Take Now a high-tech shirt can record your vital signs all day and night
Jan 2005
life science
Immunity's Early-Warning System
The innate immune response constitutes the first line of defense against invading microbes and plays a role in inflammatory disease. Surprising insights into how this system operates could lead to new therapies for a host of infectious and immune-related disorders
The Midlife Crisis of the Cosmos
Although it is not as active as it used to be, the universe is still forming stars and building black holes at an impressive pace
info science
Considerate Computing
Digital gadgets demand ever more of our attention with their rude and thoughtless interruptions. Engineers are now testing computers, phones and cars that sense when you're busy and spare you from distraction
Capturing a Killer Flu Virus
The deadliest flu strain in history has been resurrected. What can the 1918 virus reveal about why it killed millions and where more like it may be lurking?
Eye of the Beholder
Wonders under the lens of the optical microscope
innovations, cryptography
Best-Kept Secrets
Quantum cryptography has marched from theory to laboratory to real products
Exploding the Self-Esteem Myth
Boosting people's sense of self-worth has become a national preoccupation. Yet surprisingly, research shows that such efforts are of little value in fostering academic progress or preventing undesirable behavior
Working Knowledge: Open Sesame Keyless entry
Dec 2004
tech leaders
The Scientific American 50
Our third annual salute to the people and institutions brightening our future recognizes accomplishments in stem cells, nanocomputers, mini fuel cells and more
The Brain's Own Marijuana
Research into natural chemicals that mimic marijuana's effects in the brain could help to explain--and suggest treatments for--pain, anxiety, eating disorders, phobias and other conditions
science and art
Optics and Realism in Renaissance Art
A much publicized assertion holds that 15th-century painters achieved a new level of realism with the help of lenses and mirrors. But recent findings cast doubt on that idea
The Dinosaurs of Arctic Alaska
Seventy-five million years ago, a group of hardy dinosaurs thrived in the harsh climate of what is now northern Alaska
The Case of the Pilfered Planet
Did the British steal Neptune?
Are Viruses Alive?
Although viruses challenge our concept of what "living" means, they are vital members of the web of life
Working Knowledge: Crowded Skies Air traffic control
Technicalities: More Than Just Music Accessories can enhance the iPod music player
Nov 2004
Rebuilding Broken Hearts
Biologists and engineers working together in the fledgling field of tissue engineering are within reach of one of their greatest goals: constructing a living human heart patch
Black Hole Computers
In keeping with the spirit of the age, researchers can think of the laws of physics as computer programs and the universe as a computer
climate change
Abrupt Climate Change
Winter temperatures plummeting six degrees Celsius and sudden droughts scorching farmland around the globe are not just the stuff of scary movies. Such striking climate jumps have happened before--sometimes within a matter of years
Holes in the Missile Shield
The national missile defense now being deployed by the U.S. should be replaced with a more effective system
info tech
Computing at the Speed of Light
Emerging ways to make photonic connections to electronic microchips may dramatically change the shape of computers in the decade ahead
Music and the Brain
What is the secret of music's strange power? Seeking an answer, scientists are piecing together a picture of what happens in the brains of listeners and musicians
A Split at the Core
Physics is forcing the microchip industry to redesign its most lucrative products. That is bad news for software companies
Working Knowledge: Keep the Beat Pacemakers
Oct 2004
A Universe of Disks
New research reveals the dynamics of the spinning disks of gas that surround young stars and gargantuan black holes
molecular biology
The Hidden Genetic Program of Complex Organisms
Biologists assumed that proteins alone regulate the genes of humans and other complex organisms. But an overlooked regulatory system based on RNA may hold the keys to development and evolution
Controlling Hurricanes
Can hurricanes and other severe tropical storms be moderated or deflected?
info tech
The Internet of Things
The principles that gave rise to the Internet are now leading to a new kind of network of everyday devices, an "Internet-0"
Dying to See
Studies of the lens of the eye not only could reveal ways to prevent cataracts but also might illuminate the biology of Alzheimer's, Parkinson's and other diseases in which cells commit suicide
Fixing the Vote
Electronic voting machines promise to make elections more accurate than ever before, but only if certain problems--with the machines and the wider electoral process--are rectified
Hitting the Genetic Off Switch
A host of start-ups is speeding development of a new class of drugs that block the action of RNA
Working Knowledge: Shock Absorbed Earthquake protection
Technicalities: Gadget Envy All-in-one cell phones can do just about anything
Sep 2004
The Patent Clerk's Legacy
In 1905 the musings of a functionary in the Swiss patent office changed the world forever. His intellectual bequest remains for a new generation of physicists vying to concoct a theory of everything
consumer electronics
Everyday Einstein
Finding your way out of the woods with GPS? Hanging a picture frame with a laser level? Making photocopies? Better thank Einstein
Atomic Spin-offs for the 21st Century
A new generation of technologies aims to put Einstein's theories to work in computers, hospitals - even submarines
Einstein's Compass
What was it about the magnetism of an iron bar that could divert Einstein from perfecting his celebrated theory of general relativity?
A Cosmic Conundrum
A new incarnation of Einstein's cosmological constant may point the way beyond general relativity
The String Theory Landscape
The theory of strings predicts that the universe might occupy one random "valley" out of a virtually infinite selection of valleys in a vast landscape of possibilities
Was Einstein Right?
Unlike nearly all his contemporaries, Albert Einstein thought quantum mechanics would give way to a classical theory. Some researchers nowadays are inclined to agree
The Search for Relativity Violations
To uncover evidence for an ultimate theory, scientists are looking for infractions of Einstein's once sacrosanct physical principle
A Century of Einstein
Scientific American has covered Einstein's theories - and the refinements and reactions to them - ever since scientists began to grasp the import of his landmark 1905 papers. Read on for a sampling of our reports, some by leading physicists of their times
Working Knowledge: String Theory Yo-yo
Aug 2004
Back to the Future of Cereals
Genomic studies of the world's major grain crops, together with a technology called marker-assisted breeding, could yield a new green revolution
space science
Electrodynamic Tethers in Space
By exploiting fundamental physical laws, tethers may provide low-cost eletrical power, drag, thrust, and artificial gravity for spaceflight
Virtual-Reality Therapy
Patients can get relief from pain or overcome their phobias by immersing themselves in computer-generated worlds
Nuclear Bunker Buster Bombs
New burrowing nuclear weapons could destroy subterranean military facilities - but their strategic and tactical utility is questionable
info tech
Next Stretch for Plastic Electronics
Organic semiconductor devices can make more than just bendable displays. They will find use in wearable electronics, chemical sensors, skin for robots and innumerable other applications
Questions That Plague Physics
Lawrence M. Krauss speaks about unfinished business
public health
Arsenic Crisis in Bangladesh
Arsenic in drinking water could severly poison 50 million people worldwide. Strategies being tested in Bangladesh might help prevent the problem
Working Knowledge: Seeing Inside Medical imaging
Technicalities: Crippled but Not Crashed Neural networks can help pilots land damaged planes
Jul 2004
The Extraordinary Deaths of Ordinary Stars
The demise of the sun in five billion years will be a spectacular sight. Like other stars of its ilk, the sun will unfurl into nature's premier work of art: a planetary nebula
Gene Doping
Gene therapy for restoring muscle lost to age or disease is poised to enter the clinic, but elite athletes are eyeing it to enhance performance. Can it be long before gene doping changes the nature of sport?
info tech, nanotech
Magnetic Field Nanosensors
Tiny devices that take advantage of a recently discovered physical effect called extraordinary magnetoresistance could be used in blazingly fast computer disk drives with huge capacities and in dozens of other applications involving the sensing of magnetic fields
earth science
When Methane Made Climate
Today methane-producing microbes are confined to oxygen-free settings, such as the guts of cows, but in Earth's distant past, they ruled the world
Detecting Mad Cow Disease
New tests can rapidly identify the presence of dangerous prions - the agents responsible for the malady - and several compounds offer hope for treatment
The Shapes of Space
A Russian mathematician has proved the century-old Poincaré conjecture and completed the catalogue of three-dimensional spaces. He might earn a $1-million prize
The Mystery of the Voynich Manuscript
New analysis of a famously cryptic medieval document suggests that it contains nothing but gibberish
Working Knowledge: Big Air Pipe organs
Jun 2004
planetary science
Saturn at Last!
After a seven-year journey, the Cassini-Huygens spacecraft is preparing to unveil the mysteries of Saturn, its rings and its giant moon, Titan
Nanotechnology and the Double Helix
DNA is more than just the secret of life - it is also a versatile component for making nanoscopic structures and devices
Lessons from the Wolf
Bringing the top predator back to Yellowstone has triggered a cascade of unanticipated changes in the park's ecosystem
info tech
Smart Sensors to Network the World
An emerging class of pillbox-size computers, outfitted with sensors and linked together by radios, can form perceptive networks able to monitor a factory, a store - even an ecosystem. Such devices will more intimately connect the cyberworld to the real world
The Stem Cell Challenge
What hurdles stand between the promise of human stem cell therapies and real treatments in the clinic?
Nuclear Explosions in Orbit
The spread of nuclear weapons and ballistic missiles raises fears of atomic attacks on the global satellite system
Technicalities: Security at Your Fingertips Fingerprint sensors can guard your computer data
May 2004
The Myth of the Beginning of Time
String theory suggests that the big bang was not the origin of the universe but simply the outcome of a preexisting state
Questions about a Hydrogen Economy
Much excitement surrounds the progress in fuel cells, but the quest for a hydrogen economy is no trivial pursuit
Synthetic Life
Biologists are crafting libraries of interchangeable DNA parts and assembling them inside microbes to create programmable, living machines
Freud Returns
Neuroscientists are finding that their biological descriptions of the brain may fit together best when integrated by psychological theories Freud sketched a century ago. Also: Counterpoint from J. Allan Hobson, who argues that Freud's thinking is still highly suspect
info tech
Retooling the Global Positioning System
From hikers navigating with handheld locators to pilots landing in zero-visibility conditions, the Global Positioning System now serves more than 30 million users. See what's coming next
planetary science
The Transit of Venus
When Venus crosses the face of the sun this June, scientists will celebrate one of the greatest stories in the history of astonomy
Working Knowledge: Clear Favorite Laser eye surgery
Puzzling Adventures: Jump Snatch Jumping to a conclusion
Apr 2004
The Other Half of the Brain
Mounting evidence suggests that glial cells, overlooked for half a century, may be nearly as critical to thinking and learning as neurons are
planetary science
The Hidden Members of Planetary Systems
The solar system consists of more than just planets; it is also a beehive of asteroids and comets. Is that the case for other planetary systems, too?
The Tyranny of Choice
Logic suggests that having options allows people to select precisely what makes them happiest. But, as studies show, abundant choice often makes for misery
info tech
The First Nanochips
As scientists and engineers continue to push back the limits of chipmaking technology, they have quietly entered into the nanometer realm
Evolution Encoded
New discoveries about the rules governing how genes encode proteins have revealed nature's sophisticated "programming" for protecting life from catastrophic errors while accelerating evolution
space science
Blastoffs on a Budget
Private ventures seeking to make routine access to space affordable see big potential in going small
Working Knowledge: Complete Burn Fuel injection
Technicalities: Plug-and-Play Robots Personal robots may soon be as cheap and customizable as personal computers
Puzzling Adventures: Bluffhead The game of Bluffhead
Mar 2004
planetary science
The Spirit of Exploration
NASA's rover fights the curse of the Angry Red Planet
info tech, robotics
A New Race of Robots
Around the U.S., engineers are finishing one-year crash projects to create robots able to dash 200 miles through the Mojave Desert in a day, unaided by humans. Scientific American tailed the odds-on favorite team for 10 months and found that major innovations in robotics are not enough to win such a contest. Obsession is also required
climate change
Defusing the Global Warming Time Bomb
Global warming is real, and the consequences are potentially disastrous. Nevertheless, practical actions, which would also yield a cleaner, healthier atmosphere, could slow, and eventually stop, the process
The Addicted Brain
Drug abuse produces long-term changes in the reward circuitry of the brain. Knowledge of the cellular and molecular details of these adaptations could lead to new treatments for the compulsive behaviors that underlie addiction
earth science
The Threat of Silent Earthquakes
A lack of rumbling does not necessarily make an earthquake harmless. Some of the quiet types could presage devasting tsunamis or larger, ground-shaking shocks
science and society
The Fairest Vote of All
All voting systems have drawbacks. But by taking into account how voters rank candidates, one system gives the truest reflection of the electorate's views
Working Knowledge: Rock Clock Quartz watches
Puzzling Adventures: Grid Speed Traffic on the grid
Feb 2004
Insights into Shock
Still a last step before death for thousands of people, shock is shedding some of it medical mystery and becoming more treatable
The Cosmic Symphony
New observations of the cosmic microwave background radiation show that the early universe resounded with harmonious oscillations
Reading the Blueprints of Creation
The latest maps of the cosmos have surveyed hundreds of thousands of galaxies, whose clustering has grown from primordial fluctuations
From Slowdown to Speedup
Distant supernovae are revealing the crucial time when the expansion of the universe changed from decelerating to accelerating
Out of the Darkness
Maybe cosmic acceleration isn't caused by dark energy after all but by an inexorable leakage of gravity out of our world
info tech
Better Displays with Organic Films
Light-emitting organic materials offer brighter and more efficient displays than LEDs. An you'll be able to unroll them across a tabletop
The Case of the Unsolved Crime Decline
Criminologists have not yet cracked the case, but they now know more about why U.S. crime rates plummeted in the 1990s - and how to help keep them down
Working Knowledge: Data Driven Automobile black box
Technicalities: A Walk in the Woods Satellites show the way in the new sport of geocaching
Puzzling Adventures: All or Nothing Numerical messages
Jan 2004
Our Growing, Breathing Galaxy
Long assumed to be a relic of the distant past, the Milky Way turns out to be a dynamic, living object
Decoding Schizophrenia
A fuller understanding of signaling in the brain of people with this disorder offers new hope for improved therapy
info tech
RFID: A Key to Automating Everything
Already common in security systems and tollbooths, radio-frequency identification tags and readers stand poised to take over many processes now accomplished by human toil
Atoms of Space and Time
We perceive space and time to be continuous, but if the amazing theory of loop quantum gravity is correct, they actually come in discrete pieces
Women and Men at Çatalhöyük
The largest known Neolithic settlement yields clues about the roles played by the two sexes in early agricultural societies
Spring Forward
As temperatures rise sooner in spring, interdependent species in many ecosystems are shifting dangerously out of sync
The Curious History of the First Pocket Calculator
It was called the Curta, and it proved lifesaving when its inventor was trapped in a Nazi concentration camp
Working Knowledge: Phantom Gain Virtual 1st down marker
Puzzling Adventures: Verifying Your Circuits Verifying circuits
Dec 2003
tech leaders
The Scientific American 50
Our second annual salute to the elite of research, industry and politics whose accomplishments are shaping a better, wiser technological future for the world
Does Race Exist?
If races are defined as genetically discrete groups, no. But researchers can use some genetic information to group individuals into clusters with medical relevance
planetary science
The New Moon
Recent lunar missions have shown that there is still much to learn about Earth's closest neighbor
The Equivocal Success of the Wright Brothers
The Wrights used aerial control as the key to building and flying the first airplane. But trying to refine their invention in secret nearly cost them their glory
earth science
The Day the World Burned
The dinosaur-killing impact set off a wave of wildfires that consumed Earth's forests
The Unseen Genome: Beyond DNA
DNA was once considered the sole repository of heritable information. But biologists are starting to decipher a separate, much more malleable layer of information encoded within the chromosomes. Genetics, make way for epigenetics
Working Knowledge: At the Moment Electronic skis
Technicalities: Science for Cops A behind-the-scenes look at a high-tech police lab
Puzzling Adventures: You Don't Say! Parallel repetition
Nov 2003
The Unseen Genome: Gems among the Junk
Just when scientists thought they had DNA almost figured out, they are discovering in chromosomes two vast, but largely hidden, layers of information that affect inheritance, development and disease
space science
The Asteroid Tugboat
To prevent an asteroid from hitting Earth, a space tug equipped with plasma engines could give it a push
An Army of Small Robots
For robot designers these days, small is beautiful
The Future of String Theory - A Conversation with Brian Greene
The physicist and best-selling author demystifies the ultimate theories of space and time, the nature of genius, multiple universes, and more
Stranger in a New Land
Stunning finds in the Republic of Georgia upend long-standing ideas about the first hominids to journey out of Africa
Flying on Flexible Wings
Future aircraft may fly more like birds, adapting geometrics of their wings to best suit changing flight conditions
Why We Sleep
The reasons that we sleep are gradually becoming less enigmatic
Working Knowledge: Staying Power Nails and staples
Puzzling Adventures: Liquid Switchboard Liquid switchboard
Oct 2003
The Unexpected Youth of Globular Clusters
Conventional wisdom says that globular star clusters are the stodgy old codgers of the universe, but it turns out that many of these clusters are young
materials science
Artificial Muscles
Novel motion-producing devices - actuators, motors, generators - based on polymers that change shape when stimulated electrically are nearing commercialization
Meltdown in the North
Sea ice and glaciers are melting, permafrost is thawing, tundra is yielding to shrubs - and scientists are struggling to understand how these changes will affect not just the Arctic but the entire planet
Tumor-Busting Viruses
A new technique called virotherapy harnesses viruses, those banes of humankind, to stop another scourge--cancer
space science
China's Great Leap Upward
By boosting astronauts into orbit, China hopes to become the newest superpower in space
The Economics of Child Labor
Campaigns against child labor are most likely to succeed when they combine the long arm of the law with the invisible hand of the marketplace
Working Knowledge: Cool Shirt Smart fabrics
Technicalities: The Infinite Arcade Machine Building the world's largest video arcade - in your family room
Puzzling Adventures: Strategic Bullying Strategic bullying
Sep 2003
Brain, Repair Yourself
How do you fix a broken brain? The answers may literally lie within our heads. The same approaches might also boost the power of an already healthy brain
The Quest for a Smart Pill
New drugs to improve memory and cognitive performance in impaired individuals are under intensive study. Their possible use in healthy people already triggers debate
Stimulating the Brain
Activating the brain's circuitry with pulsed magnetic fields may help ease depression, enhance cognition, even fight fatigue
Mind Readers
Brain-scanning machines may soon be capable of discerning rudimentary thoughts and separating fact from fiction
The Mutable Brain
Score one for believers in the adage "use it or lose it." Targeted mental and physical exercises seem to improve the brain in unexpected ways
Taming Stress
An emerging understanding of the brain's stress pathways points toward treatments for anxiety and depression beyond Valium and Prozac
Diagnosing Disorders
Psychiatric illnesses are often hard to recognize, but genetic testing and neuroimaging could someday be used to improve detection
Working Knowledge: On the Money Bill validators
Puzzling Adventures: Missing Hiker Find the missing hiker
Aug 2003
Censors of the Genome
Biologists have been surprised to discover that most animal and plant cells contain a built-in system to silence individual genes by shredding the RNA they produce. Biotech companies are already working to exploit it
info tech
Demystifying the Digital Divide
The simple binary notion of technology haves and have-nots doesn't quite compute
Rethinking the "Lesser Brain"
Long thought to be solely the brain's coordinator of body movement, the cerebellum is now known to be active during a wide variety of cognitive and perceptual activities
Information in the Holographic Universe
Theoretical results about black holes suggest that the universe could be like a gigantic hologram
Questioning the Delphic Oracle
When science meets religion at this ancient Greek site, the two turn out to be on better terms than scholars had originally thought
Planet of the Apes
During the Miocene epoch, as many as 100 species of apes roamed throughout the Old World. New fossils suggest that the ones that gave rise to living great apes and humans evolved not in Africa but Eurasia
Working Knowledge: Seeing Green Night vision
Technicalities: Converging on the Couch New devices connect the stereo and TV to the home data network
Puzzling Adventures: Short Taps Outwitting spies
Jul 2003
The Galactic Odd Couple
Why do giant black holes and stellar baby booms, two phenomena with little in common, so often go together?
Counting the Last Fish
Overfishing has slashed stocks - especially of large predator species - to an all-time low worldwide, according to new data. If we don't manage this resource, we will be left with a diet of jellyfish and plankton stew
info tech
Antennas Get Smart
Adaptive antenna arrays can vastly improve wireless communications by connecting mobile users with virtual wires
Untangling the Roots of Cancer
Recent evidence challenges long-held theories of how cells turn malignant - and suggests new ways to stop tumors before they spread
Uncovering the Keys to the Lost Indus Cities
Recently excavated artifacts from Pakistan have inspired a reevaluation of one of the great early urban cultures - the enigmatic Indus Valley civilization
In what has become almost routine, the heart-lung machine "breathes" for patients during coronary-bypass operations. But could this lifesaving device have a dark side?
Insights: Terms of Engagement Irving Weissman directs a new institute dedicated to the cloning of human embryonic stem cells. Just don't call it cloning
Working Knowledge: Fine Focus Scanning electron microscopes
Puzzling Adventures: High Spies Tracking contraband shipments
Jun 2003
Shoot This Deer
Chronic wasting disease, a cousin of mad cow disease, is spreading among wild deer in parts of the U.S. Left unchecked, the fatal sickness could threaten North American deer populations - and maybe livestock and humans
The Unearthly Landscapes of Mars
The Red Planet is no dead planet
Self-Repairing Computers
By embracing the inevitability of system failures, recovery-oriented computing returns service faster
Pandora's Baby
In vitro fertilization was once considered by some to be a threat to our very humanity. Cloning inspires similar fears
The Dawn of Physics Beyond the Standard Model
The Standard Model of particle physics is at a pivotal moment in its history: it is both at the height of its success and on the verge of being surpassed
info science
Chain Letters and Evolutionary Histories
A study of chain letters shows how to infer the family tree of anything that evolves over time, from biological genomes to languages to plagiarized schoolwork
May 2003
Parallel Universes
Not just a staple of science fiction, other universes are a direct implication of cosmological observations
Hearing Colors, Tasting Shapes
People with synesthesia - whose senses blend together - are providing valuable clues to understanding the organization and functions of the human brain
info tech
Scale-Free Networks
Scientists have recently discovered that various complex systems have an underlying architecture governed by shared organizing principles. This insight has important implications for a host of applications, from drug development to Internet security
The Iceman Reconsidered
Where was the Iceman's home and what was he doing at the high mountain pass where he died? Painstaking research - especially of plant remains found with the body - contradicts many of the initial speculations
The Orphan Drug Backlash
The Orphan Drug Act of 1983 was supposed to provide incentives for private industry to develop needed, but unprofitable, drugs to treat rare diseases. It has done so, but not without eliciting controversy
Working Knowledge: Catch a Wave Antennas
Puzzling Adventures: Bounded Regrets Competitive analysis and the regret ratio
Apr 2003
Solving the Solar Neutrino Problem
The Sudbury Neutrino Observatory has solved a 30-year-old mystery by showing that neutrinos from the sun change species en route to the earth
Where a Pill Won't Reach
How to get drugs where they need to go
earth science
Mount Etna's Ferocious Future
Europe's biggest and most active volcano is growing more dangerous. Luckily, the transformation is happening slowly
A Conversation with James D. Watson
The co-discoverer of DNA's double helix reflects on the molecular model that changed both science and society
life science
Questioning the Oldest Signs of Life
In the past year scientists have been forced to reconsider how they identify life in the most ancient rocks on earth - and elsewhere in the solar system
info tech
The Grid: Computing without Bounds
By linking digital processors, storage systems and software on a global scale, grid technology is poised to transform computing from an individual and corporate activity into a general utility
The Lowdown on Ginkgo Biloba
This popular herbal supplement may slightly improve your memory, but you can get the same effect by eating a candy bar
Working Knowledge: Potent Patches Transdermal drug delivery
Technicalities: Screen Writing The tablet PC is a high-tech tool for scribblers
Puzzling Adventures: The Graph of Life Graphing the origins of species
Mar 2003
The Search for Dark Matter
Dark matter is usually thought of as something "out there." But we will never truly understand it unless we can bring it down to earth
energy, environment
Dismantling Nuclear Reactors
Taking apart a nuclear power plant that has reached the end of its life is a complicated task. But not for the reasons you might expect
Restoring Aging Bones
The bone decay of osteoporosis can cripple, but an improved understanding of how the body builds and loses bone is leading to ever better prevention and treatment options
info tech
Digital Entertainment Jumps the Border
New broadcasting technologies are challenging the restrictions on the viewing of American television shows and films in other countries
Which Came First, the Feather or the Bird?
A long-cherished view of how and why feathers evolved has now been overturned
Bugs in the Brain
Time for a bit of humility. Some microorganisms can manipulate neural circuitry better than we can
Working Knowledge: No Two Alike Fingerprint readers
Puzzling Adventures: Safecracking The safecracker's strategy
Feb 2003
Some stars are magnetized so intensely that they emit huge bursts of magnetic energy and alter the very nature of the quantum vacuum
Why? The Neuroscience of Suicide
New research addresses the wrenching question left when someone ends his or her own life
info tech
Evolving Inventions
Computer programs that function via Darwinian evolution are creating inventions that are novel and useful enough to be patented
Explaining Frog Deformities
An eight-year investigation into the cause of a shocking increase in deformed amphibians has sorted out the roles of three prime suspects
Satellite-Guided Munitions
Highly accurate yet affordable strike weapons, proved in Afghanistan, are the latest upgrades to America's arsenal
Drink to Your Health?
Three decades of research shows that drinking small to moderate amounts of alcohol has cardiovascular benefits. A thorny issue for physicians is whether to recommend drinking to some patients
Working Knowledge: Carbon Copy Synthetic diamonds
Technicalities: Robots That Suck Have they finally come out with a robot for the rest of us?
Puzzling Adventures: Five Trusty Flares Choosing trustworthy flares
Jan 2003
New Light on Medicine
Pigments that turn caustic on exposure to light can fight cancer, blindness and heart disease. Their light-induced toxicity may also help explain the origin of vampire tales
info tech, nanotech
The Nanodrive Project
Inventing a nanotechnology device for mass production and consumer use is trickier than it sounds
An Ancestor to Call Our Own
Controversial new fossils could bring scientists closer than ever to the origin of humanity
Rebuilding the Food Pyramid
The dietary guide introduced a decade ago has led people astray. Some fats are healthy for the heart, and many carbohydrates clearly are not
earth science
Earthquake Conversations
Contrary to prevailing wisdom, large earthquakes can interact in unexpected ways. This exciting discovery could dramatically improve scientists' ability to pinpoint future shocks
The Science of Bubbly
Scientists study the nose-tickling effervescence of champagne - an alluring and unmistakable aspect of its appeal
Working Knowledge: Scratch Match Ballistics
Puzzling Adventures: Protein Chime Timing with proteins
Dec 2002
tech leaders
The Scientific American 50
Our first annual celebration of visionaries from the worlds of research, industry and politics whose recent accomplishments point toward a brighter technological future for everyone
The Brightest Explosions in the Universe
Every time a gamma-ray burst goes off, a black hole is born
The Enigma of Huntington's Disease
Nearly 10 years after scientists isolated the gene responsible for Huntington's, they are still searching for how it wreaks its devastation
climate change
On Thin Ice
How soon humanity will have to move inland to escape rising seas depends in great part on how quickly West Antarctica's massive ice sheet shrinks. Scientists are finally beginning to agree on what controls the size of the sheet and its rate of disintegration
Food for Thought
Dietary change was a driving force in human evolution
info tech
Order in Pollock's Chaos
Computer analysis is helping to explain the appeal of Jackson Pollock's paintings. The artist's famous drips and swirls create fractal patterns, similar to those formed in nature by trees, clouds and coastlines
Working Knowledge: Superhot Dots Ink-jet printing
Technicalities: Getting Real What's next in computer displays? Depth and shadows
Puzzling Adventures: Plumbers Find the blabbermouth
Nov 2002
When Stars Collide
When two stars smash into each other, it can be a very pretty sight (as long as you're not too close by). These occurrences were once considered impossible, but they have turned out to be common in certain galactic neighborhoods
The Long Arm of the Immune System
Dendritic cells catch invaders and tell the immune system when and how to respond. Vaccines depend on them, and scientists are even employing the cells to stir up immunity against cancer
Gladiators: A New Order of Insect
A mystery in amber is solved on a desert mountain with a discovery that has stunned entomologists
info tech
Rules for a Complex Quantum World
An exciting new fundamental discipline of research combines information science and quantum mechanics
Weapons of Mass Disruption
Radiological terror weapons could blow radioactive dust through cities, causing panic, boosting cancer rates and forcing costly cleanups
Burning Questions
Scientists work to understand and control the plague of wildfires in the West
Working Knowledge: See the Wind Weather radar
Puzzling Adventures: Perfect Billiards Perfect billiards: working the angles
Oct 2002
Controlling Robots with the Mind
People with nerve or limb injuries may one day be able to command wheelchairs, prosthetics and even paralyzed arms and legs by "thinking them through" the motions
The Emptiest Places
Space comes in degrees of emptiness, but even in the wasteland between galaxies it is not a complete void
Vehicle of Change
Hydrogen fuel-cell cars could be the catalyst for a cleaner tomorrow
Skin Deep
Throughout the world, human skin color has evolved to be dark enough to prevent sunlight from destroying the nutrient folate but light enough to foster the production of vitamin D
Technology against Terror
Biologists and engineers are devising early-warning systems that can detect a bioterrorist attack in time to blunt its effects
info tech
Lightning Rods for Nanoelectronics
Electrostatic discharges threaten to halt further shrinking and acceleration of electronic devices in the future
Working Knowledge: Vying for Eyes Flat displays
Technicalities: Computers for the Third World The Simputer is a handheld device designed for rural villagers
Puzzling Adventures: Prime Spies Prime spies
Sep 2002
Real Time
The pace of living quickens continuously, yet a full understanding of things temporal still eludes us
That Mysterious Flow
From the fixed past to the tangible present to the undecided future, it feels as though time flows inexorably on. But that is an illusion
A Hole at the Heart of Physics
Physicists can't seem to find the time - literally. Can philosophers help?
How to Build a Time Machine
It wouldn't be easy, but it might be possible
From Instantaneous to Eternal
The units of time range from the infinitesimally brief to the interminably long. The descriptions given here attempt to convey a sense of this vast chronological span
Times of Our Lives
Whether they're counting minutes, months or years, biological clocks help keep our brains and bodies running on schedule
Remembering When
Several brain structures contribute to "mind time," organizing our experiences into chronologies of remembered events
Clocking Cultures
What is time? The answer varies from society to society
A Chronicle of Timekeeping
Our conception of time depends on the way we measure it
Ultimate Clocks
Atomic clocks are shrinking to microchip size, heading for space - and approaching the limits of useful precision
Puzzling Adventures: Venture Bets Investments and probabilities
Aug 2002
The Serious Search for an Anti-Aging Pill
In government laboratories and elsewhere, scientists are seeking a drug able to prolong life and youthful vigor. Studies of caloric restriction are showing the way
Does Dark Matter Really Exist?
Ninety-five percent of the universe has gone missing. Or has it?
The Ocean's Invisible Forest
Marine phytoplankton play a critical role in regulating the earth's climate. Could they also be used to combat global warming?
info tech
Computers without Clocks
Asynchronous chips improve computer performance by letting each circuit run as fast as it can
Combating the Terror of Terrorism
The psychological damage caused by the attacks of September 11 mirrored the physical destruction and showed that protecting the public's mental health must be a component of the national defense
Saving Dying Languages
Linguists have known for years that thousands of the world's languages are at grave risk of extinction. Yet only recently has the field summoned the will - and the money - to do much about it
Working Knowledge: Safety at a Cost Smart cards
Technicalities: Machine Chic The Poma wearable computer is flashy but not very functional
Puzzling Adventures: Repellanoids Repellanoid circumference
Jul 2002
Sweet Medicines
Sugars play critical roles in many cellular functions and in disease. Study of those activities lags behind research into genes and proteins but is beginning to heat up. The discoveries promise to yield a new generation of drug therapies
info tech
Last Mile by Laser
Short-range infrared lasers could beam advanced broadband multimedia services directly into homes and offices
The Nose Takes a Starring Role
The star-nosed mole has what is very likely the world's fastest and most fantastic nose
The Trials of an Artificial Heart
A year after doctors began implanting the AbioCor in dying patients, the prospects of the device are uncertain
Uncovering Supersymmetry
A strange, elusive phenomenon called supersymmetry was conceived for elementary particle physics - but has come to light in nuclei of platinum and gold
15 Answers to Creationist Nonsense
Opponents of evolution want to make a place for creationism by tearing down real science, but their arguments don't hold up
Working Knowledge: Turn Turn Turn Windmills
Puzzling Adventures: Blind Justice Mathematical justice
Jun 2002
Hope in a Vial
Will there be an AIDS vaccine anytime soon?
The Life Cycle of Galaxies
Astronomers are on the verge of explaining the enigmatic variety of galaxies
Disturbing Behaviors of the Orangutan
Studies of these great apes show that some males pursue an unexpected and disquieting evolutionary strategy
info tech
Microelectronic devices that function by using the spin of the electron are a nascent multibillion-dollar industry - and may lead to quantum microchips
Islands of Genius
Artistic brilliance and a dazzling memory can sometimes accompany autism and other developmental disorders
The Complexity of Coffee
One of life's simple pleasures is really quite complicated
No Truth to the Fountain of Youth
Fifty-one scientists who study aging have issued a warning to the public: no anti-aging remedy on the market today has been proved effective. Here's why they are speaking up
Working Knowledge: Hidden Guides Gyroscope guidance
Technicalities: Whatever You Say With speech-recognition software, your voice is the computer's command
Puzzling Adventures: Privacy Taboos Privacy among the Paranoimos
May 2002
Atherosclerosis: The New View
It causes chest pain, heart attack and stroke, leading to more deaths every year than cancer. The long-held conception of how the disease develops turns out to be wrong
planetary science
Journey to the Farthest Planet
Scientists are finally preparing to send a spacecraft to Pluto and the Kuiper Belt, the last unexplored region in our planetary system
info tech
Wireless Data Blaster
Radio's oldest technology is providing a new way for portable electronics to transmit large quantities of data rapidly without wires
The Mammals That Conquered the Seas
New fossils and DNA analyses elucidate the remarkable evolutionary history of whales
Extreme Light
Focusing light with the power of 1,000 Hoover Dams onto a point the size of a cell nucleus accelerates electrons to the speed of light in a femtosecond
Rethinking Green Consumerism
Buying green products won't be enough to save biodiversity in the tropics. A new plan for marketing conservation services may be the answer
Puzzling Adventures: Defense in Depth Avoiding tackles in a football game
Apr 2002
Proteins Rule
Proteomics is biotech's "new new thing." Its enthusiasts are racing to catalogue the proteins in our bodies and to figure out how they network with one another. These efforts could lead to more and better drugs
info tech
Augmented Reality: A New Way of Seeing
Computer scientists are developing systems that can enhance and enrich a user's view of the world
Parasitic Sex Puppeteers
By directing its victims' sex lives, the bacterial parasite Wolbachia may be helping to produce new species
Ripples in Spacetime
Physicists have spent eight years and $365 million building a radically new kind of observatory to detect gravitational waves. But will it work? A trial run put it to the test
The Science of Bad Breath
The age-old condition of bad breath is coming under new scientific scrutiny, leading to insights into diagnostic approaches and possible solutions
The Social Psychology of Modern Slavery
Contrary to conventional wisdom, slavery has not disappeared from the world. Social scientists are trying to explain its persistence
Puzzling Adventures: A Fairy Tale A tale of fairies and pearls
Working Knowledge: Grow, Then Kill Lab tests
Technicalities: Bringing the Net to the Bedroom Even an amateur can create a custom-designed internet appliance
Mar 2002
info tech
The Worldwide Computer
An operating system spanning the Internet would bring the power of millions of the world's Internet-connected PCs to everyone's fingertips
Attacking Anthrax
Recent discoveries are suggesting much-needed strategies for improving prevention and treatment. High on the list: ways to neutralize the anthrax bacterium's fiendish toxin
The Cosmic Reality Check
A celestial audit suggests that astronomers' inventory of luminous bodies may soon be complete
Scars That Won't Heal: The Neurobiology of Child Abuse
Maltreatment at an early age can have enduring negative effects on a child's brain development and function
earth science
Repeated Blows
Did extraterrestrial collisions capable of causing widespread extinctions pound the earth not once, but twice - or even several times?
How Should Reading be Taught?
Educators have long argued over the best way to teach reading to children. The research, however, indicates that a highly popular method is inadequate on its own
Working Knowledge: Secret of Spin Combination locks
Puzzling Adventures: Card Counters Card counting with Bob and Alice
Feb 2002
info tech
The Network in Every Room
Thanks to ingenious engineering, computers and appliances can now communicate through the electrical wiring in a house
The Magic of Microarrays
Research tools known as DNA microarrays are already clarifying the molecular roots of health and disease and speeding drug discovery. They could also hasten the day when custom-tailored treatment plans replace a one-size-fits-all approach to health care
Madagascar's Mesozoic Secrets
The world's fourth-largest island divulges fossils that could revolutionize scientific views on the origins of dinosaurs and mammals
Bejeweled Worlds
What an impoverished universe it would be if Saturn and the other giant planets lacked rings. Planetary scientists are finally working out how gravity has sculpted these elegant ornaments
Television Addiction
Understanding how closely compulsive TV viewing resembles other forms of addiction may help couch potatoes control their habit
The Bottleneck
We have entered the Century of the Environment, in which the immediate future is usefully conceived as a bottleneck: science and technology, combined with foresight and moral courage, must see us through it and out
Working Knowledge: Eye in the Sky Aerial and satellite imaging
Technicalities: Surrounded by Sound Ingenious software makes ordinary stereo speakers come alive
Puzzling Adventures: Shifty Witnesses Skipping the preliminaries, the detective stated his problem: "We have five witnesses whom we don't trust. They have trailed a group of 10 suspected drug dealers. For each suspect, the five witnesses take a vote about whether the suspect has drugs or not.
Jan 2002
The Gas between the Stars
Filled with colossal fountains of hot gas and vast bubbles blown by exploding stars, the interstellar medium is far more interesting than scientists once thought
The First Human Cloned Embryo
Cloned early-stage human embryos - and human embryos generated only from eggs, in a process called parthenogenesis - now put therapeutic cloning within reach
info tech
A Vertical Leap for Microchips
Engineers have discovered a way to pack more computing power into microcircuits: build them vertically as well as horizontally
Misleading Math about the Earth
Science defends itself against The Skeptical Environmentalist
Next-Generation Nuclear Power
New, safer and more economical nuclear reactors could not only satisfy many of our future energy needs but could combat global warming as well
The Economics of Fair Play
Why do we value fairness and cooperation over seemingly more rational selfishness? How can Darwinian generosity arise? Biologists and economists explain
Working Knowledge: Breathing Easier? Gas masks
Puzzling Adventures: Pinpointing a Polar Bear How many hunters does it take to catch a polar bear?
Dec 2001
Vessels of Death or Life
Angiogenesis - the formation of new blood vessels - might one day be manipulated to treat disorders from cancer to heart disease. First-generation drugs are now in the final phase of human testing
Photonic Crystals: Semiconductors of Light
Nanostructured materials containing ordered arrays of holes could lead to an optoelectronics revolution, doing for light what silicon did for electrons
How We Came to Be Human
The acquisition of language and the capacity for symbolic art may lie at the very heart of the extraordinary cognitive abilities that set us apart from the rest of creation
The First Stars in the Universe
Exceptionally massive and bright, the earliest stars changed the course of cosmic history
India, Pakistan and the Bomb
The Indian subcontinent is the most likely place in the world for a nuclear war
info tech
Origins of Personal Computing
Forget Gates, Jobs and Wozniak. The foundations of modern interactive computers were laid decades earlier
Working Knowledge: In the Fast Lane Electronic toll collection
Technicalities: Long-Distance Robots The technology of telepresence makes the world even smaller
Puzzling Adventures: Fashion Gang Fashionable mathematics
Nov 2001
On the Termination of Species
Ecologists' warnings of an ongoing mass extinction are being challenged by skeptics and largely ignored by politicians. In part that is because it is surprisingly hard to know the dimensions of the die-off, why it matters and how it can best be stopped
info tech
The Electronic Paper Chase
Digital "paper" that displays changing text and graphics would ideally marry the best features of traditional printed materials with those of video screens. Companies are racing to realize that promise using two competing technologies. Already retailers are testing cost-saving changeable e-ink signage. Pliable, updatable e-newspapers, e-books and even an e-Scientific American could be here within a decade
Beyond Chicken Soup
The antiviral era is upon us, with an array of virus-fighting drugs on the market and in development. Research into viral genomes is fueling much of this progress
Gravity's Kaleidoscope
The most massive telescopes known to humanity sit not on earthly mountaintops but in deep space. They are gravitational lenses, once mere curiosities, now one of the most important tools in astronomy
The Evolution of Human Birth
The difficulties of childbirth have probably challenged humans and their ancestors for millions of years - which means that the modern custom of seeking assistance during delivery may have similarly ancient roots
Does Class Size Matter?
Legislators are spending billions to reduce class sizes. Will the results by worth the expense?
Working Knowledge: Current Safety Ground fault circuit interrupters
Puzzling Adventures: Truck Stop Mathematics of a truckers' stike
Oct 2001
Magic Bullets Fly Again
Molecular guided missiles called monoclonal antibodies were poised to shoot down cancer and a host of other diseases - until they crashed and burned. Now a new generation is soaring to market
info tech
Code Red for the Web
Could the Internet crash? This summer's Code Red attacks could foreshadow destructive cyberwarfare between hacker groups or between governments
info tech
Driving the Info Highway
The Internet has hit the road. Drivers can now access anything from custom traffic reports to spoken e-mail messages to video games. But is it safe?
astrobiology, life science
Refuges for Life in a Hostile Universe
Only part of our galaxy is fit for advanced life
The Challenge of Macular Degeneration
Researchers have begun to identify the causes of this dreaded eye disease that targets the elderly
Drowning New Orleans
A major hurricane could swamp New Orleans under 20 feet of water, killing thousands. Human activities along the Mississippi River have dramatically increased the risk, and now only massive reengineering of southeastern Louisiana can save the city
Working Knowledge: Mice and Men Computer mouse
Technicalities: A Wide Web of Worlds New Internet browsers add an extra dimension - but little depth
Puzzling Adventures: Crowns of the Minotaur Labyrinthine logic
Sep 2001
Little Big Science
Nanotechnology is all the rage. But will it meet its ambitious goals? And what the heck is it?
Nanofabrication: The Art of Building Small
Researchers are discovering cheap, efficient ways to make structures only a few billionths of a meter across
Nanophysics: Plenty of Room, Indeed
There is plenty of room for practical innovation at the nanoscale. But first, scientists have to understand the unique physics that governs matter there
Nanoelectronics: The Incredible Shrinking Circuit
Researchers have built nanotransistors and nanowires. Now they just need to find a way to put them all together
Nanomedicine: Less is More in Medicine
Sophisticated forms of nanotechnology will find some of their first real-world applications in biomedical research, disease diagnosis and, possibly, therapy
Nanovisions: Machine-Phase Nanotechnology
A molecular nanotechnology pioneer predicts that the tiniest robots will revolutionize manufacturing and transform society
Nanofallacies: Of Chemistry, Love and Nanobots
How soon will we see the nanometer-scale robots envisaged by K. Eric Drexler and other molecular nanotechnologists? The simple answer is never
Nanoinspirations: The Once and Future Nanomachine
Biology outmatches futurists' most elaborate fantasies for molecular robots
Nanorobotics: Nanobot Construction Crews
Nanotechnology visionaries find out how difficult it is to develop minuscule robots that can treat diseases or perform pollution-free manufacturing
Nanofiction: Shamans of Small
Like interstellar travel, time machines and cyberspace, nanotechnology has become one of the core pilot devices on which science-fiction writers draw
Working Knowledge: Flea Treatments Killer drops
Puzzling Adventures: Square Dancing Square dancing without collisions
Aug 2001
info tech
Go Forth and Replicate
Birds do it, bees do it, but could machines do it? New computer simulations suggest that the answer is yes
The Ice of Life
Ice in its earthly guise is hostile to living things. But an exotic form of space ice can actually promote the creation of organic molecules -and may have seeded life on Earth
Cybernetic Cells
The simplest living cell is so complex that supercomputer models may never simulate its behavior perfectly. But even imperfect models could shake the foundations of biology
Once Were Cannibals
Clear evidence of cannibalism in the human fossil record has been rare, but it is now becoming apparent that the practice is deeply rooted in our history
Taming the Killing Fields of Laos
Live bombs from the Vietnam War continue to kill people and hamper agricultural development in Laos. The cleanup project required deciphering decades-old computer files
info tech
The Do-It-Yourself Supercomputer
Scientists have found a cheaper way to solve tremendously difficult computational problems: connect ordinary PCs so that they can work together
The Trouble with Turtles
Despite heroic efforts to protect the nesting beaches of green turtles, fewer and fewer of these endangered creatures reappear every year. Researchers have been stunned to discover that shielding young turtles is only half the battle
Working Knowledge: Crank It Up! Human-powered electronics
Technicalities: Touchy-Feely Computing A new mouse picks up good vibrations
Puzzling Adventures: The Delphi Flip Predicting the future accurately is most useful in betting games - the stock market comes to mind
Jul 2001
info tech
How to Build a Hypercomputer
The simulation and ultimate solution of humanity's major ills and most perplexing problems require significantly faster supercomputers
The Truth and Hype of Hypnosis
Though often denigrated as fakery or wishful thinking, hypnosis has been shown to be a real phenomenon with a variety of therapeutic uses - especially in controlling pain
Making Molecules into Motors
Molecular turmoil, quantum craziness: microscopic machines must operate in a world gone mad. But if you can't beat the chaos, why not exploit it?
Frozen Light
Slowing a beam of light to a halt may pave the way for new optical communications technology, tabletop black holes and quantum computers
Battling Biofilms
The war is against bacterial colonies that cause some of the most tenacious infections known. The weapon is knowledge of the enemy's communication system
Fishy Business
Cyanide fishing threatens many of the last pristine coral reefs in Southeast Asia. Will an ambitious program to clean up the marine aquarium trade be enough to save them?
Working Knowledge: Tan or Burn Protecting skin from the summer sun
Puzzling Adventures: Seeing Red, Feeling Blue Here's a puzzle full of clashing colors
Jun 2001
The Paradox of the Sun's Hot Corona
Like a boiling teakettle atop a cold stove, the sun's hot outer layers sit on the relatively cool surface. And now astronomers are figuring out why
Solving the Mystery of Insect Flight
Insects use a combination of aerodynamic effects to remain aloft
Sign Language in the Brain
How does the human brain process language? New studies of deaf signers hint at an answer
space science
North to Mars!
To pave the way for a mission to Mars, a band of scientists decided to go to the Canadian arctic
Hair - Why It Grows Why It Stops
Scientists are rapidly discovering the molecules that control hair production. In so doing, they could be unearthing the key to combating both baldness and excessive hair growth
The Himba and the Dam
A questionable act of progress may drown this African tribe's way of life. Similar dramas are playing out around the world
A Low-pollution Engine Solution
Clean-burning, sparkless-ignition auto engines may offer the best chance of meeting new exhaust emissions standards
Working Knowledge: Flight Control Golf balls
Technicalities: Kibbles and Bytes How much is that robotic doggy in the window?
Puzzling Adventures: Alternating Liars Liar, liar, liar
May 2001
info tech
The Semantic Web
A new form of Web content that is meaningful to computers will unleash a revolution of new possibilities
Rip Van Twinkle
The oldest stars have been growing younger
Behind Enemy Lines
A close look at the inner workings of microbes in the era of escalating antibiotic resistance is offering new strategies for designing drugs
The Arctic Oil and Wildlife Refuge
The last great onshore oil field in America may lie beneath the nation's last great coastal wilderness preserve. Science can clarify the potential economic benefits and the ecological risks of drilling into it
Warp Drive Underwater
Traveling inside drag-cutting bubbles, secret torpedoes and other subsea naval systems can move hundreds of miles per hour
What's Wrong with This Picture?
Psychologists often use the famous Rorschach inkblot test and related tools to assess personality and mental illness. But research says the instruments are frequently ineffective for those purposes
Working Knowledge: Quick Scan Bar-code readers
Puzzling Adventures: Something Fishy Retracing a villain's steps
Apr 2001
Whose Blood Is It, Anyway?
Blood collected from umbilical cords and placentas - which are usually thrown away following birth - contains stem cells that can rebuild the blood and immune systems of people with leukemia and other cancers
Genetically Modified Foods: Are They Safe? - Introduction
A look at how much science really knows about the risks of growing and eating genetically modified crops.
Genetically Modified Foods: Are They Safe? - Seeds of Concern
Are genetically modified crops an environmental dream come true or a disaster in the making? Scientists are looking for answers
Genetically Modified Foods: Are They Safe? - The Risks on the Table
More than half the foods in U.S. supermarkets contain genetically modified ingredients. Have they been proved safe for human consumption?
Genetically Modified Foods: Are They Safe? - Does the World Need GM Foods? (Q&A)
Two leading figures in the debate over genetic engineering defend their stances
info tech
Virtually There
Three-dimensional tele-immersion may eventually bring the world to your desk
Life's Rocky Start
Air, water and rock were the only raw materials available on the early earth. The first living entitities must been fabricated from these primitive resources. New experiments suggest that minerals - the basic components of the rocks - could have played starring roles in that dramatic feat
The Fury of Space Storms
Shock waves from the sun can trigger severe turbulence in the space around the earth, endangering satellites and astronauts in orbit. Now a new spacecraft is showing how space storms develop
Violent Pride
Do people turn violent because of self-hate, or self-love?
Working Knowledge: Touch Screens - At Your Fingertips A truly touchy interface
Technicalities: Look, Ma, No Wires! The Ricochet wireless modem is like a Ferrari - fast but pricey
Puzzling Adventures: No Tipping A weighty search for leverage
Mar 2001
Making Sense of Taste
How do cells on the tongue register the sensations of sweet, salty, sour and bitter? Scientists are finding out - and discovering how the brain interprets these signals as various tastes
earth science
Sculpting the Earth from Inside Out
Powerful motions deep inside the planet do not merely shove fragments of the rocky shell horizontally around the globe - they also lift and lower entire continents
If Humans Were Built to Last
We would look a lot different - inside and out - if evolution had designed the human body to function smoothly not only in youth but for a century or more
A Sharper View of the Stars
A new generation of optical interferometers is letting astronomers study stars in 100 times finer detail than is possible with the Hubble Space Telescope
Evolution: A Lizard's Tale
On some islands in the Caribbean, evolution seems to have taken the same turn - over and over and over again
The Geography of Poverty and Wealth
Tropical climate and lack of access to sea trade have hurt the poorest nations. But new aid programs point the way to prosperity
Working Knowledge: Gotcha! How radar guns catch speeders
The Amateur Scientist: Geotropism, One Last Time How plants grow in reduced gravity
Mathematical Recreations: Easter Is a Quasicrystal The divine mathematics of a holiday
Feb 2001
Special Report: Safeguarding Our Water/Introduction
Drip, trickle, splash. Water is one of the most common substances in the universe, and our ocean-wrapped planet is blessed with a generous share of it. Unfortunately, 97 percent of that share is salty, and much of the rest is locked up in ice.
Special Report: Safeguarding Our Water/Making Every Drop Count
We drink it, we generate electricity with it, we soak our crops with it. And we're stretching our supplies to the breaking point. Will we have enough clean water to satisfy all the world's needs?
Special Report: Safeguarding Our Water/Growing More Food with Less Water
If the world hopes to feed its burgeoning population, irrigation must become less wasteful and more widespread
Special Report: Safeguarding Our Water/How We Can Do It
A look at four promising ways to maintain adequate supplies of freshwater: desalination, new technologies for transporting water, reducing demand, and recycling
Why the Y is So Weird
Our X and Y chromosomes make an odd couple. The X resembles any other chromosome, but the Y - the source of maleness - is downright strange. How did the two come to differ so much?
In Pursuit of the Ultimate Lamp
Full-spectrum light-emitting diodes, or LEDs, are becoming widespread - and the race is on to develop white-light versions to replace Edison's century-old incandescent bulb
100 Years of Quantum Mysteries
As quantum theory celebrates its 100th birthday, spectacular successes are mixed with persistent puzzles
The Science of Persuasion
Salespeople, politicians, friends and family all have a stake in getting you to agree to their requests. Social psychology has determined the basic principles that govern getting to "yes"
Working Knowledge: Preparing for Battle How vaccines prevent the flu
The Amateur Scientist: Counting Particles from Space How to build a cosmic-ray telescope
Mathematical Recreations: Pursuing Polygonal Privacy Good fences make good neighbors
Jan 2001
Brave New Cosmos: Introduction
Observational cosmology is about to become a mature science. Explanations for the universe's unexpectedly odd behaviors may then be around the corner
Brave New Cosmos: Echoes from the Big Bang
Scientists may soon glimpse the universe's beginnings by studying the subtle ripples made by gravitational waves
Brave New Cosmos: A Cosmic Cartographer
The Microwave Anisotropy Probe will give cosmologists a much sharper picture of the early universe
Brave New Cosmos: The Quintessential Universe
The universe has recently been commandeered by an invisible energy field, which is causing its expansion to accelerate outward
Brave New Cosmos: Making Sense of Modern Cosmology
Confused by all those theories? Good
Brave New Cosmos: Plan B for the Cosmos
If the new cosmology fails, what's the backup plan?
The Cultures of Chimpanzees
Humankind's nearest relative is even closer than we thought: chimpanzees display remarkable behaviors that can only be described as social customs passed on from generation to generation
The Cellular Chamber of Doom
Structures called proteasomes inside cells continously destroy proteins. Several common diseases result when the process works too zealously - or not at all
The Mystery of Damascus Blades
Centuries ago craftsmen forged peerless steel blades. But how did they do it? The author and a blacksmith have found the answer
info tech
The Triumph of the Light
Extensions to fiber optics will supply network capacity that borders on the infinite
info tech
The Rise of Optical Switching
Replacing electronic switches with purely optical ones will become the technological linchpin for networks that transmit trillions of bits each second
info tech
Routing Packets with Light
The ultimate all-optical network will require dramatic advances in technologies that use one lightwave to imprint information on another
Working Knowledge: The Well-Rounded Flat Speaker The rounded tones of flat-panel speakers
Mathematical Recreations: Dots-and-Boxes for Experts The secret subtleties of a children's game
The Amateur Scientist: A Canteen Cloud Chamber Viewing the path of charged particles
Dec 2000
Rulers of the Jurassic Seas
Fish-shaped reptiles called ichthyosaurs reigned over the oceans for as long as dinosaurs roamed the land, but only recently have paleontologists discovered why these creatures were so successful
Nanotubes for Electronics
They are stronger than steel, but the most important uses for these threadlike macromolecules may be in faster, more efficient and more durable electronic devices
The Secrets of Stardust
Tiny grains of dust floating in interstellar space have radically altered the history of our galaxy
Piecing Together Alzheimer?s
The stunningly complex biochemical puzzle that underlies this crippling disease remains incomplete, but parts that seemed unrelated just a decade ago are now fitting into place
urban planning
The Science of Smart Growth
Are there any alternatives to urban sprawl? Pundits and pols may endlessly debate that question, but the only way to get an answer is to go out and see what works in the real world
The Coolest Gas in the Universe
Bose-Einstein condensates are one of the hottest areas in experimental physics
Working Knowledge: Superabsorbers Disposable diapers
The Amateur Scientist: Calibrating with Cold How to fine-tune a laboratory thermometer
Mathematical Recreations: Jumping Champions Counting the gaps between primes
Nov 2000
consumer electronics
Special Report: The Future of Digital Entertainment/Introduction
The barriers separating TV, movies, music, video games and the Internet are crumbling. Audiences are getting new creative options. Here is what entertainment could become if the technological and legal hurdles can be cleared.
consumer electronics
Special Report: The Future of Digital Entertainment/Creating Convergence
TV, movies, Internet video, and music could morph into one big stream of d-entertainment that we can enjoy on any device, anywhere, anytime. But the devil is in the details
consumer electronics
Special Report: The Future of Digital Entertainment/Music Wars
Internet distribution of quality d-audio is rapidly being perfected, but the precedent-setting legal battles have just begun
consumer electronics
Special Report: The Future of Digital Entertainment/Moviemaking in Transition
Digital video cameras and editing equipment are transforming the way movies are made - even which movies get made
consumer electronics
Special Report: The Future of Digital Entertainment/Digital Cinema Is for Reel
Digital projection works,but it's not at a theater near you - yet
consumer electronics
Special Report: The Future of Digital Entertainment/Digital Humans Wait in the Wings
Characters, scenes and entire movies have been crafted digitally. But can animators create realistic humans to star in computer-generated films? Actors want to know
consumer electronics
Special Report: The Future of Digital Entertainment/Your Own Virtual Storyworld
True interactive entertainment will arise once engineers and artists create virtual realities that can unfold improvisationally
Cloning Noah's Ark
Biotechnology might offer the best way to keep some endangered species from disappearing from the planet
space science
The Vasimir Rocket
There used to be two types of rocket: powerful but fuel-guzzling, or efficient but weak. Now there is a third option that combines the advantages of both
AIDS Drugs for Africa
Most of the 35 million people infected with the AIDS virus live on the African continent, where drugs that fight the virus are rare. Will the world let them die?
The Odd Couple and the Bomb
Like a story by Victor Hugo as told to Neil Simon, the events leading up to the first controlled nuclear chain reaction involved accidental encounters among larger-than-life figures, especially two who did not exactly get along ? but had to
Working Knowledge: Pregnancy Tests How home pregnancy tests work.
The Amateur Scientist: Boids of a Feather Flock Together Simulating boids, floys and other artificial life.
Mathematical Recreations: Spiral Slime How nature draws spirals and shapes.
Oct 2000
info tech
The Wireless Web: Special Report/Introduction
The Internet has been the subject of more self-parodying hype than anything since 500-channel cable.
info tech
The Wireless Web: Special Report/The Internet in Your Hands
To spur the growth of the wireless Web, companies are developing networks that can handle huge amounts of data and handheld devices that can tap into all the Internet's resources
info tech
The Wireless Web: Special Report/The Promise and Perils of WAP
The Wireless Application Protocol allows cell phone users to connect to the Internet, but the technology has serious limitations
info tech
The Wireless Web: Special Report/The Future is Here. Or Is It?
How will Web phones ever become popular if it takes 10 minutes and costs $4 to send one e-mail?
info tech
The Wireless Web: Special Report/The Third-Generation Gap
A revolution needs a plan. Which technology will provide it?
Operating on a Beating Heart
Coronary bypass surgery can be a lifesaving operation. Two new surgical techniques should make the procedure safer and less expensive
life science
The Power of Memes
Behaviors and ideas copied from person to person by imitation - memes - may have forced human genes to make us what we are today
Nabada: The Buried City
Excavations in northern Syria reveal the metropolis of Nabada, founded 4,500 years ago. Its elaborate administration and culture rivaled those of the fabled cities of southern Mesopotamia
Better Decisions through Science
Math-based aids for making decisions in medicine and industry could improve many diagnoses - often saving lives in the process
Working Knowledge: The Hard and the Soft Contact lenses: something in your eye?
The Amateur Scientist: Down among the Micrograms High-precision scales bring balance to home labs.
Mathematical Recreations: Million-Dollar Minesweeper How a computer game can make you rich
Sep 2000
Muscle, Genes and Athletic Performance
The cellular biology of muscle helps to explain why a particular athlete wins and suggests what future athletes might do to better their odds
Searching for Shadows of Other Earths
Astronomers have found dozens of giant planets beyond our solar system, but they haven't been capable of bagging an Earth - until now
Edible Vaccines
One day children may get immunized by munching on foods instead of enduring shots. More important, food vaccines might save millions who now die for lack of access to traditional inoculants
Ultrashort-Pulse Lasers: Big Payoffs in a Flash
The briefest man-made events, pulses of laser light lasting millionths of a nanosecond, can be used for delicate eye surgery, high-bandwidth communications and stop-motion studies of molecules reacting
Who Were the First Americans?
If your answer was fur-clad mammoth hunters, guess again. The first people to settle the New World may have been fisherfolk and basket weavers
The Plan to Save Fallingwater
This breathtaking house designed by Frank Lloyd Wright was in danger of collapse until an engineering firm found a way to stop it from falling down
Working Knowledge: A Better Black Box How do black boxes survive plane crashes?
The Amateur Scientist: Using a Kite as an Experimental Platform Kites carry eyes in the sky
Mathematical Recreations: Hex Marks the Spot The mind-bending challenge of Hex.
Aug 2000
materials science
How Green Are Green Plastics?
It is now technologically possible to make plastics using green plants rather than nonrenewable fossil fuels. But are these new plastics the environmental saviors researchers have hoped for?
Fountains of Youth: Early Days in the Life of a Star
To make a star, gas and dust must fall inward. So why do astronomers see stuff streaming outward?
climate change
Is Global Warming Harmful to Health?
Computer models indicate that many diseases will surge as the earth's atmosphere heats up. Signs of the predicted troubles have begun to appear
Form from Fire
Self-propagating heat waves can engender new and improved materials, but only recently have researchers found ways to monitor these ultraquick chemical reactions
The Universe's Unseen Dimensions
The visible universe could lie on a membrane floating within a higher-dimensional space. The extra dimensions would help unify the forces of nature and could contain parallel universes
Male Sexual Circuitry
The brain is the most important sex organ. One of its roles in male sexuality is to keep the penis under control.
Birth of the Modern Diet
Ever wonder why dessert is served after dinner? The origins of modern Western cooking can be traced to ideas about diet and nutrition that arose during the 17th century
Working Knowledge: Focusing in a Flash Cheese! How cameras autofocus
The Amateur Scientist: How to Rear a Plankton Menagerie Raising a plankton menagerie.
Mathematical Recreations: A Fractal Guide to Tic-Tac-Toe A familiar shape in unexpected places
Jul 2000
life science
Special Industry Report: The Business of the Human Genome (Introduction)
The task of sequencing all human DNA is all but done, but mining the mountains of genetic information for pay dirt is just beginning
life science
Special Industry Report: The Human Genome Business Today
It's been a wild ride for the corporate and government parties who have deciphered the human genetic code. The fun has just begun
life science
Special Industry Report: The Bioinformatics Gold Rush
A $300-million industry has emerged around turning raw genome data into knowledge for making new drugs
life science
Special Industry Report: Beyond the Human Genome
With all of the DNA that codes for a human in hand, the challenge then becomes what to make of it. Some of the first fruits will come from a new field called proteomics
The Large Hadron Collider
The Large Hadron Collider will be a particle accelerator of unprecedented energy and complexity, a global collaboration to uncover an exotic new layer of reality
Darwin's Influence on Modern Thought
Great minds shape the thinking of successive historical periods. Luther and Calvin inspired the Reformation; Locke, Leibnitz, Voltaire and Rousseau, the Enlightenment. Modern thought is most dependent on the influence of Charles Darwin
The Revolutionary Bridges of Robert Maillart
Swiss engineer Robert Maillart built some of the greatest bridges of the 20th century. His designs elegantly solved a basic engineering problem: how to support enormous weights using a slender arch
earth science
The Killing Lakes
Two lakes in Cameroon are poised to release lethal gas, as they did in the 1980s. Writer Marguerite Holloway reports on scientists' efforts to prevent another tragedy
Working Knowledge: Escape and Survival With luck, the unnecessary space suit.
The Amateur Scientist: PCR at Home Copying DNA in your kitchen.
Mathematical Recreations: Knotting Ventured... How pieces of string can illustrate the principles of symmetry
Jun 2000
Special Report: Waging a New Kind of War (Introduction)
What could possibly be new about war? People have always been quite imaginative about finding ways to impose their will by violent force. Rocks and spears, catapults and muskets, mustard gas and nukes: you might think that human civilization has tried it all. Evidently not.
Special Report: A Scourge of Small Arms
With a few hundred machine guns and mortars, a small army can take over an entire country, killing and wounding hundreds of thousands
Special Report: Invisible Wounds
Medical researchers have recently begun to address the mental health effects of war on civilians
Special Report: Children of the Gun
How do you make a child into a killer? Armed groups worldwide have developed a grim routine: abduct children from their families, inure them to abuse and "promote" them into combat
Dwarf Galaxies and Starbursts
Diminutive galaxies occasionally experience spectacular bursts of star formation. These starbursts are giving astronomers a glimpse of the universe's early history
Cell Communication: The Inside Story
The tiny cells in our bodies harbor amazing internal communication networks. Understanding how those circuits are organized could help scientists develop new therapies for many serious disorders
Reading the Bones of La Florida
New approaches are offering insight into the lives of Native Americans after the Europeans arrived. Their health declined not only because of disease but because of their altered diet and living circumstances
Computing with Molecules
Researchers have produced molecules that act like switches, wires and even memory elements. But connecting many of the devices together presents enormous challenges
Looking for Life Below the Bottom
Two scientists have a hunch that the largest repository of life is not the oceans but the fractured rock beneath them. Staff writer Sarah Simpson recounts the voyage to find proof
May 2000
The Small Planets
Asteroids have become notorious as celestial menaces but are best appreciated in a positive light, as surreal worlds bearing testimony to the origin of the planets
info tech
Special Industry Report: Avoiding A Data Crunch
The technology of computer hard drives is fast approaching a physical barrier imposed by the superparamagnetic effect. Overcoming it will require tricky innovations
Coping with Crowding
A persistent and popular view holds that high population density inevitably leads to violence. This myth, which is based on rat research, applies neither to us nor to other primates
Making Metallic Hydrogen
By re-creating extreme conditions like those in Jupiter's core, physicists have at long last turned hydrogen into a metal
Care for a Dying Continent
In Zimbabwe - where AIDS is prematurely killing a generation of adults - counselors and researchers struggle against social customs, viral resourcefulness and despair
Apr 2000
Quantum Teleportation
The science-fiction dream of "beaming" objects from place to place is now a reality - at least for particles of light
Building a Brainier Mouse
By genetically engineering a smarter than average mouse, scientists have assembled some of the central molecular components of learning and memory
Understanding Clinical Trials
The journey from initial medical research to the bottle in your family's medicine cabinet is complex, time-consuming and expensive. Can the clinical trial process be refined?
The Discovery of Brown Dwarfs
Less massive than stars but more massive than planets, brown dwarfs were long assumed to be rare. New sky surveys, however, show that the objects may be as common as stars
The Aleutian Kayak
The Aleuts built the baidarka to suit their life as hunters on the open ocean. The sophisticated design of this kayak is still not entirely understood
Monitoring Earth's Vital Signs
A new NASA satellite - one of a fleet called the Earth Observing System - is using five state-of-the-art sensors to diagnose the planet's health like never before
Who Were the Neandertals?
Controversial evidence indicates that these hominids interbred with anatomically modern humans and sometimes behaved in surprisingly modern ways
Mar 2000
space science
Why Go to Mars?
In the first of this group of articles about human missions to Mars, staff writer Glenn Zorpette examines the main goal: looking for life
space science
How to Go to Mars?
Staff writers George Musser and Mark Alpert make sense of the myriad ideas for a human mission
space science
The Mars Direct Plan
A leading advocate of manned missions to Mars, Robert Zubrin, outlines his relatively inexpensive plan to send astronauts to the Red Planet within a decade
space science
To Mars By Way of its Moons
Phobos and Deimos would make ideal staging areas, argues veteran space scientist S. Fred Singer
space science
A Bus Between the Planets
Gravity-assist trajectories between Earth and Mars would reduce the cost of shuttling human crews and their equipment, say James Oberg and Buzz Aldrin
space science
Staying Sane in Space
Is the "right stuff" enough? asks staff writer Sarah Simpson
space science
Invaders from Hollywood
Thanks to Pathfinder and other missions, science gets some respect in Tinseltown, as staff writer Philip Yam finds after touchdown on a Vancouver set
The Tick-Tock of the Biological clock
Biological clocks count off 24-hour intervals in most forms of life. Genetics has revealed that related molecular timepieces are at work in fruit flies, mice and humans
Swarm Smarts
Using ants and other social insects as models, computer scientists have created software agents that cooperate to solve complex problems, such as the rerouting of traffic in a busy telecom network
Dissecting a Hurricane
Flying into the raging tumult of Dennis, scientists suspected that the storm might transform into a monster - if they were lucky
The Bromeliads of the Atlantic Forest
Along the coast of Brazil, 8 percent of a once flourishing forest is left to house a diverse family of bromeliads. A group of biologists scale cliffs and trees to collect these rare beauties
Feb 2000
The Galileo Mission to Jupiter and Its Moons
Few scientists thought that the Galileo spacecraft, beset by technical troubles, could conduct such a comprehensive study of the Jovian system. And few predicted that the innards of these worlds would prove so varied
materials science
Melting Below Zero
New research shows how a layer of water on the surface of ice - even at temperatures well below freezing - can influence everything from the slipperiness of a skating rink to the electrification of thunderclouds
The Early Origins of Autism
New research into the causes of this baffling disorder is focusing on genes that control the development of the brain
info tech
Digital Materials and Virtual Weathering
The next step in creating more realistic computer-generated images is the development of better models of the physical structures of materials and their degradation by the environment
climate change
Capturing Greenhouse Gases
Sequestering carbon dioxide underground or in the deep ocean could help alleviate concerns about climate change
Transparent Animals
Ingenious physiological accommodations have evolved to enable a stunning variety of undersea creatures to be remarkably transparent
Uprooting the Tree of Life
About 10 years ago scientists finally worked out the basic outline of how modern life-forms evolved. Now parts of their tidy scheme are unraveling
Jan 2000
Negative Energy, Wormholes and Warp Drive
The construction of wormholes and warp drive would require a very unusual form of energy. Unfortunately, the same laws of physics that allow the existence of this "negative energy" also appear to limit its behavior
Once We Were Not Alone
Today we take for granted that Homo Sapiens is the only hominid on Earth. Yet for at least four million years many hominid species shared the planet. What makes us different?
Voyage to SUPERHEAVY Island
The synthesis of element 114 confirmed decades-old theoretical predictions of a little patch of nuclear stability in a sea of short-lived superheavy nuclei
earth science
Snowball Earth
Ice entombed our planet hundreds of millions of years ago, and complex animals evolved in the greenhouse heat wave that followed
Although people with the disorder do not fall face-first into their soup as in the movies, narcolepsy is still a mysterious disease. But science has new leads
Maglev: A New Approach
The Inductrack promises a safer, cheaper system for magnetically levitating trains. The same technology can also be used to launch rockets
public health
The Unmet Need for Family Planning
Women and men in many countries still lack adequate access to contraceptives. Unless they are given the option of controlling their fertility, severe environmental and health problems loom in the coming century throughout large parts of the world
The Amateur Scientist Detecting Extraterrestrial Gravity
Mathematical Recreations Impossibility Theorems
Dec 1999
The Unexpected Science to Come The most important discoveries of the next 50 years are likely to be ones of which we cannot now even conceive
A Unified Physics by 2050? Experiments at CERN and elsewhere should let us complete the Standard Model of particle physics, but a unified theory of all forces will probably require radically new ideas
Exploring Our Universe and Others In the 21st century cosmologists will unravel the mystery of our universe's birth - and perhaps prove the existence of other universes as well
Deciphering the Code of Life The study of all the genes of various organisms will yield answers to some of the most intriguing questions about life
The End of Nature versus Nurture Is human behavior determined by genetics or by environment? It may be time to abandon the dichotomy
The Human Impact on Climate How much of a disruption do we cause? The much-awaited answer could be ours by 2050, but only if nations of the world commit to long-term monitoring now
Can Human Aging Be Postponed? In theory, it certainly can. Yet no single elixir will do the trick. Antiaging therapies of the future will undoubtedly have to counter many destructive biochemical processes at once
How the Brain Creates the Mind Philosophers, neuroscientists and laypeople have long wondered how the conscious mind comes to be. A more complete understanding of the workings of the brain ought to lead to an eventual solution
Is There Life Elsewhere in the Universe? The answer is: nobody knows. Scientists' search for life beyond Earth has been less thorough than commonly thought. But that is about to change
Rise of the Robots By 2050 robot "brains" based on computers that execute 100 trillion instructions per second will start rivaling human intelligence
Mathematical Recreations Defend the Roman Empire!
Nov 1999
The Fate of Life in the Universe Billions of years ago the universe was too hot for life to exist. Countless eons hence, it will become so cold and empty that life, no matter how ingenious, will perish
Vision: A Window on Consciousness In their search for the mind, scientists are focusing on visual perception - how we interpret what we see
Flammable Ice Methane-laced ice crystals in the seafloor store more energy than all the world's fossil fuel reserves combined. But these methane hydrate deposits are fragile, and the gas that escapes from them may exacerbate global warming
Slave-Making Queens Life in certain corners of the ant world is fraught with invasion, murder and hostage-taking. The battle royal is a form of social parasitism
Time-Reversed Acoustics Arrays of transducers can re-create a sound and send it back to its source as if time had been reversed. The process can be used to destroy kidney stones, detect defects in materials and communicate with submarines
Floating in Space Balloons offer scientists a low-cost, quick-response way to study the upper reaches of Earth's atmosphere and those of other planets
A Zeppelin for the 21st Century By developing new aerodynamic computer models and using modern materials, the company that originated zeppelins has returned them to the skies over Europe
The Balloon That Flew round the World To build a balloon capable of circumnavigating the globe, engineers ripped a page from aeronautical history
The Grameen Bank A small experiment begun in Bangladesh has turned into a major new concept in eradicating poverty
The Amateur Scientist Falling into Chaos
Mathematical Recreations Most-Perfect Magic Squares
Oct 1999
The Hidden Ocean of Europa Doodles and freckles, creamy plains and crypto-icebergs - the amazing surface of Jupiter's brightest icy moon hints at a global sea underneath
Why Things Break Scientists have known for most of this century that chemistry is responsible for whether a solid shatters or bends. But only now are they finding a way to predict which type of failure will win
Preserving Nefertari's Legacy The tomb of this ancient Egyptian queen is testament to the great love of Pharaoh Ramses II. Its preservation is testament to advances in conservation
The Unmet Challenges of Hepatitis C Some 1.8 percent of the U.S. adult population are infected with the hepatitis C virus, most without knowing it
The False Crisis in Science Education The largely mythical decline of science in the public schools is leading - yet again - to rushed reforms that ignore the best advice on what kids should know
High-Speed Data Races Home The global network is entering a new phase in its evolution, one that will spawn new applications and make dial-up modems a thing of the past
The Internet via Cable Only cable networks are well equipped to provide hybrid TV-Internet services, as well as superfast on-line access
DSL: Broadband by Phone Alexander Graham Bell's ubiquitous copper wires will still be a capacity-rich communications resource in the third millennium
The Broadest Broadband New technologies promise to reduce the cost of linking homes with optical fiber, the ultimate medium for data communications
Satellites: The Strategic High Ground Data communications systems that use satellites to transmit signals have many advantages over ground-based systems
LMDS: Broadband Wireless Access Ground-based wireless networks delivering the full range of broadband services can be deployed quickly and inexpensively
The Light at the End of the Pipe A much faster and easier-to-use Internet will stimulate the introduction of new services and possibly even significant social metamorphoses
Mathematical Recreations Cone with a Twist
The Amateur Scientist Modeling the Atomic Universe
Sep 1999
Breathing Life into "Tyrannosaurus rex" By analyzing previously overlooked fossils and by taking a second look at some old finds,paleontologists are providing the first glimpses of the actual behavior of the tyrannosaurs
The Teeth of the Tyrannosaurs Their teeth reveal aspects of their hunting and feeding habits
The Dechronization of Sam Magruder "The brute - it was a tyrannosaur - got me by the leg. He shook me loose, tearing off the leg at the knee, and he didn't see where the rest of me fell. I tied up the stump and crawled away...."
Migrating Planets Did the solar system always look the way it does now? New evidence indicates that the outer planets may have migrated to their present orbits
Repairing the Damaged Spinal Cord Once little more than a futile hope, some restoration of the injured spinal cord is beginning to seem feasible
A Case against Virtual Nuclear Testing The U.S. Department of Energy's high-tech plan to replace nuclear testing with elaborate 3-D computer simulations is seriously flawed
The Throat Singers of Tuva Testing the limits of vocal ingenuity, throat-singers can create sounds unlike anything in ordinary speech and song - carrying two musical lines simultaneously, say, or harmonizing with a waterfall
Scientists and Religion in America Science and religion are engaging in more active dialogue and debate, but a survey suggests that scientists' beliefs have changed little since the 1930s, and top scientists are more atheistic than ever before
The Amateur Scientist Counting Atmospheric Ions
Mathematical Recreations Dances with Dodecahedra
Aug 1999
Why National Missile Defense Won't Work The current plan for defending the U.S. against a ballistic-missile attack faces many of the problems that plagued a similar plan three decades ago
The Lurking Perils of "Pfiesteria" This minute creature has been implicated in dramatic fish kills and has hurt people. But its most publicized actions may not be the most damaging. More subtle effects are raising new concerns
The Future of Computing M.I.T.'s Laboratory for Computer Science is developing a new infrastructure for information technologies - the Oxygen system - that promises to realize a vision long held by the lab's director: helping people do more by doing less
Talking with Your Computer Speech-based interfaces may soon allow computer users to retrieve data and issue instructions without lifting a finger
Communications Chameleons Multipurpose communications systems will be the links of tomorrow's wireless computer networks
Raw Computation One of the main engines of the Oxygen project is the Raw microchip, which has wiring that can be automatically reprogrammed for different tasks
Detecting Massive Neutrinos A giant detector in the heart of Mount Ikenoyama in Japan has demonstrated that the neutrino metamorphoses in flight, strongly suggesting that these ghostly particles have mass
The Moral Development of Children It is not enough for kids to tell right from wrong. They must develop a commitment to acting on their ideals. Enlightened parenting can help
Trailing a Virus As a virus never seen before swept through rural Malaysia, killing more than 110 and forcing the destruction of a million swine, it revealed the world's vulnerability to new diseases. Even the best efforts of top scientists are sometimes not enough to thwart them
The Amateur Scientist Sun of a Gun
Mathematical Recreations Sierpinski's Ubiquitous Gasket
Jul 1999
Looking back at Apollo On the 30th anniversary of the first manned lunar landing, digital reproductions of the Apollo photographs show the moon as the astonauts saw it
Life's Far-Flung Raw Materials Life may owe its start to complex organic molecules manufactured in the icy heart of an interstellar cloud
Genetic Vaccines Vaccines crafted from genetic material might one day prevent AIDS, malaria and other devastating infections that defy current immunization technologies. They may even help treat cancer
The Mystery of Nucleon Spin A new generation of experiments promises to pin down more of the still uncertain internal structure of protons and neutrons
The Earliest Zoos and Gardens More than 4,000 years ago rulers in Egypt and Mesopotamia, builders of pyramids and empires, became the first to embark on another pastime: collecting exotic animals and planting ornamental gardens
The Future Of Fuel Cells The obstacles to building practical fuel cells are numerous, but continued innovation and skillful engineering could make them competitive
The Electrochemical Engine for Vehicles Fuel cells can power cleaner buses and cars, but key engineering and economic obstacles will delay widespread adoption of the technology
The Power Plant in Your Basement In the past, stationary fuel cells were megawatt behemoths, designed for the electric utilities. Now they are being shrunk for homes and other modest applications
Replacing the Battery in Portable Electronics Batteries are cumbersome and expensive. Miniature fuel cells could supplant them in cellular phones, laptop computers, camcorders and other consumer products
The Amateur Scientist Detecting the Earth's Electricity
Mathematical Recreations The Art of Elegant Tiling
Jun 1999
Mapping the Universe Using techniques drawn from the analysis of music, astronomers have been studying how galaxies form into progressively larger groupings
How The Body tells Left from Right The precise orientation of our internal organs - and those of all other animals with a backbone - is controlled in part by proteins that are produced on only one side of an embryo
Hypersearching the Web With the volume of on-line information in cyberspace growing at a breakneck pace, more effective search tools are desperately needed. A new technique analyzes how Web pages are linked together
Image-Guided Surgery Virtual-reality technology is giving surgeons the equivalent of x-ray vision, helping them to remove tumors more effectively, to minimize surgical wounds and to avoid damaging critical tissues
Biological Warfare against Crops Intentionally unleashing organisms that kill an enemy's food crops is a potentially devastating weapon of warfare and terrorism
Gödel and the Limits of Logic Mathematical genius Kurt Gödel was devoted to rationality in his work but struggled with it in his personal life
Chasing the Ghost Bat On jungle rivers in Belize, two zoologists catch the ultrasonic cries of bats - and fish for a big one
The Amateur Scientist Expert Secrets for Preserving Plants
Mathematical Recreations Crossed Lines in the Brick Factory
May 1999
Unmasking Black Holes Until recently, the evidence for black holes was circumstantial. Now astronomers may have direct proof: energy is vanishing from volumes of space without a trace
New Nerve Cells for the Adult Brain Contrary to dogma, the human brain does produce new nerve cells in adulthood. Can our newfound capacity lead to better treatments for neurological diseases?
Tsunami! Its awesome fury cannot be diminished, but lessons learned from a rash of disasters this decade - and a new way to track these killer waves - will help save lives
Killer Kangaroos and Other Murderous Marsupials Australian mammals were not all as cute as koalas. Some were as ferocious as they were bizarre
Ada and the First Computer The collaboration between Ada, countess of Lovelace, and computer pioneer Charles Babbage resulted in a landmark publication that described how to program the world's first computer
The Andaman Islanders The aboriginal inhabitants of a stretch of islands near India offer a fascinating glimpse into the way of life of traditional hunter-gatherers. But how long will this window to our past remain open?
XML and the Second-Generation Web The combination of hypertext and a global Internet started a revolution. A new ingredient, XML, is poised to finish the job
The Amateur Scientist Hot Views of the Microscopic World
Mathematical Recreations A Puzzle for Pirates
Apr 1999
Growing New Organs Researchers have taken the first steps toward creating semisynthetic, living organs that can be used as human replacement parts
Embryonic Stem Cells for Medicine Cells able to generate virtually all other cell types have recently been isolated. One day they could help repair a wide variety of damaged tissues
Encapsulated Cells as Therapy An emerging approach to treating disease combines living cells with plastic membranes that shield the cells from immune attack
Skin: The First Tissue-Engineered Products Last year the first living, tissue-engineered skin product became commercially available - and a second is expected to be on the market within a few months. Top researchers from each of the two companies involved tell how their products came to be
Tissue Engineering: The Challenges Ahead The obstacles to building new organs from cells and synthetic polymers are daunting but surmountable
Is Space Finite? Conventional wisdom says the universe is infinite. But it could be finite, merely givingthe illusion of infinity. Upcoming measurements may finally answer this ancient question.
Alan Turing's Forgotten Ideas in Computer Science Well known for the machine, test and thesis that bear his name, the British genius also anticipated neural-network computers and "hypercomputation"
A New Eye Opens on the Cosmos On the highest mountain in the pacific basin, a 10-year odyssey will culminate in the capture of first light for a telescope that may surpass space-based observatories
The Revival of Colored Cotton A new arrival on the Western fashion market, naturally pigmented cotton originally flourished some 5,000 years ago. Its revival today draws on stocks first developed and cultivated by Indians in South and Central America.
The Amateur Scientist Detecting "Hot" Clouds
Mathematical Recreations Tangling with Topology
Mar 1999
Global Climate Change on Venus Venus's climate, like Earth's, has varied over time - the result of newly appreciated connections between geologic activity and atmospheric change
A Little Big Bang A new collider will soon create matter as dense and hot as in the early universe
The Timing of Birth A hormone unexpectedly found in the human placenta turns out to influence the timing of delivery. This and related findings could yield much needed ways to prevent premature labor
Visualizing Human Embryos A technique called magnetic resonance microscopy is revealing the secrets of early human development
The Komodo Dragon On a few small islands in the Indonesian archipelago, the world's largest lizard reigns supreme
The Crash in the Machine Increasingly, automakers are relying on computer simulations of accidents to develop safer cars more quickly and efficiently
The Metamorphosis of Andrei Sakharov The inventor of the Soviet hydrogen bomb became an advocate of peace and human rights. What led him to his fateful decision?
The Amateur Scientist A Homemade High-Precision Thermometer
Mathematical Recreations The Synchronicity of Firefly Flashing
Feb 1999
Supersoft X-ray Stars and Supernovae Several years ago astronomers came across a new type of star that spews out unusually low energy x-rays. These so-called supersoft sources are now thought to be white dwarf stars that cannibalize their stellar companions and then, in many cases, explode
The Puzzle of Hypertension in African-Americans Genes are often invoked to account for why high blood pressure is so common among African-Americans. Yet the rates are low in Africans. This discrepancy demonstrates how genes and the environment interact
Cichlids of the Rift Lakes The extraordinary diversity of cichlid fishes challenges entrenched ideas of how quickly new species can arise
A Multifractal Walk down Wall Street The geometry that describes the shape of coastlines and the patterns of galaxies also elucidates how stock prices soar and plummet
How Limbs Develop A protein playfully named Sonic hedgehog is one of the long-sought factors that dictate the pattern of limb development
The Way to Go in Space To go farther into space, humans will first have to figure out how to get there cheaply and more efficiently. Ideas are not in short supply
Air-Breathing Engines For years, engineers have dreamed of building an aircraft that could reach hypersonic speeds, greater than Mach 5, or five times the speed of sound.
Space Tethers When humans begin to inhabit the moon and planets other than Earth, they may not use the modern technology of rockets.
Highways of Light Today's spacecraft carry their source of power.
Light Sails Science-fiction dreams of worlds beyond our own solar system have taken on a more realistic aspect since astronomers discovered that the universe contains planets in unexpectedly large numbers
Compact Nuclear Rockets Someday, in exploring the outer planets of our solar system, humankind will want to do more than send diminutive probes that merely fly rapidly by them.
Reaching for the Stars The notion of traveling to the stars is a concept compelling enough to recur in countless cultural artifacts, from Roman poetry to 20th-century popular music
The Amateur Scientist Tackling the Triple Point
Mathematical Recreations Origami Tessellations
Jan 1999
Surveying Space-time with Supernovae Exploding stars seen across immense distances show that the cosmic expansion may be accelerating - a sign that the universe may be driven apart by an exotic new form of energy
Cosmological Antigravity The long-derided cosmological constant-a contrivance of Albert Einstein's that represents a bizarre form of energy inherent in space itself-is one of two contenders for explaining changes in the expansion rate of the universe
Inflation in a Low-Density Universe Evidence has gradually accumulated that the universe has less matter, and therefore is expanding faster, than the theory of inflation traditionally predicts. But a more sophisticated version of the theory readily explains the observations
Child Care among the Insects Why do some insect parents risk their lives to care for their young?
Disarming Flu Viruses Coming soon: new medicines designed to treat the flu by halting viral replication in human tissues. The drugs may also serve as a novel kind of preventive
Y2K: So Many Bugs...So Little Time Fixing Y2K seems simple: change all two-digit years to four digits. But that tedious - and unexpectedly difficult - process takes more time than is left
DNA Microsatellites: Agents of Evolution? Repetitive DNA sequences play a surprising role in how bacteria - and perhaps higher organisms - adapt to their environments. On the downside, they have also been linked to human disease
Expeditions: To Save a Salmon On Vancouver Island, fisheries scientists are trying to find out whether commercial fishing and cohos can coexist
The Amateur Scientist Taking the Earth's Magnetic Pulse
Mathematical Recreations Division without Envy
Dec 1998
The Evolution of Galaxy Clusters The most massive objects in the universe are huge clusters of galaxies and gas that have slowly congregated over billions of years. The process of agglomeration may now be ending
Cloning for Medicine Now that genetically modified and copied mammals are a reality, biomedical researchers are starting to develop imaginative ways to use this technology
Making Ultrabright X-rays Radiation a billion times brighter than the sun's is illuminating a host of scientific and technical phenomena
Combating Prostate Cancer Recent advances in diagnosis and treatment promise to extend survival time and improve the quality of life for many patients
Leafy Sea Dragons These masters of camouflage are fierce predators - and one of the few species in which males become pregnant
Building the Better Bug Inserting new genes into a few specific insect species could stop some infectious diseases, benefit agriculture and produce innovative materials
Physicists in Wartime Japan During the most trying years of Japan's history, two brilliant schools of theoretical physics flourished
Sizing Up Software Unlike oil, steel or paper, software is an intangible commodity. This elusive quality makes computer programs difficult to quantify
The Amateur Scientist Sorting Molecules With Electricity
Mathematical Recreations Your Half's Bigger Than My Half!
Nov 1998
Natural Oil Spills In the Gulf of Mexico, a region famous for its many oil and gas fields, most of the petroleum flowing into the ocean leaks naturally from fissures in the seabed
The Meteorite Hunter, Part I: The Day the Sands Caught Fire A desert impact site demonstrates the wrath of rocks from space
Meteorite Hunters Part II: The Search for Greenland's Mysterious Meteor Caught on camera, the fireball that streaked across Arctic skies last December appeared to move too fast for anything from this solar system. A monthlong expedition on this island of ice hunted for remains - and answers
Glueballs Gluons, which hold protons together, can also clump into globs of pure glue
Evolution and the Origins of Disease The principles of evolution by natural selection are finally beginning to inform medicine
Mating Strategies of Spiders Spiders have evolved intriguing behaviors to woo their occasionally cannibalistic mates
Simulating Water and the Molecules of Life Computer modeling reveals how water affects the structures and dynamics of biological molecules such as proteins, yielding clues to their functions
100 Years of Magnetic Memories Although the technology is ubiquitous today, magnetic recording had a sluggish start. The underlying science was something of a mystery, applications were slow to emerge, and business and politics stifled development.
The Amateur Scientist Floating A Challenge
Mathematical Recreations Resurrection Shuffle
Oct 1998
Galaxies behind the Milky Way Over a fifth of the universe is hidden from view, blocked by dust and stars in the disk of our galaxy. But over the past few years, astronomers have found ways to peek through the murk
Designer Estrogens These compounds - also called SERMs - have evolved from mere laboratory curiosities into drugs that hold promise for preventing several major disorders in women
Secrets of the Slime Hag Loathsome though they may seem, hagfishes may also resemble the earliest animals to have a braincase - making them even older than the first animals to develop a backbone
The Asymmetry between Matter and Antimatter In 1999 new accelerators will start searching for violations in a fundamental symmetry of nature, throwing open a window to physics beyond the known
The Artistry of Microorganisms Colonies of bacteria or amoebas form complex patterns that blur the boundary between life and nonlife
Simon Newcomb: Astronomer with an Attitude The most celebrated American astronomer of the late 19th century advocated broad social and cultural reforms based on the use of scientific method
Computer Security and the Internet This past February hackers reached through the Internet to break into the computer networks at various U.S. Air Force and Navy sites.
How Hackers Break In... and How They Are Caught Port scanners, core dumps and buffer overflows are but a few of the many weapons in every sophisticated hacker's arsenal. Still, no hacker is invincible
How Computer Security Works Three types of safeguards offer a formidable defense against Internet intruders
Cryptography for the Internet E-mail and other information sent electronically are like digital postcards - they afford little privacy. Well-designed cryptography systems can ensure the secrecy of such transmissions.
The Case against Regulating Encryption Technology One of the pioneers of computer security says the U.S. government should keep its hands off cryptography
The Amateur Scientist Home Movies of an Invisible World
Mathematical Recreations Playing with Chocolate
Sep 1998
Preserving the Laetoli Footprints (Part 1) The discovery of hominid footprints in East Africa reshaped the study of human origins. Now conservators have protected the fragile tracks from destruction
Preserving the Laetoli Footprints (Part 2) The discovery of hominid footprints in East Africa reshaped the study of human origins. Now conservators have protected the fragile tracks from destruction
The Footprint Makers: An Early View I worked on my painting of the Laetoli footprint makers during the early fall of 1978, shortly after the discovery of the hominid trackway.
The Laetoli Diorama Only very rarely does the fossil record provide evidence of an actual event in human prehistory.
Weightlessness and the Human Body The effects of space travel on the body resemble some of the conditions of aging. Studying astronauts' health may improve medical care both in orbit and on the ground
Attention-Deficit Hyperactivity Disorder A new theory suggests the disorder results from a failure in self-control. ADHD may arise when key brain circuits do not develop properly, perhaps because of an altered gene or genes
Making New Elements Three new elements-110, 111 and 112-have been produced over the past several years. Scientists are now struggling to create 113 and 114. How many elements can they add to the periodic table?
The Evolution of the Periodic System From its origins some 200 years ago, the periodic table has become a vital tool for modern chemists
The Oort Cloud On the outskirts of the solar system swarms a vast cloud of comets, influenced almost as much by other stars as by our sun. The dynamics of this cloud may help explain such matters as mass extinctions on Earth
Thermophotovoltaics Semiconductors that convert radiant heat to electricity may prove suitable for lighting remote villages or powering automobiles
The Amateur Scientist Spooling the Stuff of Life
Mathematical Recreations Counting the Pyramid Builders
Aug 1998
Fusion and the Z Pinch A device called the Z machine has led to a new way of triggering controlled fusion with intense nanosecond bursts of x-rays
Low-Back Pain Low-back pain is at epidemic levels. Although its causes are still poorly understood, treatment choices have improved, with the body's own healing power often the most reliable remedy
Computing with DNA The manipulation of DNA to solve mathematical problems is redefining what is meant by "computation"
Monitoring and Controlling Debris in Space The path from Sputnik to the International Space Station has been littered with high-tech refuse, creating an environmental problem in outer space
A Quarter-Century of Recreational Mathematics The author of "Scientific American"'s column "Mathematical Games" from 1956 to 1981 recounts 25 years of amusing puzzles and serious discoveries
Irrigating Crops with Seawater As the world's population grows and freshwater stores become more precious, researchers are looking to the sea for the water to irrigate selected crops
Microdiamonds These tiny, enigmatic crystals hold promise both for industry and for the study of how diamond grows
The Philadelphia Yellow Fever Epidemic of 1793 One of the first major epidemics of the disease in the U.S., it devastated America's early capital. It also had lasting repercussions for the city and country
The Amateur Scientist Building a Consciousness of Streams
Mathematical Recreations Monks, Blobs and Common Knowledge
Jul 1998
The Mars Pathfinder Mission Last summer the first ever Mars rover found in situ evidence that the Red Planet may once have been hospitable to life
The Split Brain Revisited Groundbreaking work that began more than a quarter of a century ago has led to ongoing insights about brain organization and consciousness
The Single-Atom Laser A new type of laser that harnesses the energy of individual atoms reveals how light interacts with matter
Mating Strategies in Butterflies Butterflies meet, woo and win their mates using seductive signals and clever strategies honed by evolution
Léon Foucault Celebrated for his pendulum experiment in 1851, Foucault also produced decisive evidence against the particle theory of light, invented the gyroscope, perfected the reflecting telescope and measured the sun's distance
Defeating AIDS: What Will It Take? Ten years ago, when "Scientific American" published an issue devoted to AIDS (the acquired immunodeficiency syndrome), scientists knew that the disease, first identified in 1981, was caused by HIV (the human immunodeficiency virus).
HIV 1998: The Global Picture Worldwide, the populations most affected by the AIDS virus are often the least empowered to confront it effectively
Improving HIV Therapy Today's optimal treatments can work magic, but they are costly and onerous and do not work for everyone. What might the future bring?
How Drug Resistance Arises When anti-HIV therapy fails to keep HIV levels suppressed, the cause is often viral resistance to at least one of the drugs being administered.
Viral-Load Tests Provide Valuable Answers In the early 1990s tests that could accurately detect the amount of HIV in a patient's blood finally became available.
When Children Harbor HIV HIV infection is particularly difficult to combat in the young
Preventing HIV Infection Altering behavior is still the primary way to control the epidemic
HIV Vaccines: Prospects and Challenges Unlike vaccines for many viruses, those for HIV may have to go beyond generating antibodies. Devising approaches that will fully activate the immune system is far from simple
Avoiding Infection After HIV Exposure Treatment may reduce the chance of contracting HIV infection after a risky encounter
Coping With HIV's Ethical Dilemmas The issues are many and thorny
The Amateur Scientist A Year for the Oceans
Mathematical Recreations The Bellows Conjecture
Jun 1998
The Neurobiology of Depression The search for biological underpinnings of depression is intensifying. Emerging findings promise to yield better therapies for a disorder that too often proves fatal
A New Look at Quasars Recent observations from the Hubble Space Telescope may reveal the nature and origin of quasars, the mysterious powerhouses of the cosmos
Shrimp Aquaculture and the Environment An adviser to shrimp producers and an environmentalist present a prescription for raising shrimp responsibly
Quantum Computing with Molecules By taking advantage of nuclear magnetic resonance, scientists can coax the molecules in some ordinary liquids to serve as an extraordinary type of computer
Gravity Gradiometry A formerly classified technique used to navigate ballistic-missile submarines now helps geologists search for resources hidden underground
Alcohol in the Western World The role of alcohol in Western civilization has changed dramatically during this millennium. Our current medical interpretation of alcohol as primarily an agent of disease comes after a more complex historical relationship
Defibrillation: The Spark of Life In the 50 years since doctors first used electricity to restart the human heart, we have learned much about defibrillators and little about fibrillation
The Amateur Scientist Waiter, There's a Hair in My Hygrometer
Mathematical Recreations What a Coincidence!
May 1998
Six Months on Mir As the Shuttle-Mir program draws to a close, a veteran NASA astronaut reflects on her mission on board the Russian spacecraft and the implications for the International Space Station
How Cicadas Make Their Noise The loudest known insects, male cicadas are designed for sound. Their internal instrument is surprisingly complex
The Genetics of Cognitive Abilities and Disabilities Investigations of specific cognitive skills can help clarify how genes shape the components of intellect
Television's Bright New Technology The plasma display panel is finally making good on a decades-old promise: a big, bright screen so thin it can be hung on a wall. But mainstream success requires that engineers find a way to get prices down from the current $11,000
Digital Television: Here at Last After a long and contentious process, a digital standard in the U.S. has finally emerged. It will soon replace today's antiquated television system
Japanese Temple Geometry During Japan's period of national seclusion (1639-1854), native mathematics thrived, as evidenced in "sangaku"-wooden tablets engraved with geometry problems hung under the roofs of shrines and temples
A Calculus of Risk Financial engineering can lessen exposure to the perils of running a multibillion-dollar business or a small household. But mathematical models used by this discipline may present a new set of hazards
The Amateur Scientist Sensing Subtle Tsunamis
Mathematical Recreations Cementing Relationships
Apr 1998
Cosmic Antimatter Antiparticles are rare and maddeningly elusive. But they may hold clues to some of the mysteries of astrophysics
Post-Polio Syndrome Decades after recovering much of their muscular strength, survivors of paralytic polio are reporting unexpected fatigue, pain and weakness. The cause appears to be degeneration of motor neurons
Science in Pictures: The Earliest Views Re-creating the experiments of pioneering microscopists reveals what they actually saw with their simple, single-lens instruments
How Females Choose Their Mates Females often prefer to mate with the most flamboyant males. Their choice may be based on a complex interaction between instinct and imitation
Laser Scissors and Tweezers Researchers are using lasers to grasp single cells and tinier components in vises of light while delicately altering the held structures. These lasers offer new ways to investigate and manipulate cells
Wireless Technologies Special Report
New Satellites for Personal Communications Fleets of satellites will soon make it possible to reach someone anywhere on the earth, using nothing more than a small handset
Telecommunications for the 21st Century Systems based on satellites and high-altitude platforms will merge with optical-fiber and terrestrial wireless networks to provide global, high data-rate, mobile communications
Terrestrial Wireless Networks Seamless switching between networks will draw users to wireless data services. A working model is now in operation
Moving beyond Wireless Voice Systems Cell phones are but one application of wireless communications. The technology also enables accurate position determination and the monitoring of remote sites
Spread-Spectrum Radio Dicing information into digital bundles and transmitting them at low power over different frequencies can enable millions of people to send and receive simultaneously
The Amateur Scientist Making Experiments out of Thin Air
Mathematical Recreations Repealing the Law of Averages
Mar 1998
The Bose-Einstein Condensate Three years ago in a Colorado laboratory, scientists realized a long-standing dream, bringing the quantum world closer to the one of everyday experience
The Challenge of Antibiotic Resistance Certain bacterial infections now defy all antibiotics. The resistance problem may be reversible, but only if society begins to consider how the drugs affect "good" bacteria as well as "bad"
Nanolasers Semiconductor lasers have shrunk to dimensions even smaller than the wavelength of the light they emit. In that realm, quantum behavior takes over, enabling more efficient and faster devices
Animating Human Motion Computer animation is becoming increasingly lifelike. Using simulation, a technique based on the laws of physics, researchers have created virtual humans who run, dive, bicycle and vault
The Caiman Trade The contraband trade in caiman skins shows how "sustainable utilization" of endangered species fails to sustain them
Preventing the Next Oil Crunch Enough oil remains in the earth to fill the reservoir behind Hoover Dam four times over-and that's just counting the fraction of buried crude that is relatively easy to recover and refine.
The End of Cheap Oil Global production of conventional oil will begin to decline sooner than most people think, probably within 10 years
Mining for Oil More oil is trapped in Canadian sands than Saudi Arabia holds in its reserves. The technology now exists to exploit this vast resource profitably
Oil Production in the 21st Century Recent innovations in underground imaging, steerable drilling and deepwater oil production could recover more of what lies below
Liquid Fuels from Natural Gas Natural gas is cleaner and more plentiful than oil. New ways to convert it to liquid form may soon make it just as cheap and convenient to use in vehicles
The Amateur Scientist The Pleasures of Pond Scum
Mathematical Recreations Glass Klein Bottles
Feb 1998
The Origin of Birds and Their Flight Anatomical and aerodynamic analyses of fossils and living birds show that birds evolved from small, predatory dinosaurs that lived on the ground
Scientists in Black In a unique collaboration, scientists and intelligence officials are working together to find out what the U.S. government's vast secret archives can reveal about the earth
The Viking Longship Long, narrow ships packed with warriors helped to make the Vikings the dominant power in Europe for three centuries, beginning in about A.D. 800
The Theory Formerly Known as Strings The Theory of Everything is emerging as one in which not only strings but also membranes and black holes play a role
The Search for Blood Substitutes The threat of global shortages of blood and fears about contamination have hastened attempts to find life-sustaining alternatives.
Greenland Ice Cores: Frozen in Time Ice, frozen in place for tens of thousands of years, provides scientists with clues to past-and future-climate
Everyday Exposure to Toxic Pollutants Environmental regulations have improved the quality of outdoor air. But problems that persist indoors have received too little attention
The Amateur Scientist Bird-Watching by the Numbers
Mathematical Recreations Tight Tins for Round Sardines
Jan 1998
The Architecture of Life A universal set of building rules seems to guide the design of organic structures-from simple carbon compounds to complex cells and tissues
Burial of Radioactive Waste under the Seabed Although the notion troubles some environmentalists, the disposing of nuclear refuse within oceanic sediments merits consideration
Bacterial Gene Swapping in Nature Genes travel between independent bacteria more often than once was assumed. Study of that process can help limit the risks of releasing genetically engineered microbes into the environment
The Ulysses Mission The first space probe to be sent on a "polar" trajectory has made some remarkable discoveries on its first orbit around the sun
Lise Meitner and the Discovery of Nuclear Fission One of the discoverers of fission in 1938, Meitner was at the time overlooked by the Nobel judges. Racial persecution, fear and opportunism combined to obscure her contributions
Picosecond Ultrasonics Brief pulses of high-frequency sound allow experimenters to probe connections inside a computer chip
The Placebo Effect Colds, asthma, high blood pressure and heart disease are among the many conditions that can respond to treatment with a placebo. Should doctors be prescribing sugar pills?
Leonardo and the Invention of the Wheellock Leonardo da Vinci's notebooks are full of inventions, from intricate gun parts to bicycles to automobiles. But were any of Leonardo's many creations actually made during his lifetime?
The Amateur Scientist A Kitchen Centrifuge
Mathematical Recreations Double Bubble, Toil and Trouble
Dec 1997
Metal Clusters and Magic Numbers Investigations of tiny lumps of metal can help bridge the gap in physicists' understanding of the differences between isolated atoms and bulk solids
The Case for Relic Life on Mars A meteorite found in Antarctica offers strong evidence that Mars has had - and may still have - microbial life
Williams Syndrome and the Brain To gain fresh insights into how the brain is organized, investigators are turning to a little known disorder
Tracking a Dinosaur Attack The efforts of a sculptor and a paleontologist reveal details of a 100-million-year-old skirmish
Exploiting Zero-Point Energy Energy fills empty space, but is there a lot to be tapped, as some propound? Probably not
Building the Biggest Our age worships small things: the microchip, recombinant genes, mechanical parts built at the molecular scale.
The Longest Suspension Bridge The Akashi Kaikyo Bridge has broken many records and weathered an earthquake--even while it is being completed
The World's Tallest Buildings Malaysia's Petronas Twin Towers serve as both a cultural and an economic symbol
Building a New Gateway to China The largest public-works upgrade on earth calls for, among other things, a new airport, two world-class bridges and two submerged crossings of Victoria Harbor
Do We Still Need Skyscrapers? The Industrial Revolution made skyscrapers possible. The Digital Revolution makes them (almost) obsolete
The Amateur Scientist Taking Back the Final Frontier
Mathematical Recreations Cat's Cradle Calculus Challenge
Nov 1997
Mercury: The Forgotten Planet Although one of Earth's nearest neighbors, this strange world remains, for the most part, unknown
Fermat's Last Stand His most notorious theorem baffled the greatest minds for more than three centuries. But after 10 years of work, one mathematician cracked it
Taking Nuclear Weapons off Hair-Trigger Alert It is time to end the practice of keeping nuclear missiles constantly ready to fire. This change would greatly reduce the possibility of a mistaken launch
The Parasitic Wasp's Secret Weapon Parasitic wasps must develop inside living caterpillars. They survive this hostile environment by smuggling in a virus that suppresses their host's immune system
Fighting Computer Viruses Biological metaphors offer insight into many aspects of computer viruses and can inspire defenses against them
Great Zimbabwe For centuries, this ancient Shona city stood at the hub of a vast trade network. The site has also been at the center of a bitter debate about African history and heritage
Making Rice Disease Resistant For the first time, scientists have used genetic engineering to protect this essential crop from disease
The Amateur Scientist Caught in a Wind Tunnel
Mathematical Recreations The Lore and Lure of Dice
Oct 1997
Transportation's Perennial Problems The congestion, accidents and pollution that plague modern travel are hardly new. History and recent research suggest they may remain intractable for generations to come
The Past and Future of Global Mobility With growing wealth, people everywhere travel farther and faster. That trend inevitably brings a shift in the dominant transportation technologies
13 Vehicles That Went Nowhere Perhaps "nowhere" is too harsh. But all these transportation concepts - however brilliant or eccentric - fell far short of their enthusiasts' great hopes.
Hybrid Electric Vehicles They will reduce pollution and conserve petroleum. But will people buy them, even if the vehicles have astounding fuel efficiency?
Flywheels in Hybrid Vehicles A rapidly spinning flywheel combines with a gas-turbine engine to power a novel hybrid electric vehicle
Automated Highways Cars that drive themselves in tight formation might alleviate the congestion now plaguing urban freeways
Unjamming Traffic with Computers Insights gleaned from realistic simulations are already moving from computer screens to asphalt
Now That Travel Can Be Virtual, Will Congestion Virtually Disappear? The idea that telecommunications technology could substitute for travel dawned on people soon after the invention of the telephone.
Driving to Mach 1 "Jetmobiles" try to go supersonic
Speed versus Need Rugged mountain climbers, bamboo rigs built for two, three-speeds with banana seats-bicycles, in their many forms, exist the world over.
How High-Speed Trains Make Tracks In Europe and Japan, train manufacturers are gearing up to achieve ultrafast speeds routinely, without relying on levitation
Fast Trains: Why the U.S. Lags The reasons are more political than technological
Maglev: Racing to Oblivion? Two years ago the world's only magnetically levitated train in commercial service shut down.
Straight Up into the Blue Tiltrotors, which take off like a helicopter but fly like an airplane, will soon make their military debut. Can civilian applications be far behind?
The Lure of Icarus With new designs and materials, human-powered fliers challenge the distance record
A Simpler Ride into Space Technological advances may allow rockets of the next century to operate much as aircraft do today. That change might cut the cost of reaching orbit by 10-fold
Faster Ships for the Future New designs for oceangoing freighters may soon double their speeds
Microsubs Go to Sea Small, maneuverable, self-contained - these tiny submersibles may someday take a human to the bottom of the sea
Elevators on the Move Elevator technology is taking off in new directions, including sideways
The Amateur Scientist Recording the Sounds of Life
Mathematical Recreations Two-Way Jigsaw Puzzles
Sep 1997
In Search of AIDS-Resistance Genes A genetic trait that protects against AIDS has now been uncovered, and others are emerging. The findings open entirely new avenues for developing preventives and therapies
The Discovery of the Top Quark Finding the sixth quark involved the world's most energetic collisions and a cast of thousands
Building Doors into Cells With the help of recombinant DNA technology, researchers have learned how to create artificial pores that might be used to deliver drugs or act as biosensors to detect toxic chemicals.
Running on Water The secret of the basilisk lizard's strategy lies in its stroke
Creating False Memories Researchers are showing how suggestion and imagination can create "memories" of events that did not actually occur
Life in the Provinces of the Aztec Empire The lives of the Aztec common people were far richer and more complex than the official histories would have us believe.
Booming Sand Though known for centuries, sound-producing sand remains one of nature's more puzzling phenomena
The Amateur Scientist Unraveling the Secrets of Monarchs
Mathematical Recreations Empires and Electronics
Aug 1997
Mitochondrial DNA in Aging and Disease Defects in DNA outside the chromosomes - in cell structures called mitochondria - can cause an array of disorders, perhaps including many that debilitate the elderly
Lightning Control with Lasers Scientists seek to deflect damaging lightning strikes using specially engineered lasers
Lightning between Earth and Space Scientists discover a curious variety of electrical activity going on above thunderstorms
Space Age Archaeology Remote-sensing techniques are transforming archaeology. Excavations may become less essential as researchers explore hidden sites and examine buried artifacts without unearthing them
Glandular Gifts The way to a katydid's heart is through her stomach
The Top-Secret Life of Lev Landau KGB archives reveal that the Soviet genius co-authored an anti-Stalin manifesto
The Machinery of Thought Studies of the brains of monkeys and, more recently, of humans are revealing the neural underpinnings of working memory, one of the mind's most crucial functions
The Amateur Scientist Getting a Charge out of Rain
Mathematical Recreations Empires on the Moon
Jul 1997
China's Buddhist Treasures at Dunhuang Cave temples along the ancient Silk Road document the cultural and religious transformations of a millennium. Researchers are striving to preserve these endangered statues and paintings
Gamma-Ray Bursts New observations illuminate the most powerful explosions in the universe
Xenotransplantation After struggling for decades with a shortage of donated organs from cadavers, transplant surgeons may soon have another source to tap
Strong Fabrics for Fast Sails Composite fabrics first developed for the sails of racing yachts may soon find use in parachutes and research balloons
Asbestos Revisited Once considered safe enough to use in toothpaste, this unique substance has intrigued people for more than 2,000 years
Global Population and the Nitrogen Cycle Feeding humankind now demands so much nitrogen-based fertilizer that the distribution of nitrogen on the earth has been changed in dramatic, and sometimes dangerous, ways
Taking Computers to Task Coming generations of computers will be more fun and engaging to use. But will they earn their keep in the workplace?
The Amateur Scientist How-To's of Butterfly Rookeries
Mathematical Recreations Squaring the Square
Jun 1997
Iran's Nuclear Puzzle Rich in fossil-fuel resources, Iran is pursuing a nuclear power program difficult to understand in the absence of military motives
Configurable Computing Computers that modify their hardware circuits as they operate are opening a new era in computer design. Because they can filter data rapidly, they excel at pattern recognition, image processing and encryption
Early Hominid Fossils from Africa A new species of "Australopithecus", the ancestor of "Homo", pushes back the origins of bipedalism to some four million years ago
Panoramas of the Seafloor Modern sonar techniques map the continental margins of the U.S. and reveal the richly varied scenery usually hidden underwater
Searching for Digital Pictures Computers that can reason about images may be able to pick out distinct features of a person, place or object from photograph archives
Making Gene Therapy Work: Table of Contents Special Report
Overcoming the Obstacles to Gene Therapy Treating disease by providing needed genes remains a compelling idea, but clinical and basic researchers still have much to do before gene therapy can live up to its promise
Nonviral Strategies for Gene Therapy Many drawbacks of viral gene delivery agents might be overcome by nonviral systems. Studies in patients suggest these systems have potential as therapies and as vaccines
Gene Therapy for Cancer Inserted genes could in theory arrest tumor growth or even AIDS
Gene Therapy for the Nervous System Inserting genes into brain cells may one day offer doctors a way to slow, or even reverse, the damage from degenerative neurological disease
What Cloning Means for Gene Therapy The recently debuted technology for cloning is usually discussed as a means of creating genetic copies of whole adult individuals.
Bringing Schrödinger's Cat to Life Recent experiments have begun to demonstrate how the weird world of quantum mechanics gives way to the familiarity of everyday experience
The Amateur Scientist Getting Inside an Ant's Head
Mathematical Recreations The Sifting Sands of Factorland
May 1997
Divided We Fall: Cooperation among Lions Although they are the most social of all cats, lions cooperate only when it is in their own best interest
Managing Human Error in Aviation Mistakes by flight crews contribute to more than two thirds of aviation accidents. Training to enhance team performance may reduce potentially fatal errors
Integrins and Health Discovered only recently, these adhesive cell-surface molecules have quickly revealed themselves to be critical to proper functioning of the body and to life itself
The Coming Climate Meteorological records and computer models permit insights into some of the broad weather patterns of a warmer world
New Chemical Tools to Create Plastics Small molecular machines called metallocene catalysts have revolutionized the industrial synthesis of valuable plastics
Galaxies in the Young Universe By comparing distant primeval galaxies with older ones nearby, astronomers hope to determine how galaxies form and evolve
Seeking a Better Way to Die As the U.S. Supreme Court ponders physician-assisted suicide, health care providers strive to improve care of the dying
The Amateur Scientist When Hazy Skies Are Rising
Mathematical Recreations Big Game Hunting in Primeland
Apr 1997
Can Sustainable Management Save Tropical Forests? Sustainability proves surprisingly problematic in the quest to reconcile conservation with the production of tropical timber
Black Holes and the Information Paradox What happens to the information in matter destroyed by a black hole? Searching for that answer, physicists are groping toward a quantum theory of gravity
Out of Africa Again... and Again? Africa is the birthplace of humanity. But how many human species evolved there? And when did they emigrate?
Combinatorial Chemistry and New Drugs An innovative technique that quickly produces large numbers of structurally related compounds is changing the way drugs are discovered
How Erosion Builds Mountains An understanding of how tectonic, erosional and climatic forces interact to shape mountains permits clearer insights into the earth's history
Extremophiles These microbes thrive under conditions that would kill other creatures. The molecules that enable extremophiles to prosper are becoming useful to industry
The Science of Murphy's Law Life's little annoyances are not as random as they seem: the awful truth is that the universe is against you
Jules Verne, Misunderstood Visionary Discovery of a long-lost novel reveals that, from the start, the father of science fiction was gravely concerned with the dangers of technology
The Amateur Scientist The Joys of Armchair Ornithology
Mathematical Recreations Knight's Tours
Mar 1997
SOHO Reveals the Secrets of the Sun A powerful new spacecraft, the Solar and Heliospheric Observatory, or SOHO, is now monitoring the sun around the clock, providing new clues about our nearest star
The Internet Fulfilling the Promise
The Internet: Bringing Order From Chaos The Internet, as everybody with a modem now knows, has fallen victim to its own success.
Searching the Internet Combining the skills of the librarian and the computer scientist may help organize the anarchy of the Internet
Going Digital Electronic libraries will make today's Internet pale by comparison. But building them will not be easy
Filtering Information On The Internet Look for the labels to decide if unknown software and World Wide Web sites are safe and interesting
Interfaces For Searching the Web The rapid growth of the World Wide Web is outpacing current attempts to search and organize it. New user interfaces may offer a better approach
Websurfing Without a Monitor When I hook up to the Internet to check out the news on CNN, to peruse a colleague's latest paper or to see how Adobe's stock price is doing, I leave the display of my laptop turned off.
Multilingualism on the Internet In recent years, American culture has increased its worldwide influence through international trade and Hollywood productions.
Trusted Systems Devices that enforce machine-readable rights to use the work of a musician or author may create secure ways to publish over the Internet.
Preserving the Internet An archive of the Internet may prove to be a vital record for historians, businesses and governments
Psychiatry's Global Challenge An evolving crisis in the developing world signals the need for a better understanding of the links between culture and mental disorders
Discovering Genes for New Medicines By identifying human genes involved in disease, researchers can create potentially therapeutic proteins and speed the development of powerful drugs
Heike Kamerlingh Onne's Discovery of Superconductivity The turn-of-the-century race to reach temperatures approaching absolute zero led to the unexpected discovery of electric currents that flowed with no resistance
Plants That Warm Themselves Some plants produce extraordinary heat when they bloom. A few even regulate their temperature within narrow limits, much as if they were warm-blooded animals
The Rising Seas Although some voice concern that global warming will lead to a meltdown of polar ice, flooding coastlines everywhere, the true threat remais difficult to gauge
Mathematical Recreations Juniper Green
The Amateur Scientist Algorithm of the Gods
Feb 1997
Immunotherapy for Cocaine Addiction Newly developed compounds derived from the immune system may help combat cocaine abuse by destroying the drug soon after it enters the bloodstream
Satellite Radar Interferometry From hundreds of kilometers away in space, orbiting instruments can detect subtle buckling of the earth's crust
The Ghostliest Galaxies Astronomers have found more than 1,000 "low-surface-brightness" galaxies over the past decade, significantly altering our views of how galaxies evolve and how mass is distributed in the universe
The Lesser Known Edison In addition to his famous inventions, Thomas Edison's fertile imagination gave the world a host of little known technologies, from talking dolls to poured-concrete houses
Why and How Bacteria Communicate Bacteria converse with one another and with plants and animals by emitting and reacting to chemical signals. The need to "talk" may help explain why the microbes synthesize a vast array of compounds
The Challenge of Large Numbers As computer capabilities increase, mathematicians can better characterize and manipulate gargantuan figures. Even so, some numbers can only be imagined
The Benefits and Ethics of Animal Research Experiments on animals are a mainstay of modern medical and scientific research. But what are the costs and what are the returns?
Animal Research Is Wasteful and Misleading The use of animals for research and testing is only one of many investigative techniques available.
Animal Research Is Vital to Medicine Experiments using animals have played a crucial role in the development of modern medical treatments, and they will continue to be necessary as researchers seek to alleviate existing ailments and respond to the emergence of new disease.
Trends in Animal Research Increased concern for animals, among scientists as well as the public, is changing the ways in which animals are used for research and safety testing
The Amateur Scientist A Picture-Perfect Comet
Mathematical Recreations Crystallography of a Golf Ball
Jan 1997
Cosmic Rays at the Energy Frontier These particles carry more energy than any others in the universe. Their origin is unknown but may be relatively nearby
Understanding Parkinson's Disease The smoking gun is still missing, but growing evidence suggests highly reactive substances called free radicals are central players in this common neurological disorder
Tackling Turbulence with Supercomputers Computers only recently became powerful enough to illuminate simple examples of this great classical problem. In some cases, they will let engineers control it
Transgenic Livestock as Drug Factories By introducing key human genes into mammals, biologists can induce dairy animals to produce therapeutic proteins in their milk
How the Blind Draw Blind and sighted people use many of the same devices in sketching their surroundings, suggesting that vision and touch are closely linked
Experimental Flooding in Grand Canyon Scientists monitor a controlled deluge that was staged in the early spring of 1996 solely for the benefit of the environment in and around the Colorado River
The Einstein-Sziland Refrigerator Two visionary theoretical physicists joined forces in the 1920s to reinvent the household refrigerator
Science versus Antiscience? Movements lumped under the term "antiscience" have disparate causes, and not all pose as much of a threat as has been claimed
The Amateur Scientist Catch a Comet by Its Tail
Mathematical Recreations Alphamagic Squares
Dec 1996
The Specter of Biological Weapons States and terrorists alike have shown a growing interest in germ warfare. More stringent arms-control efforts are needed to discourage attacks
Primordial Deuterium and the Big Bang Nuclei of this hydrogen isotope formed in the first moments of the big bang. Their abundance offers clues to the early evolution of the universe and the nature of cosmic dark matter
Creating Nanophase Materials The properties of these ultrafine-grained substances, now found in a range of commercial products, can be custom-engineered
Cell Suicide in Health and Disease Cells can - and often do - kill themselves, in a process known as apoptosis. This capacity is essential to the proper functioning of the body; flawed regulation may lie behind many diseases
Atmospheric Dust and Acid Rain Emissions of acidic air pollutants have fallen dramatically. Why is acid rain still a problem? Atmospheric dust may be part of the answer.
A Cricket Robot Can a simple electromechanical system perform a complex behavior of a living creature? There was one sure way to find out
Daily Life in Ancient Egypt Workmen and their families lived some 3,000 years ago in the village now known as Deir el-Medina. Written records from the unusually well educated community offer fascinating descriptions of everyday activities
Why Freud Isn't Dead Skeptics continue to challenge Sigmund Freud's ideas about the mind. Yet no unquestionably superior theory or therapy has rendered psychoanalysis completely obsolete
The Amateur Scientist Dissecting the Brain with Sound
Mathematical Recreations Cows in the Maze
Nov 1996
The Case for Electric Vehicles New technological developments have put practical electric cars within reach, but politics may slow the shift away from internal-combustion engines
Immunity and the Invertebrates The fabulously complex immune systems of humans and other mammals evolved over hundreds of millions of years - in sometimes surprising ways
Sharks and the Origins of Vertebrate Immunity Sharks, which have existed for as many as 450 million years, offer glimpses of a distant period in the evolution of the immune system.
Quantum Seeing in the Dark Quantum optics demonstrates the existence of interaction-free measurements: the detection of objects without light - or anything else - ever hitting them
Global Climatic Change on Mars Today a frozen world, Mars at one time may have had more temperate conditions, with flowing rivers, thawing seas, melting glaciers and, perhaps, abundant life
Can China Feed Itself? Some surprisingly reasonable policy changes would enable the world's largest nation to produce more food for its 1.2 billion citizens
Dyslexia A new model of this reading disorder emphasizes defects in the language-processing rather than the visual system. It explains why some very smart people have trouble learning to read
Rock Art in Southern Africa Paintings and engravings made by ancestors of the San peoples encode the history and culture of a society thousands of years old
The Amateur Scientist Much Ado about Nothing
Mathematical Recreations A Guide to Computer Dating
Oct 1996
Single Mothers and Welfare For the first time since the Great Depression, large numbers of families are homeless. Recent welfare revisions will put even more women and children on the stress.
Microbes Deep inside the Earth Recently discovered microorganisms that dwell within the earth's crust could reveal clues to the origin of life
Friction at the Atomic Scale Long neglected by physicists, the study of friction's atomic-level origins, or nanotribology, indicates that the force stems from various unexpected sources, including sound energy
Controlling Computers with Neural Signals Electrical impulses from nerves and muscles can command computers directly, a method that aids people with physical disabilities
Ten Days under the Sea Living underwater in the world's only habitat devoted to science, six aquanauts studied juvenile corals and fought off "the funk"
How an Underwater Habitat Benefits Marine Science Scuba divers joke that there are two ways to avoid decompression sickness, the rare but dreaded "bends": don't go down, or don't come up.
Charles Darwin and Associates, Ghostbusters When the scientific establishment put a spiritualist on trial, the co-discoverers of natural selection took opposing sides
Confronting Science's Logical Limits The mathematical models now used in many scientific fields may be fundamentally unable to answer certain questions about the real world. Yet there may be ways around these problems
Sounding Out Science Prince William Sound is recovering, seven years after the "Exxon Valdez" disaster. But the spill's scientific legacy remains a mess
The Amateur Scientist Working in a Vacuum
Mathematical Recreations Monopoly Revisited
Sep 1996
How Cancer Arises An explosion of research is uncovering the long-hidden molecular underpinnings of cancer - and suggesting new therapies
How Cancer Spreads Tumor cells roam the body by evading the controls that keep normal cells in place. That fact offers clues to fighting cancer
Causes and Prevention Many of the culprits most publicized as causes of cancer actually account for a relatively small fraction of deaths. The good news: we can do more to protect ourselves. And a growing area of study - chemoprevention - is attempting to make the task easier.
What Causes Cancer? The top two causes - tobacco and diet - account for almost two thirds of all cancer deaths and are among the most correctable
Strategies For Minimizing Cancer Risk Simple, realistic preventive measures could save hundreds of thousands of lives every year in developed countries alone
Chemoprevention of Cancer Someday people should be able to avoid cancer or delay its onset by taking specially formulated pills or foods
Is Hormone Replacement Therapy a Risk? Thanks to advances in public health and medicine, the average American woman will be postmenopausal for about one third of her life.
Toward Earlier Detection New technology promises not only to detect cancers earlier and more accurately but also to catch tumors in their precancerous state, when the disease still might be prevented outright. The same basic instruments should help physicians to distinguish patients who need minimal treatment from those who need the most aggressive interventions.
Advances in Cancer Detection Tests to look for the presence of a tumor before any symptoms appear may save more lives than new drug therapies do
Advances in Tumor Imaging New tools yield a three-dimensional view inside the body and automated advice on interpreting the anatomical landscape
Should Women in Their 40s Have Mammograms? For at least four years now, breast cancer specialists have been heatedly arguing among themselves about whether women in their forties benefit from having routine mammograms.
Does Screening for Prostate Cancer Make Sense? Since 1990 the reported number of new cases of prostate cancer has tripled, from fewer than 100,000 annually to an estimated 317,000 this year.
Improving Conventional Therapy The mainstays of cancer treatment - surgery, radiation and chemotherapy - are being refined and combined in ways that can help patients enjoy longer, more fulfilling lives.
Advancing Current Treatments for Cancer Surgery, radiation and chemotherapy can now cure many cases of cancer. Future methods will be even more effective
When are Bone Marrow Transplants Considered? Bone marrow transplants can help to compensate for the damaging effects of intense chemotherapy.
Twelve Major Cancers The pages that follow provide facts and figures about the 12 cancers that affect the most Americans (excluding basal cell and squamous cell skin cancers, which are very common but rarely fatal).
Therapies of the Future Fascinating new approaches to treatment would combat cancers without the devastating side effects of many current therapies. Some capitalize on insights into how the immune system might be enlisted to destroy malignancies. Others are based on detailed knowledge of how tumors grow and spread.
Immunotherapy for Cancer As knowledge about the immune system grows, scientists are devising ways, using the body's own defenses, to attack cancer
New Molecular Targets for Cancer Therapy Investigators are exploiting the characteristic molecular abnormalities of cancers in new approaches to treatment
Fighting Cancer by Attacking Its Blood Supply By interfering with the expanding network of blood vessels in tumors, researchers hope to cut off the underlying support system
Living with Cancer (Introduction) There are ways to cope successfully with the physical, psychological and practical challenges of the disease. Resources are available to patients who know where to look. Even pain can usually be controlled - if caregivers award the problem the attention it deserves.
Cancer's Psychological Challenges Cancer patients today have many options for easing distress. These interventions may not prolong life, but they can improve its quality
Alternative Cancer Treatments Miraculous cures are a myth, but some regimens may well improve the quality of life for patients
Controlling the Pain of Cancer Despite enormous advances in treating pain, many cancer patients still suffer needlessly. Some simple practices can make a difference
What Are Obstacles to Ideal Care? Many patients do not know that being in a clinical trial is an option.
Finding More Information Fortunately, access to incisive knowledge about cancer and its treatment is easier to obtain than ever before.
The Amateur Scientist The Pleasures of Exploring Ponds
Mathematical Recreations The Interrogator's Fallacy
Aug 1996
Smart Cards As potential applications grow, computers in the wallet are making unobtrusive inroads
The Stellar Dynamo Sunspot cycles - on other stars - are helping astronomers study the sun's variations and the ways they might affect the earth
Gradients that Organize Embryo Development A few crucial molecular signals give rise to chemical gradients that organize the developing embryo
Sands of the World One of the most common elements on the earth's surface, sand is also one of the most various
Probing High-Temperature Superconductivity Recent experiments exploiting subtle quantum effects yield important clues about why some ceramics conduct electricity without resistance
The Mystery of Lambic Beer An ancient brewing technique produces a beverage so complex that it is still yielding its secrets to organic chemists
Ring Bubbles of Dolphins A number of bottlenose dolphins in Hawaii can create shimmering, stable rings and helices of air as part of play
Gaining on Fat As a costly epidemic of obesity spreads through the industrial world, scientists are uncovering the biological roots of this complex disease. The work offers tantalizing hope of new ways to treat, and prevent, the health risks of excess weight
The Amateur Scientist Detecting Micron-Size Movements
Mathematical Recreations Shedding a Little Darkness
Jul 1996
Next-Generation Compact Discs A novel agreement among competing electronics companies has delivered an innovative plan for compatible "DVD" products - the first are due out this fall
Blue-Laser CD Technology Coaxing semiconductor crystals into lasing blue light is no easy task, but the rewards - among them, greater storage space on optical disks - are well worth the wait
Sunlight and Skin Cancer Although most skin cancers appear in older people, the damage often begins decades earlier, when the sun's rays mutate a key gene in a single cell
The Nature of Space and Time Two relativists present their distinctive views on the universe, its evolution and the impact of quantum theory
The Hidden World of Surgery In his finely resolved images of surgery, a photographer sees clues to who and what we are
The Mother of Mass Extinctions Disaster struck 250 million years ago, when the worst decimation in the earth's history occurred. Called the end-Permian mass extinction, it marks a fundamental change in the development of life
Who Owns Digital Works? Computer networks challenge copyright law, but some proposed cures may be as bad as the disease
Exoskeletal Sensors for Walking To move their limbs, cockroaches, crabs and spiders rely on organs in their exoskeletons that act as strain gauges. Their method of locomotion could facilitate the design of multilegged robots
The Amateur Scientist Covert Observations of Nesting Sparrows
Mathematical Recreations Arithmetic and Old Lace
Jun 1996
Semiconductor Subsidies Did the U.S. government spend more than $700 million to achieve a goal that might have been attained for much less?
Training the Olympic Athlete Sports science and technology are today providing elite competitors with the tiny margins needed to win in world-class competition
Science in the Sky The International Space Station will be the most expensive object ever built. Although many scientists oppose the grandiose scheme, its political momentum now appears unstoppable
Can Nuclear Waste Be Stored Safely at Yucca Mountain? Studies of the mountain's history and geology can contribute useful insights but not unequivocal conclusions
The Reluctant Father of Black Holes Albert Einstein's equations of gravity are the foundation of the modern view of black holes; ironically, he used the equations in trying to prove these objects cannot exist
The Art of Charles R. Knight Long before the film "Jurassic Park", Knight's illustrations brought dinosaurs to life in the public's mind.
Taxoids: New Weapons against Cancer The chemists who developed the cancer-fighting agent taxol are creating a family of similar compounds that may one day help combat the disease.
The Amateur Scientist Homemade Microgram Electrobalances
Mathematical Recreations Tales of a Neglected Number
May 1996
The Horror of Land Mines Land mines kill or maim more than 15,000 people each year. Most victims are innocent civilians. Many are children. Still, mines are planted by the thousands every day
The Kuiper Belt Rather than ending abruptly at the orbit of Pluto, the outer solar system contains an extended belt of small bodies
Uncovering New Clues to Cancer Risk A growing discipline called molecular epidemiology is attempting to find early biological signposts for heightened risk of cancer. The research should enhance prevention of the disease
Software for Reliable Networks Techniques that enable distributed computing systems to reorganize themselves can restore operation when one part crashes
The Pursuit of Happiness New research uncovers some anti-intuitive insights into how many people are happy - and why
The Beluga Whales of the St. Lawrence River Although they are protected by law from hunters, these whales must struggle to survive the threat of industrial pollution
The Lost Technology of Ancient Greek Rowing The navies of classical Greece took advantage of the sliding stroke, a technique that 19th-century competitive rowers later reinvented
Hanford's Nuclear Wasteland The U.S. is spending billions to clean up its nuclear weapons complexes. At one of the most contaminated sites, no one knows how much the project will cost, how long it will take or how much good it will do
The Amateur Scientist Detecting Natural Electromagnetic Waves
Mathematical Recreations The Sculptures of Alan St. George
Apr 1996
Ten Years of the Chornobyl Era The environmental and health effects of nuclear power's greatest calamity will last for generations
The Birth of Complex Cells Humans, together with all other animals, plants and fungi, owe their existence to the momentous transformation of tiny, primitive bacteria into large, intricately organized cells
Searching for Life on Other Planets Life remains a phenomenon we know only on Earth. But an innovative telescope in space could change that by detecting signs of life on distant planets
Smart Rooms In creating computer systems that can identify people and interpret their actions, researchers have come one step closer to building helpful home and work environments
Alcohol in American History National binges have alternated with enforced abstinence for 200 years, but there may be hope for moderation
Captured in Amber The exquisitely preserved tissues of insects in amber reveal some genetic secrets of evolution
Waiting for Breakthroughs "Nanoists" envision global abundance emerging from the manipulation of single atoms and molecules. But this prophecy has been challenged by researchers who work at a scale of billionths of a meter
The Amateur Scientist The New Backyard Seismology
Mathematical Recreations How Fair Is Monopoly?
Mar 1996
Urban Planning in Curitiba A Brazilian city challenges conventional wisdom and relies on low technology to improve the quality of urban life
Collisions with Comets and Asteroids The chances of a celestial body colliding with the earth are small, but the consequences would be catastrophic
The African AIDS Epidemic In parts of sub-Saharan Africa, nearly 25 percent of the population is HIV-positive as a result of heterosexual transmission of the virus. Could lack of circumcision make men in this region particularly susceptible?
Budding Vesicles in Living Cells A transatlantic collaboration has uncovered the machinery responsible for forming the tiny but essential containers, or vesicles, that store proteins and shuttle them to and fro in cells
The Art and Science of Photoreconnaissance In the 1950s and 1960s, photointerpreters devised ways of extracting valuable information from recondite images. Oftentimes, their work profoundly affected international relations
Electrons in Flatland Trapped in a two-dimensional plane, electrons can exhibit the quantum Hall effect, a startling phenomenon now thought to be intimately connected to superconductivity
Caribbean Mangrove Swamps Despite their ubiquity and prominent position between land and sea, these tropical ecosystems still hold countless surprises for researchers
Vital Data The Human Genome Project is producing a plethora of information that will illuminate our hidden susceptibilities to disease. The effort could transform medical science. But new dangers are arriving, too
The Amateur Scientist Exploring Chemical Bonds
Mathematical Recreations Playing with Quads and Quazars
Feb 1996
Malnutrition, Poverty and Intellectual Development Research into childhood nutrition reveals that a poor diet influences mental development in more ways than expected. Other aspects of poverty exacerbate the effects
The Global Positioning System Two dozen satellites hovering thousands of miles out in space are allowing people to locate themselves on the earth's surface with remarkable precision
Seeing Underwater with Background Noise With a technique called acoustic-daylight imaging, sounds in the sea can "illuminate" submerged objects, thereby creating moving color pictures without sonar
Telomeres, Telomerase and Cancer An unusual enzyme called telomerase acts on parts of chromosomes known as telomeres. The enzyme has recently been found in many human tumors and is being eyed as a new target for cancer therapy
Colossal Galactic Explosions Enormous outpourings of gas from the centers of nearby galaxies may ultimately help explain both star formation and the intergalactic medium
The Bacteria behind Ulcers One half to one third of the world's population harbors "Helicobacter pylori", "slow" bacteria that infect the stomach and can cause ulcers and cancer there
The Loves of the Plants Carl Linnaeus classified plants according to their reproductive parts, endowing them as well with sex lives reflecting 18th-century values and controversies
Quarks by Computer Yearlong computations have helped to confirm the fundamental theory behind quarks - and, using its principles, even to identify a new particle
The Amateur Scientist Growing Seedlings at Less Than 1 G
Mathematical Recreations Proof of Purchase on the Internet
Jan 1996
The Real Threat of Nuclear Smuggling Although many widely publicized incidents have been staged or overblown, the dangers of even a single successful diversion are too great to ignore
Caloric Restriction and Aging Eat less, but be sure to have enough protein, fat, vitamins and minerals. This prescription does wonders for the health and longevity of rodents. Might it help humans as well?
Technology and Economics in the Semiconductor Industry Although the days of runaway growth may be numbered, their passing may force chipmakers to offer more variety
Neural Networks for Vertebrate Locomotion The motions animals use to swim, run and fly are controlled by specialized neural networks. For a jawless fish known as the lamprey, the circuitry has been worked out
Cleaning Up the River Rhine Intensive international efforts are reclaiming the most important river in Europe
The Evolution of Continental Crust The high-standing continents owe their existence to the earth's long history of plate-tectonic activity
Working Elephants They earn their keep in Asia by providing an ecologically benign way to harvest forests
Explaining Everything A new symmetry, duality, is changing the way physicists think about fundamental particles - or strings. It is also leading the way to a Theory of Everything
The Amateur Scientist Recording Nature's Sounds
Mathematical Recreations Mother Worm's Blanket
Dec 1995
The Galileo Mission From orbit around Jupiter, the Galileo spacecraft will take the closest look ever at the planet and its natural satellites
Cystic Fibrosis The genetic defects underlying this lethal disease have now been shown to eliminate or hobble a critical channel through which a constituent of salt enters and leaves cells
Science in Pictures The Leaning Tower of Pisa The famous tower has been tilting since the 12th century. Now engineers are using 20th-century technology in hopes of saving the ancient landmark
Giant Earthquakes of the Pacific Northwest The danger of a very large earthquake striking the coast between northern California and British Columbia proves much greater than suspected
How Breast Milk Protects Newborns Some of the molecules and cells in human milk actively help infants stave off infection
The Puzzle of Conscious Experience Neuroscientists and others are at last plumbing one of the most profound mysteries of existence. But knowledge of the brain alone may not get them to the bottom of it
Confidential Communication on the Internet Cryptography gives people the ability to authenticate the identity of their correspondents, the first step in establishing trust
Trends in Defense Technology U.S. military planners hope to rely on improved versions of the technologies tested in the Gulf War to help fight the next Saddam Hussein. They may be preparing for the wrong conflict
The Amateur Scientist Measuring the Metabolism of Small Organisms
Mathematical Recreations The Anthropomurphic Principle
Nov 1995
The World's Imperiled Fish Wild fish cannot survive the onslaught of modern industrial fishing. The collapse of fisheries in many regions shows the danger plainly
The Brain's Immune System It consists of cells called microglia that are normally protective but can be surprisingly destructive. The cells may contribute to neurodegenerative diseases and to the dementia of AIDS
Chaotic Climate Global temperatures have been known to change substantially in only a decade or two. Could another jump be in the offng?
Holographic Memories After more than 30 years, researchers are on the verge of using holograms to store data in memories that are both fast and vast
Charles Darwin This newly rediscovered photograph appears to be the last ever made of the great evolutionist
God's Utility Function Humans have always wondered about the meaning of life. According to the author, life has no higher purpose than to perpetuate the survival of DNA
The Discovery of X-rays One hundred years ago this month, Wilhelm Conrad Röntgen cast the first x-ray images by chance
The Science of Juggling Studying the ability to toss and catch balls and rings provides insight into human coordination, robotics and mathematics
The Amateur Scientist Measuring the Wind with Hot Metal
Mathematical Recreations Ways to Tile Space with Knots
Oct 1995
Emerging Viruses Hemorrhagic fever viruses are among the most dangerous biological agents known. New ones are discovered every year, and artificial as well as natural environmental changes are favoring their spread
Companions to Young Stars The surprising finding that even the youngest stars commonly exist in sets of two or three has revised thinking about the birth of star systems
Quantum-Mechanical Computers Quantum-mechanical computers, if they can be constructed, will do things no ordinary computer can
Demolition by Implosion Detonation of small quantities of strategically placed explosives can demolish an unwanted high-rise in a matter of seconds
The Molecular Logic of Smell Mammals can recognize thousands of odors, some of which prompt powerful responses. Recent experiments illuminate how the nose and brain may perceive scents
Science in Pictures The raw visual and textual evidence of his imagination, Edison's notebooks were the unrevealed talismans of the inventor's career
Can Environmental Estrogens Cause Breast Cancer? The authors of a provocative hypothesis spell out their reasons for suspecting that hormone-mimicking chemicals in the environment contribute to many unexplained cases of breast cancer
Trends in Social Science Psychologists and others try to sidestep old pitfalls - both political and scientific - as they apply evolutionary theory to the clothed ape
Mathematical Recreations The Never-Ending Chess Game
Sep 1995
The Uncertainties of Technological Innovation Even the greatest ideas and inventions can flounder, whereas more modest steps forward sometimes change the world
Information Technologies Table of Content Faster, more sophisticated data networks and computers will dominate the systems people use to work and play. Meanwhile intelligence will become a feature of everyday machines. NOTE: No text.
Microprocessors in 2020 Every 18 months microprocessors double in speed. Within 25 years, one computer will be as powerful as all those in Silicon Valley today
Wireless Networks In the decade ahead, they will deliver personalized communications to people on the go and basic service to many who still lack telephones
All-Optical Networks Fiber Optics will become more efficient as light waves replace electrons for processing signals in communications networks
Artificial Intelligence A crucial storehouse of commonsense knowledge is now taking shape
Intelligent Software Programs that can act independently will ease the burdens that computers put on people
Virtual Reality VR will transform computers into extensions of our whole bodies
Satellites For a Developing World Satellites could provide universal access to the information economy
Transportation Opener Huge flying-wing aircarft, magnetically levitated trains and driverless cars may carry passengers to their destinations, while tiny spacecraft explore the solar system. NOTE: No text.
High-Speed Rail: Another Golden Age Neglected in North America but nurtured in Europe and Japan, high-speed rail systems are a critical complement to jets and cars
The Automobile: Clean and Customized Built-in intelligence will let automobiles tune themselves to their drivers and cooperate to get through crowded traffic systems safely
Evolution of the Commercial Airliner Advances in materials, jet engines and cockpit diplays could translate into less expensive and safer air travel
21st-Century Spacecraft A fleet of cheap, miniaturized spacecraft may revive the stalled Space Age, exploring the myriad tiny bodies of the solar system
Why Go Anywhere? Millions of people could be liberated from their vehicles
Medicine Opener Many diseases may be cured with gene therapy, and damaged organs may be repaired or replaced with tissue grown from cells in the laboratory. The new century should also see innovative contraceptives, including, finally, some for men. NOTE: No text.
Gene Therapy Several hundred patients have already received treatment. In the next century the procedure will be commonplace.
Artificial Organs Engineering artificial tissue is the natural successor to treatments for injury and disease. But the engineers will be the body's own cells
Future Contraceptives Vaccines for men and women will eventually join new implants, better spermicides and stronger, thinnner condoms
An Improved Future? Medical advances challenge thinking on living, dying and being human
Machines, Materials and Manufacturing Buildings that repair themselves, machines that fit on the head of a pin and local factories that make products to order are just some of the possibilities. NOTE: No text.
Self-Assembling Materials The smaller, more complex machines of the future cannot be built with current methods: they must almost make themselves
Engineering Microscopic Machines Electronic fabrication processes can produce a data storage device or a chemical factory on a microchip
Intelligent Materials Inspired by nature, researchers are creating substances that can anticipate failure, repair themselves and adapt to the environment
Advanced Composites After they first appeared in the 1960s, advanced composite materials promised a brave new - not to mention light and durable - future.
High-Temperature Superconductors They conduct current without resistance more cheaply than conventional superconductors can and are slowly finding their way to widespread use
Robotics in the 21st Century Automatons may soon find work as subservient household help
Energy and Environment The most crucial changes will come from attacking the waste problems of industry, agriculture and energy production at a fundamental level. NOTE: No text.
Solar Energy Technology will allow radiation from the sun to provide nonpolluting and cheap fuels, as well as electricity
Fusion Energy derived from fused nuclei may become widely used by the middle of the next century
Disposing of Nuclear Waste At 3:49 P.M. on December 2, 1942, in a converted squash court under the football stands at the University of Chicago, a physicist slid back some control rods in the first nuclear reactor and ushered in a new age.
The Industrial Ecology of the 21st Century A clean and efficient industrial economy would mimic the natural world's ability to recycle materials and minimize waste
Technology for Sustainable Agriculture The next green revolution needs to be sophisticated enough to increase yields while also protecting the environment
Outline For an Ecological Economy Countries can indeed prosper while protecting their environment
Living with New Technologies Technology will not solve all our problems. It may even create some. But, despite its shortcomings, it continues to offer us ever more ways to work, play, and order our lives. NOTE: no text.
Technology Infrastructure Industrial advances will depend on setting new standards
Designing the Future Too frequently, product designers disregard the psychology of the user
Digital Literacy Multimedia will require equal facility in word, image and sound
The Information Economy How much will two bits be worth in the digital marketplace?
The Emperor's New Workplace Information technology evolves more quickly than behavior
What Technology Alone Cannot Do Technology will not provide us all with health, wealth and big TVs
Mathematical Recreations The Great Drain Robbery
Aug 1995
Recollections of a Nuclear War Two nuclear bombs were dropped on Japan 50 years ago this month. The author, a member of the Manhattan Project, reflects on how the nuclear age began and what the post-cold war future might hold
Tornadoes The storms that spawn twisters are now largely understood, but mysteries still remain about how these violent vortices form
How HIV Defeats the Immune System A plausible hypothesis suggests the immune devastation that underlies AIDS stems from continuous - and dangerous - evolution of the human immunodeficiency virus in the body
The Benefits of Background Noise Stochastic resonance, the phenomenon by which background noise boosts weak signals, is creating a buzz in physics, biology and engineering
The Physiology of Decompression Illness For more than a century, researchers have known that exposure to high pressure can injure or kill. Gradually, they are beginning to understand the underlying mechanisms
Frog Communication In striving to be heard by rivals and mates, these amphibians have evolved a plethora of complex strategies
Comet Shoemaker-Levy 9 Meets Jupiter Images of a comet that broke apart and plummeted into Jupiter continue to dazzle astronomers a year afterward
Trends: Lost Science in the Third World Many researchers in the developing world feel trapped in a vicious circle of neglect and - some say - prejudice by publishing barriers they claim doom good science to oblivion
The Amateur Scientist Detecting Signals with Noise
Jul 1995
The Problematic Red Wolf Is the red wolf a species or a long-established hybrid of the gray wolf and the coyote? Such distinctions may affect ongoing efforts to save a variety of endangered species
Protecting the Greenback Digital color systems can reproduce paper money with disconcerting accuracy. The U.S. government's response is a new series of notes
Treating Diabetes with Transplanted Cells The implants, islet cells of the pancreas, can potentially cure many cases of diabetes. A prime obstacle to wide use - lack of a safe way to avoid immune attacks on the grafts - now seems to be crumbling
Light in the Ocean's Midwaters Beneath the surface of the ocean, sunlight is gradually extinguished, but the resulting darkness yields to a host of bioluminescent creatures
Light in the Ocean's Midwaters Fish such as hake, as well as some squids, arefast-moving, wide-ranging predators, but they often linger near Ventana, attracted to the lights of the ROV.
The Trebuchet Recent reconstructions and computer simulations reveal the operating principles of the most powerful weapon of its time
Cookstoves for the Developing World Traditional wood, charcoal and coal stoves are used in hundreds of millions of homes. Their redesign can have a dramatic effect on energy usage, the environment and community health
J. Robert Oppenheimer: Before the War Although Oppenheimer is now best remembered for his influence during World War II, he made many important contributions to theoretical physics in the 1930s
Plastics Get Wired/Trends in Material Science By tailoring the electrical properties of conducting polymers, researchers hope to render electronics a bit more organic
Mathematical Recreations Election Fever in Blockvotia
Jun 1995
Debt and the Environment Loans cause great human hardship, but their connection to ecological troubles is hard to prove
Building World-Record Magnets Packing the energy equivalent of a stick of dynamite, powerful electromagnets around the globe compete to advance our knowledge of materials science and physics
Hookworm Infection It retards growth and intellectual development in millions of children yet is largely ignored by researchers. New findings suggest excellent possibilities for a vaccine
The Arithmetics of Mutual Help Computer experiments show how cooperation rather than exploitation can dominate in the Darwinian struggle for survival
Deciphering a Roman Blueprint Scholarly detective work reveals the secret of a full-size drawing chiseled into an ancient pavement. The "blueprint" describes one of Rome's most famous buildings
Halo Nuclei Nuclei having excess neutrons or protons teeter on the edges of nuclear stability, known as drip lines. Under this stress, some develop a halo
Kin Recognition Many organisms, from sea squirts to primates, can identify their relatives. Understanding how and why they do so has prompted new thinking about the evolution of social behavior
TRENDS IN COMPLEXITY STUDIES: From Complexity to Perplexity Can science achieve a united theory of complex systems? Even at the Santa Fe Institute, some researchers have their doubts
The Amateur Scientist Computing Bouts of the Prisoner's Dilemma
May 1995
The Global Tobacco Epidemic Cigarette smoking has stopped declining in the U.S. and is rising in other parts of the world. Aggressive marketing and permissive regulations are largely to blame
Binary Neutron Stars These paired stellar remnants supply exquisite confirmations of general relativity. Their inevitable collapse produces what may be the strongest explosions in the universe
Dendrimer Molecules Chemists can now build fractal supermolecules. This new class of polymers promises to be valuable in biotechnology and environmental protection
The Ocean's Salt Fingers A small-scale oddity in the way seawater mixes can have large-scale consequences for the structure of the ocean
The Silicon Microstrip Detector Produced with the same tools used to create integrated circuits, these detectors recently helped to find the top quark and are central to other crucial experiments
The Atomic Intrigues of Niels Bohr Scandal is not usually linked with the name Niels Bohr; genius and character are.
Did Bohr Share Nuclear Secrets? Niels Bohr met with a Soviet agent in late 1945. Although some have accused Bohr of divulging nuclear secrets, a recently disclosed memo offers evidence to the contrary
What Did Heisenberg Tell Bohr about the Bomb? In 1941 Werner Heisenberg and Niels Bohr met privately in Copenhagen. Almost two years later at Los Alamos, Bohr showed a sketch of what he believed was Heisenberg's design for a nuclear weapon
The Preservation of Past Conservators are racing to save monuments threatened by development, pollution, looting and neglect. In the process, they are transforming the field of archaeology into a new science
Mathematical Recreations Fibonacci Forgeries
Apr 1995
The Puzzle of Declining Amphibian Populations The number of frogs, toads and salamanders is dropping in many areas of the world. The causes range from destruction of their local habitats to global depletion of the ozone layer
Quest for the Limits of the Heliosphere Four aging spacecraft are racing to the outer reaches of the solar system. Soon they may break through the last barriers to interstellar space
Machines That Learn from Hints Machine learning improves significantly by taking advantage of information available from intelligent hints
Understanding the Genetic Construction of Behavior Studies of courtship and mating in the fruit fly offer a window on the ways genes influence the execution of complex behaviors
The Art Historian's Computer Riddles posed by ancient works of art fall to historical analyses and electronic explorations
A Brief History of Infinity The infinite has always been a slippery concept. Even the commonly accepted mathematical view, developed by Georg Cantor, may not have truly placed infinity on a rigorous foundation
The Tapestry of Power in a Mesopotamian City Mashkan-shapir was for a brief time one of the most important cities in the civilized world. Its remains challenge traditional notions of power distribution in early urban society
The Price of Prevention Policymakers frequently suggest that preventive medicine pays for itself. In fact, studies now show that this claim is rarely true. Still, prevention is often a worthy health investment
The Amateur Scientist Computerized Restoration of Juvenile Art
Mar 1995
Faster Evaluation of Vital Drugs Traditional clinical trials may delay the availability of lifesaving therapies. Regulators now attempt to balance speed against the risk of errors
The Many Costs of Drug Testing When researchers test a new drug, pressures from many different constituencies coverage on the clinical trail.
Laser Control of Chemical Reactions For years, chemists have sought to control reactions with lasers - and have mostly failed. Success may come from exploiting subtle quantum effects resulting from the interaction of light and matter
An Efficient Swimming Machine Instinctive control of vortices lets fish swim the way they do. A robotic tuna has also managed it; boats and submarines may be next
The Genetic Basis of Cancer An accumulation of genetic defects can apparently cause normal cells to become cancerous and cancerous cells to become increasingly dangerous
Bonobo Sex and Society The behavior of a close relative challenges assumptions about male supremacy in human evolution
Protein-Based Computers Devices fabricated from biological molecules promise compact size and faster data storage. They lend themselves to use in parallel-processing computers, three-dimensional memories and neural networks
Environmental Degradation in Ancient Greece Contrary to the view that the ancients lived in harmony with their environment, archaeological and geologic evidence shows that they often abused the land
Seeking the Criminal Element Scientists are homing in on social and biological risk factors that they believe predispose individuals to criminal behavior. The knowledge could be ripe with promise - or rife with danger
Mathematical Recreations Turning the Tables Around
Feb 1995
Population, Poverty and the Local Environment As forests and rivers recede, a child's labor can become more valuable to parents, spurring a vicious cycle that traps families in poverty
Sonoluminescence: Sound into Light A bubble of air can focus acoustic energy a trillionfold to produce picosecond flashes of light. The mechanism eludes complete explanation
Molecular Machines That Control Genes The activities of our genes are tightly regulated by elaborate complexes of proteins that assemble on DNA. Perturbations in the normal operation of these assemblies can lead to diseases.
Manic-Depressive Illness and Creativity Does some fine madness plague great artists? Several studies now show that creativity and mood disorders are linked
Masers in The Sky Interstellar gas clouds produce intense, coherent microwaves. This radiation offers a glimpse of the size, content and distance of objects that may otherwise be invisible
The History of Synthetic Testosterone Testosterone has long been banned in sports as a performance-enhancing drug. This use may soon be accepted in medicine alongside other legitimate hormonal therapies
The Mid-Cretaceous Superplume Episode The earth has an erratic "heartbeat" that can release vast amounts of heat from deep within the planet. The latest "pulse" of the earth occurred 120 million years ago
Toward "Point One" Gigabit chips are now in the laboratory. But the critical technology needed for manufacturing smaller circuits confronts diminishing returns
The Amateur Scientist Producing Light from a Bubble of Air
Jan 1995
Ensuring the Longevity of Digital Documents The digital medium is replacing paper in a dramatic record-keeping revolution. But such documents may be lost unless we act now
The Prion Diseases Prions, once dismissed as an impossibility, have now gained wide recognition as extraordinary agents that cause a number of infectious, genetic and spontaneous disorders
Earth Before Pangea The North American continent may be more nomadic than any of its inhabitants
Elastic Biomolecular Machines Synthetic chains of amino acids, patterned after those in connective tissue, can transform heat and chemical energy into motion
The Oldest Old People in their late nineties or older are often healthier and more robust than those 20 years younger.
The Birth and Disease of Nova V1974 Cygni The brightest nova in 17 years answered many questions during its life and raised more in death
Egil's Bones An Icelandic saga tells of a Viking who had unusual, menacing features, including a skull that could resist blows from an ax. He probably suffered from an ailment called Paget's disease
Better Than a Cure The World Health Organization wants industry to step up its efforts to develop new vaccines. Can big business and a public health bureaucracy see eye to eye?
Mathematical Recreations Daisy, Daisy, Give Me Your Answer, Do
Dec 1994
Improving Automotive Efficiency Batteries and fuel cells? Cleaner air and reduced oil imports can be won by redesigning conventional internal-combustion-powered vehicles
Fossils of The Flaming Cliffs Mongolia's Gobi Desert contains one of the richest assemblages of dinosaur remains ever found. Paleontologists are uncovering much of the region's history.
Earth From Sky Radar systems carried aloft by the space shuttle Endeavour provide a new perspective of the earth's environment
The New Genetic Medicines Synthetic strands of DNA are being developed as drugs. Called antisense and triplex agents, they can potentially attack viruses and cancers without harming healthy tissue
The Duality in Matter and Light In quantum mechanics, objects can behave as particles or as waves. Studies now emphasize that such complementary features are more fundamental than has generally been appreciated
Making Environmental Treaties Work Many agreements aim to protect the global environment. But actually making them do so requires innovative approaches
Caulerpa This tropical alga is the world's largest single-celled organism. Yet it differentiates into a complex structure of leaves, stems and roots
Trends: The Speed of Write Scientists now transmit reports of their research - from first inspiration to final result - over electronic networks. Even live experiments can be witnessed on-line. Publishers and libraries may never be the same
The Amateur Scientist Measuring the Energy Drain on Your Car
Nov 1994
Cerebrospinal Meningitis Epidemics A debilitating and often deadly disease, meningitis remains common in many developing countries. New insights may soon enable us to predict and control outbreaks
The Self-Reproducing Inflationary Universe Recent versions of the inflationary scenario describe the universe as a self-generating fractal that sprouts other inflationary universes
The Genetics of Flower Development Flower cells learn which organs to become from genes that convey positional information. A model based on just half a dozen such genes can predict how mutations will affect floral structure
Sci Pixs: Escher's Metaphors The prints and drawings of M.C. Escher give expression to abstract concepts of mathematics and science
Secure Distributed Computing Networks and computer security often do not go well together, but the developers of the Athena system have yet to see their protocols fail
Why Children Talk to Themselves Although children are often rebuked for talking to themselves out loud, doing so helps them control their behavior and master new skills
Resolving Zeno's Paradoxes For millennia, mathematicians and philosophers have tried to refute Zeno's paradoxes, a set of riddles suggesting that motion is inherently impossible. At last, a solution has been found
Big-Time Biology Molecular biology is - not so quietly - evolving from a science into an industry. Can it survive the transformation?
Mathematical Recreations Playing Chess on a Go Board
Oct 1994
Life in the Universe We comprehend the universe and our place in it. But there are limits to what we can explain at present. Will research at the boundaries of science reveal a special role for intelligent life?
The Evolution of the Universe Some 15 billion years ago the universe emerged from a hot, dense sea of matter and energy. As the cosmos expanded and cooled, it spawned galaxies, stars, planets and life
The Earth's Elements The elements that make up the earth and its inhabitants were created by an earlier generation of stars
The Evolution of the Earth The formation of this planet and its atmosphere gave rise to life, which shaped the earth's subsequent development. Our future lies in interpreting this geologic past
The Origin of Life On Earth Growing evidence supports the idea that the emergence of catalytic RNA was a crucial early step. How that RNA came into being remains unknown
The Evolution of Life on the Earth The history of life is not necessarily progressive; it is certainly not predictable. The earths creatures have evolved through a series of contingent and fortuitous events
The Search for Extraterrestrial Life The earth remains the only inhabited world known so far, but scientists are finding that the universe abounds with the chemistry of life
The Emergence of Intelligence Language, foresight, musical skills and other hallmarks of intelligence are connected through an underlying facility that enhances rapid movements
Will Robots Inherit The Earth Yes, as we engineer replacement bodies and brains using nanotechnology. We will then live longer, possess greater wisdom and enjoy capabilities as yet unimagined
Sustaining Life On Earth Hope for an environmentally sustainable future lies in evolving institutions, technology and global concern
The Amateur Scientist Building an Electronic Neuron
Sep 1994
Disarming Lyme Disease Antibiotics are usually curative. A vaccine is in clinical trials. Next on the research agenda: how to help people suffering from chronic symptoms
Low-Energy Ways To Observe High-Energy Phenomena By observing interactions that are forbidden in the Standard Model, physicists can peek at supersymmetric and other happenings
The Aluminum Beverage Can Produced by the hundreds of millions every day, the modern can, robust enough to support the weight of an average adult, is a tribute to precision design and engineering
The Machinery of Cell Crawling When a cell crawls, part of its fluid cytoplasm briefly turns rigid. This transformation depends on the orderly assembly and disassembly of a protein scaffold
Solving The Paradox of Deep Earthquakes For decades, geophsicists have known that earthquakes should not occur at depth inside the earth. But they do. Finally, we know how and why these events happen
Privatizing Public Research With the end of the cold war, national defense has given way to international competitiveness as the theme for federal support of research. As it now stands, the idea will probably not work well
The Scientific Importance of Napoleon's Egyptian Campaign Bonaparte's invasion of Egypt brought French scientists and engineers to the Nile. Their work, in turn, brought the splendors of the Nile to Europe
Trends in Computing: Software's Chronic Crisis Despite 50 years of progress, the software industry remains years - perhaps decades - short of the mature engineering discipline needed to meet the demands of an information-age society
Mathematical Recreations A Subway Named Turing
Aug 1994
Third World Submarines The proliferation of submarines may be a threat to established navies and regional stability, but to arms manufacturers it is a market opportunity
Extreme Ultraviolet Astronomy Observations at these wavelengths, once thought impossible, are extending knowledge of the cosmos
Confocal Microscopy For producing sharp two- or three-dimensional images with light,this microscopic technique is unsurpassed. It can also be applied for seeing deep inside the tissues of living specimens
Squids (for superconducting quantum interference devices) are the most sensitive detectors of magnetic fields. Their applications range from diagnosis of brain tumors to tests of relativity
How Cells Produce Antigens Cells alert the immune system to the presence of infections by displaying molecular complexes made from bits of their own proteins and those of invading organisms
Red Tides Many experts believe these blooms of toxic algae have recently become more prevalent, posing a greater threat to human and marine health
The Eloquent Bones of Abu Hureya The daily grind in an early Near Eastern agricultural community left revealing marks on the skeletons of the inhabitants
Trends In Women's Health: A Global View Improving women's health means overhauling attitudes toward sex and addressing hidden epidemics, such as domestic violence
The Amateur Scientist Scanning Underwater Surfaces
Jul 1994
Agriculture for Developing Nations The capital-intensive, highly mechanized Western model may not suit every developing region. Systems of intensive polyculture, exemplified by rice cultivation, may be better
The Scientific Legacy of Apollo The retrieved lunar rocks have helped settle questions about the moon's origin, its composition and even the early conditions that affected life on the earth
Synthetic Self-Replicating Molecules Molecules crafted in the laboratory can make copies of themselves, "mutate," compete for resources and assemble, giving a paradigm for life
Barriers to Drug Delivery in Solid Tumors Many tumors resist full penetration by anticancer agents. Such resistance may help explain why drugs that eradicate tumor cells in laboratory dishes often fail to eliminate malignancies in the body
Manatees These giant aquatic grazers outchewed their rivals in the New World. Now humans, their sole enemy, hold the key to their survival
Jean Henri Fabre This reclusive entomologist became one of the most popular educational authors of his day. A look at his greatest work reveals both the underappreciated achievements and the failings of his science
Late Ice Age Hunting Technology Cro-Magnon artisans designed many kinds of spearpoints. By re-creating these weapons, we can better appreciate the sophisticated skill ancient hunters possessed
Trends: In Neuroscience What is consciousness? Can neurobiology explain it, or - as some philosophers argue - does this most elusive and inescapable of all phenomena lie beyond experiment's reach?
Mathematical Recreations The Ultimate in Anty-Particles
Jun 1994
Was The Race To The Moon Real? In 1961 President John F. Kennedy made the goal to be first on the moon a matter of national honor. But were the Soviets truly in the running?
The Classical Limit of an Atom By creating ultralarge atoms, physicists hope to study how the odd physics of the quantum world becomes the classical mechanics of everyday experience
Emotion, Memory and the Brain The neural routes underlying the formation of memories about primitive emotional experiences, such as fear, have been traced
Adaptive Optics Technology developed during the cold war is giving new capabilities to ground-based astronomical telescopes
Early Andean Cities Some 3,800 years ago Pampa de las Llamas-Moxeke and Taukachi-Konkan were carefully laid-out urban centers that housed many hundreds of people
The Sensory Basis of the Honeybee's Dance Language Novel experiments, such as training bees to respond to sounds and recruiting them using a robot, have ended several debates surrounding the dance language
The Ethnobotanical Approach to Drug Discovery Medicinal plants discovered by traditional societies are proving to be an important source of potentially therapeutic drugs
Grading the Gene Tests From just a snippet of DNA, geneticists can sometimes forecast a patient's health. But ethical problems surrounding this testing are as ominous as the diseases themselves.
The Amateur Scientist Genetically Altering Escherichia coli
May 1994
Evidence for a Biological Influence in Male Homosexuality Two pieces of evidence, a structure within the human brain and a genetic link, point to a biological component for male homosexuality
The Biological Evidence Challenged Even if genetic and neuroanatomical traits turn out to be correlated with sexual orientation, causation is far from proved
Bohm's Alternative to Quantum Mechanics This theory, ignored for most of the past four decades, challenges the probabilistic, subjectivist picture of reality implicit in the standard formulation of quantum mechanics
How Interferons Fight Disease They are not the cure-alls researchers once hoped they would be, but they are providing therapy for a variety of infectious illnesses and for some cancers
Chesley Bonestell's Astronomical Visions This artist's unique combination of technical knowledge and graphic prowess brought astronomy alive and helped to advance the manned spaceflight program
Directional Drilling New techniques enable crews to drill around natural or man-made obstructions for oil and gas. These same methods are used to sample underground pollutants and bury service lines
East Side Story: The Origin of Humankind The Rift Valley in Africa holds the secret to the divergence of hominids from the great apes and to the emergence of human beings
Aging Airways The FAA struggles to replace its winking, blinking air-traffic control equipment. But will the skies be safer? Can the agency survive the effort intact?
Mathematical Recreations How Many Guards in the Gallery?
Apr 1994
Trade, Jobs and Wages Blaming foreign competition for U.S. economic ills is ineffective. The real problems lie at home
Charge and Spin Density Waves Electrons in some metals arrange into crystalline patterns that move in concert, respond peculiarly to applied voltages and show self-organization
Visualizing the Mind Strategies of cognitive science and techniques of modern brain imaging open a window to the neural systems responsible for thought
Chemistry and Physics in the Kitchen Bon appétit! Scientists are beginning to understand how chefs accomplish their culinary masterpieces and are making modest recipe suggestions of their own
The Dilemmas of Prostate Cancer Do the risks of aggressive treatment for early prostate cancer outweigh the benefits? This question is one of several unresolved issues faced by those who treat, and those who have, prostate cancer
Precious Metal Objects of the Middle Sican A Peruvian culture older than the Incas made unprecedented use of gold and other metals. Studies of Sicán metalworking techniques offer hints about this mysterious society
The Pioneer Mission to Venus This multipart spacecraft spent 14 years scrutinizing the atmosphere, clouds and environs of the nearest planet. The results clarify the stunningly divergent evolutionary histories of Venus and the earth
Trends In Biological Restoration Can we rebuild it? The field of ecological restoration is evaluating techniques to restore nature and is grappling with definitions of success
The Amateur Scientist The Kitchen as a Lab
Mar 1994
Can the Growing Human Population Feed Itself? As human numbers surge toward 10 billion, some experts are alarmed, others optimistic. Who is right?
The Earth's Mantle Below The Oceans Samples collected from the ocean floor reveal how the mantles convective forces shape the earths surface, create its crust and perhaps even affect its rotation
Targeted Gene Replacement Researchers can now create mice bearing any chosen mutations in any known gene. The technology is revolutionizing the study of mammalian biology
High-Speed Silicon-Germanium Electronics The author has helped create electronic devices that outperform traditional silicon technology yet remain compatible with standard manufacturing methods
The Quantum Physics of Time Travel Common sense may rule out such excursions - but the laws of physics do not
The Dynamics of Social Dilemmas Individuals in groups must often choose between acting selfishly or cooperating for the common good. Social models explain how group cooperation arises - and why that behavior can suddenly change
Frogs and Toads in Deserts Amphibians seem unlikely desert denizens. But those living in dry climes reveal a diverse and unusual array of adaptations to life at the extremes
Wire Pirates Consumers and entrepreneurs crowd onto the information highway, where electronic bandits and other hazards await them
Mathematical Recreations The New Merology of Beastly Numbers
Feb 1994
The Future of American Defense U.S. forces were shaped for conflict with a superpower. The emerging multilateral world calls for a smaller, more flexible and far less expensive military
Sulfate Aerosol and Climatic Change Industrial emissions of sulfur form particles that may be reflecting solar radiation back into space, thereby masking the greenhouse effect over some parts of the earth
The Molecular Architects of Body Design Putting a human gene into a fly may sound like the basis for a science fiction film, but it demonstrates that nearly identical molecular mechanisms define body shapes in all animals
When Is Seeing Believing? Digital technology for manipulating images has subverted the certainty of photographic evidence
Liquid Mirrors Light, liquid-mercury mirrors, which can potentially be made much larger than glass mirrors, may enable astronomers to construct enormous telescopes and see farther than ever before
AIDS and the Use of Injected Drugs The AIDS epidemic continues to grow among drug users who inject. It could be curbed if governments more readily adopted effective prevention programs
The Terror Birds of South America These huge, swift creatures were the dominant carnivores of the continent for millions of years, until competitors drove them into extinction
Particle Metaphysics In the aftermath of the Superconducting Super Collider's death, physicists are divided over how - or even whether - they should continue their search for a unified theory of nature
The Amateur Scientist Making a Mirror by Spinning a Liquid
Jan 1994
Wetlands These havens of biodiversity are often endangered because they can be hard to identify. Understanding their variable characteristics can lead to more successful conservation efforts
The Search for Strange Matter Between nucleus and neutron star stretches a desert devoid of nuclear matter. Could strange quark matter fill the gap?
The Toxins of Cyanobacteria These poisons, which periodically and fatally contaminate the water supplies of wild and domestic animals, can also harm humans. But they are being coaxed into doing good
Breaking Intractability Problems that would otherwise be impossible to solve can now be computed, as long as one settles for what happens on the average
Animal Sexuality Animals have evolved a range of mechanisms to determine whether an individual takes on masculine or feminine traits. Cross-species comparisons offer some surprising insights into the nature of sexuality
World Linguistic Diversity The ancestor of each language was taken to its current territory by pioneers, farmers, traders or a conquering elite. Multidisciplinary studies are clarifying their respective roles
The First Data Networks The optical telegraph is almost forgotten. Two centuries ago it moved messages over hundreds of kilometers in a few minutes
Trends: A War Not Won Despite dramatic scientific gains, cancer remains an undaunted killer
Mathematical Recreations Knots, Links and Videotape
Dec 1993
The Fertility Decline in Developing Countries Family size is decreasing in many Third World countries. The reasons provide the key to slowing population growth
The Compton Gamma Ray Observatory A steady stream of data from this orbiting observatory is painting a portrait of a dynamic and often enigmatic cosmos
MHC Polymorphism and Human Origins The diversity of human tissue types was generated long before Homo sapiens emerged
Africanized Bees in the U.S. Africanized honeybees have reached the U.S. from points south. As more of them arrive, they will certainly wreak some havoc but perhaps not the type their "killer bee" nickname would imply
Drugs by Design Structure-based design, an innovative approach to developing drugs, has recently spawned many promising therapeutic agents, including several now in human trials for treating AIDS, cancer and other diseases
Coupled Oscillators and Biological Synchronization A subtle mathematical thread connects clocks, ambling elephants, brain rhythms and the onset of chaos
The Death Cults of Prehistoric Malta New archaeological excavations reveal that as the ancient island societies suffered from environmental decline, they developed an extreme religious preoccupation with life and death
Current Events Now that the blizzard of hype has stopped, workers are gradually realizing the promise of high-temperature superconductors
The Amateur Scientist Electronic Fireflies
Nov 1993
The Case for Free Trade Environmentalists are wrong to fear the effects of free trade. Both causes can be advanced by imaginative solutions
The Perils of Free Trade Economists routinely ignore its hidden costs to the environment and the community
Chemical Signaling in the Brain Studies of acetylcholine receptors in the electric organs of fish have generated critical insights into how neurons in the human brain communicate with one another
X-Ray Binaries In these systems, ultradense neutron stars feed on their more sedate companions. Such stellar cannibalism produces brilliant outpourings of x-rays and drastically alters the evolution of both stars
The Art of Boris Artzybasheff A compelling mid-20th century vision of the machines of war and peace
High-Power Electronics A new generation of silicon switches enables power grids to meet the needs of utility customers with high efficiency and reliability
Ancient DNA Genetic information that had seemed lost forever turns out to linger in the remains of long-dead plants and animals. Evolutionary change can at last be observed directly
Trends in the Sociology of Science Despite decades of struggle, women retain a small minority in the scientific commmunity
Mathematical Recreations Fermat's Last Time-Trip
Oct 1993
Clearing the Air in Los Angeles Although Los Angeles has the most polluted skies in the nation, it is one of the few cities where air quality has improved in recent decades
Large Igneous Provinces These vast fields of lava record powerful but geologically brief pulses of magmatic activity. Their formation may have triggered significant changes in the global environment
Evolutionarily Mobile Modules in Proteins Many proteins consist of a fairly small set of modular elements. How these units spread and multiplied during evolution is not altogether clear, but a pattern may be emerging
Electrorheological Fluids Some liquids solidify instantly when exposed to an electric field. Such protean materials may give engineers quicker, more adaptive machines
Water-Pollinated Plants Once thought to be mere aberrations of nature, these flowering aquatic species provide evidence for the evolutionary convergence toward efficient pollination strategies
Simulating Brain Damage Adults with brain damage make some bizarre errors when reading words. If a network of simulated neurons is trained to read and then is damaged, it produces strikingly similar behavior
Raising the Vasa This Swedish man-of-war foundered on her maiden voyage and slept for three centuries at the bottom of Stockholm Harbor. Here is the story of her resurrection
The Death of Proof Computers are transforming the way mathematicians discover, prove and communicate ideas, but is there a place for absolute certainty in this brave new world?
The Amateur Scientist Making Fluids into Solids with Magnets
Sep 1993
Life, Death and the Immune System By defining and defending the self, the immune system makes life possible; malfunction causes illness and death. Study of the system provides a unifying view of biology
How the Immune System Develops Environmental and genetic signals cue cells as they differentiate into the many lineages that recognize foreign antigens and fight off invaders
How the Immune System Recognizes Invaders Cells of the immune system recombine gene fragments to create the millions of receptors needed to identify and attack the myriad pathogens encountered throughout life
How the Immune System Recognizes the Body The human immune system has developed several elegant processes that allow it to repel foreign invaders and yet not attack the body itself
Infectious Diseases and the Immune System When bacteria, viruses and other pathogens infect the body, they hide in different places. Each component of the immune system is most adept at rousting trespassers from one location
AIDS and the Immune System The AIDS virus exploits the immune system to replicate itself. New findings are showing how it wreaks havoc on the body's defenses
Autoimmune Disease Misguided assaults on the self produce multiple sclerosis, juvenile diabetes and other chronic illnesses. Promising therapies are emerging
Allergy and the Immune System In allergic individuals, parts of the immune system misdirect their power at innocuous substances, producing sometimes deadly symptoms
The Immune System as a Therapeutic Agent New technologies and insights into the molecular underpinnings of the immune system provide the basis for novel approaches to vaccines and other therapies
Will We Survive? As host and pathogen evolve together, will the immune system retain the upper hand?
Mathematical Recreations A Shepherd Takes a Sheep Shot
Aug 1993
Eliminating Nuclear Warheads More than 50,000 nuclear weapons may be decommissioned during the next 10 years. Their disposal requires both technical and political innovations
Faster than Light? Experiments in quantum optics show that two distant events can influence each other faster than any signal could have traveled between them
T Cell Anergy When cells of the immune system "see" antigens in the absence of the right cosignals, they shut themselves down instead of attacking. Future therapies might capitalize
A Universe of Color Color photography continues to be an important astronomical tool that reveals details of celestial objects not yet captured by modern electronic detectors
Mastering Chaos It is now possible to control some systems that behave chaotically. Engineers can use chaos to stabilize lasers, electronic circuits and even the hearts of animals
Diet and Primate Evolution Many characteristics of modern primates, including our own species, derive from an early ancestor's practice of taking most of its food from the tropical canopy
The Great Radium Scandal William J. A. Bailey grew rich from his radium-laced patent medicine until it killed a leading socialite. The scandal helped to usher in modern standards of radioisotope regulation
Trends in Communications A technophile vice president and the information, entertainment and communications industries have discovered the source of next generation electronic products - it's the network.
The Amateur Scientist Circuits That Get Chaos in Sync
Jul 1993
Risk Analysis and Management Inadequate approaches to handling risks may result in bad policy. Fortunately, rational techniques for assessment now exist
Viral Quasispecies The standard definition of a biological species does not apply to viruses. A more expansive and dynamic view of viral populations holds clues to understanding and defeating them
Australia's Polar Dinosaurs Their excellent night vision and apparent warm blood raise a question: Could they have survived icehouse conditions at the end of the Cretaceous period?
Accurate Measurement of Time Increasingly accurate clocks - now losing no more than a second over millions of years - are leading to such advances as refined tests of relativity and improved navigation systems.
Surgical Treatment of Cardiac Arrhythmias To save the life of a doomed patient, the author and his colleagues developed a now standard surgical procedure for correcting lethally fast heartbeats in many people susceptible to them
Fuzzy Logic The binary logic of modern computers often falls short when describing the vagueness of the real world. Fuzzy logic offers more graceful alternatives
Edwin Hubble and the Expanding Universe More than any other individual, he shaped astronomers' present understanding of an expanding universe populated by a multitude of galaxies
Sustaining the Amazon Can scientists reconcile the inevitability of economic development with the preservation of rain forests?
Mathematical Recreations The Topological Dressmaker
Jun 1993
Underground Records of Changing Climate Boreholes drilled into continental rock can recover fossil temperatures that reveal the climate of past eras. The results require careful interpretation
The Most Distant Radio Galaxies Astronomers have identified powerful radio emitting galaxies that existed when the universe was only one tenth its present age. These objects offer a glimpse at the early evolution of giant galaxies
The Centrosome By directing the assembly of a cell's skeleton, this organelle controls division, motility and shape. The details of its structure and function are just beginning to emerge
The Future of the Transistor As it has grown smaller and cheaper, engineers have scoffed at theoretical barriers to its progress - so far
Monogamy and the Prairie Vole Studies of the prairie vole - a secretive, mouselike animal - have revealed hormones that may be responsible for monogamous behavior
Autism Autistic individuals suffer from a biological defect. Although they cannot be cured, much can be done to make life more hospitable for them
The Great Well of China More than 150 years ago the Chinese drilled one kilometer into the earth to extract brine for making salt. The well was the culmination of an 800-year-old technology
Eugenics Revisited Scientists are linking genes to a host of complex human disorders and traits, but just how valid - and useful - are these findings?
Mathematical Recreations A Bundling Fool Beats the Wrap
May 1993
The Economics of Life and Death Mortality data can be used to analyze economic performance. Such information can illuminate critical aspects of the economic organization of society
The Core-Mantle Boundary This interactive zone may be the most dynamic part of the planet, directly affecting the earth's rotation and magnetic field.
How Cells Respond to Stress During emergencies, cells produce stress proteins that repair damage. Inquiry into how they work offers promise for coping with infection, autoimmune disease and even cancer
Intelligent Gels Soft aggregations of long-chain molecules can shrink or swell in response to stimuli. They may form the basis of a new kind of machine.
The Power of Maps The authoritative appearance of modern maps belies their inherent biases. To use maps intelligently, the viewer must understand their subjective limitations
The Neurobiology of Fear Researchers are beginning to tease apart the neurochemical processes that give rise to different fears in monkeys. The results may lead to new ways to treat anxiety in humans
P. A. M. Dirac and the Beauty of Physics He preferred the beautiful theory to the fact-buttressed ugly one because, as he noted, facts change. He proved his point by predicting the existence of antimatter.
Inconstant Cosmos Space-based telescopes endowed with x-ray and gamma-ray vision observe an ever restless, dynamic universe.
The Amateur Scientist Mapping to Preserve a Watershed
Apr 1993
The Aging of the Human Species Our species has modified the evolutionary forces that have always limited life expectancy. Policymakers must consequently prepare to meet the needs of a population that will soon be much older
Cavity Quantum Electrodynamics Atoms and photons in small cavities behave completely unlike those in free space. Their quirks illustrate some of the principles of quantum physics and make possible the development of new sensors
Listening with Two Ears Studies of barn owls offer insight into just how the brain combines acoustic signals from two sides of the head into a single spatial perception
Catalysis on Surfaces Scientists can now observe how solids interact with individual molecules to speed reactions. Information about these catalysts is being used to improve everything from materials synthesis to pollution control
The Reproductive Behavior of the Stickleback To reproduce, this tiny fish engages in behaviors not commonly associated with such animals, including luring intruders away and cannibalizing another's eggs
The Evolution of Virulence Human behavior appears to influence whether pathogens evolve into benign or harmful forms. Health policy should therefore include evolutionary considerations
Modern Humans in the Levant Modern Homo sapiens preceded Neanderthals on Mount Carmel and followed a similar pattern of life for 60,000 years. Biology thus cannot explain the cultural revolution that then ensued
Trends in Materials Rehabilitating the nation's aging infrastructure may depend on how well industry, government and academia tweak the properties of materials, from lowly concrete to aerospace composites
Mathematical Recreations The Rise and Fall of the Lunar M-pire
Mar 1993
Why America's Bridges are Crumbling Inadequate maintenance has piled up a repair bill that will take decades to pay off. Indeed, the scope of the problem is only now becoming clear
Black Holes and the Centrifugal Force Paradox An object orbiting close to a black hole feels a centrifugal force pushing inward rather than outward. This paradoxical effect has important implications for astrophysics
Teaching the Immune System to Fight Cancer Certain molecules on tumors can serve as targets for attack by cells of the immune system. These tumor-rejection antigens may provide a basis for precisely targeted anticancer therapy
Flat Panel Displays Recent advances in microelectronics and liquid crystals make possible video screens that can be hung on a wall or worn on a wrist.
How Parasitic Wasps Find Their Hosts Besides recognizing odors from their caterpillar hosts, wasps also learn to identify compounds released by the plant on which the caterpillars feed
Ice Age Lamps The invention of fat-burning lamps toward the end of the Ice Age helped to transform European culture. It coincided with several other major technological advances
Flooded Forests of the Amazon Parts of the vast rain forest are as much aquatic as terrestrial ecosystems. Unique adaptations allow creatures to thrive in these inundated woods
Trends in Genetics DNA'S New Twists The known rules of genetics are only the beginning. The newly discovered abilities of a familiar molecule are influencing theories about evolution and the inheritance of disease.
The Amateur Scientist Flight-Testing Fruit Flies
Feb 1993
Environmental Change and Violent Conflict Growing scarcities of renewable resources can contribute to social instability and civil strife
Resistance in High-Temperature Superconductors Researchers are beginning to see how the motion of magnetic vortices in these materials can interfere with the flow of current
Zinc Fingers They play a key part in regulating the activity of genes in many species, from yeast to humans. Fewer than 10 years ago no one knew they existed
How Should Chemists Think? Chemists can create natural molecules by unnatural means. Or they can make beautiful structures never seen before. Which should be their grail?
A Technology of Kinetic Art Delicate interplay of weights and balances choreographs the author's sculptures so that the gentlest gusts of air set their parts in motion
Breaching the Blood-Brain Barrier Development of a therapy for meningitis has revealed how bacteria penetrate the blood-brain barrier. This knowledge may help physicians treat other disorders of the brain
Redeeming Charles Babbage's Mechanical Computer A successful effort to build a working, three-ton Babbage calculating engine suggests that history has misjudged the pioneer of automatic computing
Trends in Russian Science Researchers in the Russian Federation are in desperate straits. Plummeting budgets and pitiful salaries are driving many to leave the country. Those who stay are being forced to become merchant adventurers.
Mathematical Recreations A Partly True Story
Jan 1993
Coral Bleaching Environmental stresses can cause irreparable harm to coral reefs. Unusually high seawater temperatures may be a principal culprit
How the Milky Way Formed Its halo and disk suggest that the collapse of a gas cloud, stellar explosions and the capture of galactic fragments may have all played a role
Carbohydrates in Cell Recognition Telltale surface sugars enable cells to identify and interact with one another. New drugs aimed at those carbohydrates could stop infection and inflammation
The Earliest History of the Earth Radioactive dating techniques have illuminated vast stretches of geologic history, bringing the most ancient eras of the earth's evolution into view
Madagascar's Lemurs These primates can tell us a great deal about our own evolutionary past. But many species are already extinct, and the habitats of those that remain are shrinking fast
Quantum Dots Nanotechnologists can now confine electrons to pointlike structures. Such "designer atoms" may lead to new electronic and optical devices
The Mind and Donald O. Hebb By rooting behavior in ideas, and ideas in the brain, Hebb laid the groundwork for modern neuroscience. His theory prefigured computer models of neural networks
Adapting To Complexity From a primeval sea of organic molecules arose plants, animals, global ecosystems, intelligent beings, international organizations. What drives the natural world toward complexity?
The Amateur Scientist Biodiversity in the Backyard

Compiled by Dave Lo, article summaries © Scientific American