Scientific American

From Bountiful to Barren: Rainfall Decrease Left the Sahara Out to Dry [News]

Fri, 09 May 2008 14:10:00 EST

In a finding that may help scientists better predict the pace of climate change, research published in Science shows how the Sahara Desert, a region as big as the U.S. that stretches from the Atlantic Ocean to the Red Sea across northern Africa, went from bountiful to bone-dry over a period of several thousand years.

Scientists peered into the Sahara's verdant past by analyzing sediment samples drilled out of the bottom of one of the desert's last living lakes. The samples revealed long-held secrets of how desert-friendly species replaced tropical plants and animals as monsoon rains retreated farther south into the continent.

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Mailbag: Is Fluoride Dangerous? Is a Solar Grand Plan a Good Idea? [Scientific American Magazine]

Fri, 09 May 2008 11:14:00 EST

Fluoride FindingsA report by the National Research Council (NRC) is cited as suggesting negative effects of fluoride in “Second Thoughts about Fluoride,” by Dan Fagin. But the NRC notes that its report was not initiated because of concerns about the low levels of fluoride used in community water fluoridation, nor did it examine that issue. Instead the report is part of a routine review by the Environmental Protection Agency to address whether the higher levels of naturally occurring fluoride currently allowed in drinking water pose a health risk. The EPA is evaluating the report.

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The Evolving Web of Future Wealth [Edit This]

Fri, 09 May 2008 10:25:00 EST

Editor's Note: Stuart Kauffman has a well-earned reputation as a scientific provocateur, albeit one with the weight of data and wisdom on his side. Kauffman, a complexity researcher and biologist of the University of Calgary and the Santa Fe Institute, has argued, for example, that self-organization--the propensity for systems to become more complex without outside guidance--was just as important as natural selection in shaping evolution. (Intelligent design advocates, take note.)

In his new book Reinventing the Sacred: A New View of Science, Reason, and Religion (Basic Books, New York; May 2008), Kauffman develops a larger argument: Understanding what's happening in complex systems could help modern science break free of what some consider its too-reductionistic underpinnings. One controversial idea that Kauffman develops in his book is that by failing to take this approach to economics, traditional economists are unable to explain something that seems obvious but isn't: How does innovation drive growth?

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Training Scientists to Run for Office [60-Second Science]

Fri, 09 May 2008 00:00:08 EST

[The following is an exact transcript of this podcast.]

Would America be a better place if more people with science training held elective office? One organization that thinks so is Scientists and Engineers for America, or SEA. On May 10th, they’re holding a day-long workshop in Washington, D.C., to teach researchers the nuts and bolts of running for office. More than 70 attendees have signed up. [More]

Legislation Introduced to Spur Treatments for Brain Ailments [News]

Thu, 08 May 2008 17:00:00 EST

Lawmakers yesterday introduced legislation designed to speed the development of new, safer therapies for brain and nervous system disorders and injuries, which affect an estimated 100 million Americans and costs an estimated $1.3 trillion annually to treat. [More]

Scientists Build Nano Hot Rods [News]

Thu, 08 May 2008 16:00:00 EST

Like a team of laboratory gearheads, Arizona State University (A.S.U.) researchers have found a way to soup up microscopic "nanomachines" that may someday be used to deliver lifesaving medications or test the quality of drinking water in remote regions of the world. In place of turbochargers and high-octane gas, the scientists tweaked their engine design and used an additive to speed the oxidation of hydrogen peroxide into fuel to create nanomachines 350 times more powerful than any previously built. [More]

To Catch a Plutonium Thief, Try Antineutrinos [News]

Thu, 08 May 2008 13:35:00 EST

A new more secure technology for guarding against theft from nuclear reactors has passed its first test.

Researchers from Lawrence Livermore National Laboratory and Sandia National Laboratories in Livermore, Calif., successfully monitored the power output of a relatively small nuclear power reactor by measuring the number of antineutrinos--ghostly particles generated by nuclear fission--that struck a refrigerator-size tank of liquid.

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What's Our Connection to the Platypus? [News]

Thu, 08 May 2008 13:00:00 EST

The platypus (Ornithorhynchus anatinus) is an odd-looking creature whose features combine the furry torso and wide, flat tail of a beaver with the rubbery bill and webbed feet of a duck. But its looks are not all that is strange about it. A new study indicates that the distinctive mammal's genetic code is an eclectic brew of bird, reptile and mammal. [More]

Whatever Happened to the Pioneer Spacecraft? [Scientific American Magazine]

Thu, 08 May 2008 11:08:00 EST

Mystery Cruise ControlThe velocities of Pioneer 10 and 11, now speeding out of the solar system, are mysteriously changing, as if an extra force from the sun were tugging at them. Explanations have ranged from gas leaks and observational error to modified theories of gravity [see “A Force to Reckon With”; SciAm, October 2005].

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An Uninsured Doctor in the House [Features]

Thu, 08 May 2008 11:00:00 EST

One of the first things U.S. Rep. Steve Kagen (D–Wisc.) did when he took office last year was to nix his congressional health care coverage. The move stunned a human resources staffer, who, the lawmaker says, looked at him as though he were insane.

"I'll respectfully decline until you can make that same offer for all of my constituents," he says he told her, explaining his decision to turn down what many say is the Cadillac of U.S. health plans.

[More]

Cloth-Eating Fungus Could Make Fuel [60-Second Science]

Thu, 08 May 2008 10:30:08 EST

Podcast Transcript: It sounds like something out of a bad science fiction novel. During World War II, a fungus called Tricoderma reesei ate its way through US military uniforms and tents in the South Pacific. It chewed up the cloth and used special enzymes to convert the indigestible cellulose into simple sugars. Now that infamous fungus is getting some good publicity. It looks like it might hold a key to improving the production of biofuels. [More]

Myanmar Cyclone: Before and After [Image Gallery]

Thu, 08 May 2008 00:00:00 EST

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Quake Shakes Tokyo [News]

Wed, 07 May 2008 18:00:00 EST

Japan was rocked by a series of earthquakes today about 100 miles (160 kilometers) from Tokyo that injured two, cut off power to some 2,100 homes, and left the country on high alert for possible aftershocks. The largest quake hit at 1:45 a.m. local time in the Pacific Ocean off the coast of the Ibaraki Prefecture and measured 6.8 on the Richter scale, but Japan's meteorological agency told the Agence France-Presse (AFP) that it does not expect the tremors to result in a tsunami. [More]

Evolution Enclaves: Darwin the Botanist and Origins of Life Research [Science Talk]

Wed, 07 May 2008 14:30:08 EST

David Kohn, curator of the Darwin's Garden exhibit at the New York Botanical Garden, discusses Darwin's botanical studies. And Harvard Medical School's Jack Szostak talks about research into the origins of life. Plus we'll test your knowledge of some recent science in the news. Websites mentioned on this episode include www.nybg.org/darwin; www.hhmi.org; www.sciam.com/daily

The text transcript is currently not available. Transcripts are posted about a week after the podcast airs.

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Are Personal Genome Scans Medically Useless? [Scientific American Magazine]

Wed, 07 May 2008 08:16:00 EST

For $1,000 and up, several new companies will scan an individual’s entire genome for clues about ancestry, potential health limitations and the inheritance of traits such as lactose intolerance. Clients can compare their DNA with a celebrity’s or invite friends and family members to share genetic profiles. Despite the comprehensive reports and background data these Web-based services deliver, some observers believe the information is more recreational than relevant.

Direct-to-consumer genetic tests have existed for at least a decade, and in recent years the number of choices has exploded. Whereas most of these offerings probe for only a small number of gene variants, advances in genome chips now allow a quick, inexpensive search for a wide range of targets all at once. Navigenics in Redwood Shores, Calif., 23andMe in Mountain View, Calif., and deCODE Genetics in Reykjavik, Iceland, recently began scanning for markers associated with as many as two dozen conditions and traits. And for upward of $350,000, Knome in Cambridge, Mass., enables customers to join J. Craig Venter and James D. Watson in the elite cadre of humans who have had their entire genome sequenced, analyzed and interpreted.

[More]

Virus Outbreak Shakes China [Sciam Observations Blog]

Wed, 07 May 2008 07:33:58 EST

Updated from a May 5 blog entryChinese health-care officials are scrambling to contain the outbreak of a contagious and sometimes deadly intestinal virus--known as Enterovirus 71 (EV71)--that has already claimed the lives of at least 28 children and is likely to continue spreading. [More]

Mind Control by Cell Phone [Mind Matters]

Wed, 07 May 2008 07:00:00 EST

Hospitals and airplanes ban the use of cell phones, because their electromagnetic transmissions can interfere with sensitive electrical devices. Could the brain also fall into that category? Of course, all our thoughts, sensations and actions arise from bioelectricity generated by neurons and transmitted through complex neural circuits inside our skull. Electrical signals between neurons generate electric fields that radiate out of brain tissue as electrical waves that can be picked up by electrodes touching a person's scalp. Measurements of such brainwaves in EEGs provide powerful insight into brain function and a valuable diagnostic tool for doctors. Indeed, so fundamental are brainwaves to the internal workings of the mind, they have become the ultimate, legal definition drawing the line between life and death.

Brainwaves change with a healthy person's conscious and unconscious mental activity and state of arousal. But scientists can do more with brainwaves than just listen in on the brain at work-they can selectively control brain function by transcranial magnetic stimulation (TMS). This technique uses powerful pulses of electromagnetic radiation beamed into a person's brain to jam or excite particular brain circuits.

[More]

Were Dinos on Their Way Out Before the Meteor? [60-Second Science]

Wed, 07 May 2008 00:00:08 EST

Podcast Transcript: It’s accepted that a large meteor impact 65 million years ago was responsible for the mass extinction of the dinosaurs. Which opened up niches for birds and mammals. But last week at an evolution conference at The Rockefeller University in New York City, New Zealand biologist David Penny questioned whether the dinosaurs might not have already been on their way out. [More]

New Twist on Nanowires [Image Gallery]

Wed, 07 May 2008 00:00:00 EST

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The Monitor, ep. 13--Colossal Squid, Narwhals and Improvisational Robotics [The Monitor]

Tue, 06 May 2008 17:15:00 EST

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Toasted Bugs? Tropical Insects May Not Thrive in Warming World [News]

Tue, 06 May 2008 16:20:00 EST

Global warming may prove worse for insects--and other cold-blooded critters--living in the steamy tropics than for their counterparts living closer to the frigid polar regions, according to a new study in Proceedings of the National Academy of Sciences USA. Even though climate change is likely to affect areas near the poles, tropical insects are already living in conditions that verge on being too hot for them, which means they could be teetering on the edge of extinction.

Take the shield bug--also known as the stinkbug for the nasty smelling liquid it spews when attacked. There are varieties of the insect in both the U.K. and Kenya. But although the shield bugs in the former may prosper as a result of a warmer climate in their region, their counterparts in Kenya (and other parts of Africa) may find themselves unable to cope with the heat, according to the research--and, if they cannot adapt or move, they may perish. "The current climate is at its optimum temperature," says study co-author and biogeochemist Curtis Deutsch of the University of California, Los Angeles. "Any warming was going to push them towards reduced fitness."

[More]

Can You Catch Up on Lost Sleep? [Fact or Fiction]

Tue, 06 May 2008 13:10:00 EST

Let's do some sleep math. You lost two hours of sleep every night last week because of a big project due on Friday. On Saturday and Sunday, you slept in, getting four extra hours. Come Monday morning, you were feeling so bright-eyed, you only had one cup of coffee, instead of your usual two. But don't be duped by your apparent vim and vigor: You're still carrying around a heavy load of sleepiness, or what experts call "sleep debt"--in this case something like six hours, almost a full nights' sleep. [More]

Chile Volcano Eruption Sends Residents Fleeing, Causes One Death [News]

Tue, 06 May 2008 12:45:00 EST

Lava began to flow today from Chile's Chaitén volcano, chasing remaining residents out of a nearby town and putting the government of the affected Palena Province on high alert. The country had already been on edge following the volcano's initial eruption this past weekend, spewing hot ash, gas and smoke into the air for several days, forcing the evacuation of more than 4,200 residents and leading to the death of a 92-year-old woman who suffered a heart attack aboard a navy boat as she was being taken to Puerto Montt, about 125 miles (200 kilometers) north of the volcano. No lava flow, however, had been reported until Tuesday. [More]

How Boys Become Boys (and Sometimes Girls) [News]

Tue, 06 May 2008 12:00:00 EST

In research that could give doctors a way to reassign sex in cases of unclear gender, scientists report this week that they have figured out why some children with genes that should make them boys are instead born as girls. [More]

A Dump Truck for the 21st Century [News]

Tue, 06 May 2008 11:00:00 EST

Slideshow: View the "super tipper" [More]

Why the Next President Needs a Powerful Science Adviser [Scientific American Magazine]

Tue, 06 May 2008 08:19:00 EST

In the wake of the near panic over the launch of Sputnik in 1957, President Dwight D. Eisenhower appointed James Killian, the president of the Massachusetts Institute of Technology, to become the first special assistant to the president for science and technology. Ever since, the relationship between the nation’s chief executive and the White House’s resident authority on nuclear fission, the workings of DNA and the greenhouse effect, among an array of topics, has had its highs and lows.

To be sure, advice has flowed freely at times. Eisenhower consulted frequently with Killian and other scientists, and in the Kennedy years Jerome Wiesner, another M.I.T. president, helped to coordinate the government’s response to the publication of Rachel Carson’s Silent Spring, a book that spurred a national grassroots environmental movement by pointing out the dangers of pesticides.

[More]

Cell Number Is Future Fat Fight Front [60-Second Science]

Tue, 06 May 2008 00:00:08 EST

Podcast Transcript: Losing weight is no walk in the park. (Although a walk in the park wouldn’t hurt). Seems no matter what diet you try, those stubborn love handles just won’t go away. Part of the problem is that the bulk of your bulk is stored inside fat cells. And the number of fat cells you have is set before you reach adulthood. So if you chunked up as a child, that battalion of fat cells is with you for life. It’s enough to make you want to bury your face in a tray of brownies, I know. But hold off. Because researchers from Stockholm think they’ve found a loophole. [More]

The Monitor: Episode 13 [SciAm Exclusives Video]

Tue, 06 May 2008 00:00:00 EST

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More than 22,000 Dead, 40,000 Missing from Myanmar Cyclone [News]

Mon, 05 May 2008 16:00:00 EST

More than 22,000 people were reported dead and 41,000 more were missing after a cyclone tore through the Southeast Asian country of Myanmar late Friday night and early Saturday morning. Over 10 hours, winds traveling up to 150 miles per hour struck Yangon, Myanmar's largest city, and dumped 20 inches of rain on the harbortown, formerly known as Rangoon. According to published reports, the country's foreign minister fears the final death toll may rise as high as 50,000. That would make the storm -- Tropical Cyclone Nargis -- one of Myanmar's most deadly natural disasters and the second largest in the region after the tsunami of 2004, which took nearly 200,000 lives. [More]

A Bug's Sex Life: A Q&A with Isabella Rossellini [Features]

Mon, 05 May 2008 13:40:00 EST

Isabella Rossellini, well known as a supermodel and movie star, is now making short films for mobile devices that illustrate the sex lives of dragonflies, earthworms and other creatures. But they are not like standard nature shows. In these films, which she researched with the help of Wildlife Conservation Society experts, she not only details unusual aspects of the critters' biology but also dresses up as them and mimics sex with paper cutouts. We asked Rossellini what she hopes to accomplish with the films on invertebrate love, dubbed Green Porno, which premiers May 5 on the Sundance Channel’s Web site. A version of this story will appear in the July issue of Scientific American.

How did you get started making these short films? [More]

Sundance Channel Presents: Green Porno [Video] [Features]

Mon, 05 May 2008 13:35:00 EST

Editor's Note: These videos accompany our feature "A Bug's Sex Life: A Q&A with Isabella Rossellini" an interview with Isabella Rossellini on her new series "Green Porno"

[More]

Hard Drive Recovered from Columbia Shuttle Solves Physics Problem [News]

Mon, 05 May 2008 13:33:00 EST

Researchers have finally published the results of data recovered from a cracked and singed hard drive that fell to Earth in the debris from the Space Shuttle Columbia, which broke up during reentry on February 1, 2003, killing all seven crew members.

The hard drive contained data from the CVX-2 (Critical Viscosity of Xenon) experiment, designed to study the way xenon gas flows in microgravity. The findings, published this April in the journal Physical Review E, confirmed that when stirred vigorously, xenon exhibits a sudden change in viscosity known as shear thinning. The same effect allows whipped cream and ketchup to go from flowing smoothly like liquids to holding their shapes like solids.

[More]

Are There Missing Pieces to the Human Genome Project? [News]

Mon, 05 May 2008 13:00:00 EST

If you ask the scientists at the National Human Genome Research Institute (NHGRI) when the Human Genome Project wrapped up, they'll tell you it was finished in 2003. However, a new study indicates that the composite reference genome cobbled together from parts of the genetic codes of multiple people, is definitely a work in progress. [More]

Dog Walking Irks Birds [Features]

Mon, 05 May 2008 12:45:00 EST

Since dogs were first trained to hunt birds, relations haven't been especially rosy between the two. Dog walkers and bird watchers have a prickly relationship too, often clashing over the use of recreation areas. And now a new study threatens to inflame tempers even more, suggesting that bird sanctuaries be off limits to even those pooches on short leashes.

Currently, dogs roam triumphant in many places, although the Audubon Society lists bird habitats (in Alaska, California, Oregon, Florida, South Carolina and New Jersey) where it considers dog walking to be a threat. Other areas established to safeguard critically endangered birds, such as the Mississippi Sandhill Crane National Wildlife Refuge along the Gulf Coast, currently allow pups in select pockets as long as they are leashed.

[More]

The Lure of Bette Davis Eyes [60-Second Psych]

Mon, 05 May 2008 11:30:08 EST

Podcast Transcript: Out of all the features in a face, we might guess the eyes hold court. And the larger, the better. Think Bette Davis, nocturnal tarsiers, babies… [More]

Protein Shape Data Confirms Life's Genealogy [60-Second Science]

Mon, 05 May 2008 10:15:08 EST

Podcast Transcript: Biologists often attempt to construct a genealogy that shows the relationships of all life on earth. One well-accepted effort compares the nucleic acid sequences that code for ribosomal RNA and a few proteins in many different organisms. The result shows clear groupings. The bacteria cluster together, the eukaryotes--that’s you and frogs and maple trees--all go together. And archae, a distinct kind of single cell, go together. [More]

Regulating Evolution: How Gene Switches Make Life [Scientific American Magazine]

Mon, 05 May 2008 08:15:00 EST

At first glance, the list of animals could suggest any zoo. There’s an elephant, an armadillo, an opossum, a dolphin, a sloth, a hedgehog, big and small bats, a couple of shrews, some fish, a macaque, an orangutan, a chimpanzee and a gorilla--to name a few of the more familiar creatures. But this menagerie is not at all like any zoo that has been constructed before. There are no cages, no concession stands and, in fact, no animals. It is a “virtual” zoo that contains only the DNA sequences of those animals--the hundreds of millions to billions of letters of DNA code that make up the genetic recipe for each species.

The most excited visitors to this new molecular zoo are evolutionary biologists, because within it lies a massive and detailed record of evolution. For many decades, scientists have longed to understand how the great diversity of species has arisen. We have known for half a century that changes in physical traits, from body color to brain size, stem from changes in DNA. Determining precisely what changes to the vast expanse of DNA sequences are responsible for giving animals their unique appearance was out of reach until recently, however.

[More]

Fishing for Oxygen in Warming Oceans [News]

Fri, 02 May 2008 18:00:00 EST

Records stretching back to 1960 prove what climate models had predicted: warmer oceans contain less oxygen. Oceanographer Lothar Stramma of the University of Kiel in Germany and his colleagues report in Science that an analysis of historical records and recent samples show that as the globe has warmed, waters with low oxygen content have expanded in the tropical Atlantic and equatorial Pacific oceans. [More]

News Bytes of the Week--Was the Red Baron Just Lucky? [News]

Fri, 02 May 2008 17:00:00 EST

Was the Red Baron just lucky?Manfred Albrecht Freiherr von Richthofen, better known as the Red Baron, was the most feared German flying ace of World War I. He racked up 80 official air combat victories--the biggest winning streak on either side--before being shot down on April 21, 1918, over northern France. We're inclined to interpret the Baron's record as proof that he was the best of the best. But a study published in the Journal of Mathematical Sociology claims that much of Richthofen's success could be chalked up to plain old luck. German records list 2,894 WWI fighter pilots, who together scored 6,759 victories (planes shot down) and only 810 defeats. Although the win ratio seems suspiciously high, electrical engineers Mikhail Simkin and Vwani Roychowdhury of the University of California, Los Angeles, contend they can still use the numbers to analyze the pilots' defeat rate--their total chances of being shot down after each flight. That rate started off high--25 percent for the first flight--but fell sharply; by the 10th flight it had leveled off below 5 percent, consistent with the weaker pilots getting picked off and the remaining aces having similar skills in the air. At that rate, the researchers conclude that the odds of one in 2,894 pilots racking up an 80-win streak are about 30 percent--not so remarkable after all.

[More]

Do different cells in our nose respond to different smells? [Ask the Experts]

Fri, 02 May 2008 12:00:00 EST

People can smell thousands--perhaps even millions--of different scents. Yet scientists know that in the nose, there are only about 400 different types of odor receptors--proteins that capture scented molecules so that smells can be identified. Thus, there isn’t, obviously, one type of receptor that responds to a rose, while another jumps for jasmine. [More]

A Silver Coating in the Fight Against Microbes [News]

Fri, 02 May 2008 10:50:00 EST

A new technique in paint making could soon make almost any surface germfree. Researchers have made paint that is embedded with silver nanoparticles known for their ability to kill bacteria and other microbes, in the hope that hospitals will coat their walls and countertops to fight infection.

According to the U.S. Centers for Disease Control and Prevention (CDC), more than one million people a year contract bacterial infections in hospitals. Silver itself is an excellent bacteria fighter, and in nanoparticle form it is even more potent at killing microorganisms. So far it has not shown any adverse effects in humans.

[More]

Fishing Lines That Repel Sharks [60-Second Science]

Fri, 02 May 2008 10:20:08 EST

Podcast Transcript: Sharks inspire fear as great predators, but their numbers are declining around the world. One way sharks occasionally meet their doom is by getting tangled up in long-line fishing gear. And they can eat the bait set out for the desired fish, which makes fishing less efficient and more expensive. But scientists at the National Oceanic and Atmospheric Administration recently noticed something unusual. They reported their findings at a workshop on shark-deterrence. [More]

100 Years Ago: Whitest Printing Plant in the World [Scientific American Magazine]

Fri, 02 May 2008 10:11:00 EST

MAY 1958SELF-- “Most of us live behind a wall or smoke-screen which in some degree hides our true thoughts, feelings, beliefs, desires, likes and dislikes. But the question of self-disclosure goes deeper than mere willingness or reluctance. People often cannot disclose themselves, even if they would, because they do not know their real selves--what they really want, feel or believe. Karen Horney has called this phenomenon of being a stranger to oneself ‘self-alienation,’ and she finds it characteristic of neurotics. It may be significant of modern society that so many people have taken to the psychoanalyst’s couch to try to know themselves.”

[More]

Congress Passes Bill Barring Genetic Discrimination [News]

Thu, 01 May 2008 19:00:00 EST

The House today passed a measure by a whopping 414-to-1 margin that would prohibit health insurers from canceling or denying coverage or hiking premiums based on a genetic predisposition to a specific disease. The legislation, the Genetic Information Nondiscrimination Act (GINA), also bars employers from using genetic information to hire, fire, promote or make any other employment-related decisions. [More]

Charcoal in Burned Forests No Way to Store Carbon [News]

Thu, 01 May 2008 19:00:00 EST

The boreal forests in the north of Canada, Russia and other countries that ring the Arctic burn every summer after lightning strikes their towering trees, releasing tons of carbon dioxide into the air as they turn to ash and charcoal in the flames. Some scientists have argued, however, that this climate-changing natural disaster might not be all bad from a global warming perspective: Charcoal is a stable way to store carbon in the ground, where the carbon-rich charcoal can safely stay for hundreds if not thousands of years. Or at least that's the theory of so-called biochar. A new study published today in Science shows that such charcoal may not keep as much carbon in the soil as previously believed. [More]

James Watson, six months later, still apologizing [Sciam Observations Blog]

Thu, 01 May 2008 17:50:08 EST

You'd think James Watson would be pretty good at apologizing by now. [More]

Missing Link of Electronics Discovered: "Memristor" [News]

Thu, 01 May 2008 12:00:00 EST

After nearly 40 years, researchers have discovered a new type of building block for electronic circuits. And there's at least a chance it will spare you from recharging your phone every other day. Scientists at Hewlett-Packard Laboratories in Palo Alto, Calif., report in Nature that a new nanometer-scale electric switch "remembers" whether it is on or off after its power is turned off. (A nanometer is one billionth of a meter.)

Researchers believe that the memristor, or memory resistor, might become a useful tool for constructing nonvolatile computer memory, which is not lost when the power goes off, or for keeping the computer industry on pace to satisfy Moore's law, the exponential growth in processing power every 18 months.

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Buried Prejudice: The Bigot in Your Brain [Scientific American Mind]

Thu, 01 May 2008 09:55:00 EST

"There is nothing more painful to me at this stage in my life,” Jesse Jackson once told an audience, “than to walk down the street and hear footsteps and start thinking about robbery--then look around and see somebody white and feel relieved.”

Jackson’s remark illustrates a basic fact of our social existence, one that even a committed black civil-rights leader cannot escape: ideas that we may not endorse--for example, that a black stranger might harm us but a white one probably would not--can nonetheless lodge themselves in our minds and, without our permission or awareness, color our perceptions, expectations and judgments.

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Nutcracker Man Preferred Soft Fruits [60-Second Science]

Thu, 01 May 2008 00:00:08 EST

Podcast Transcript: Some people lie through their teeth. Some lie about their teeth. Our early human cousins seem to have lied with their teeth. Or they at least misled scientists into first thinking that their diet was something other than it was. See, one of our East African relatives had chompers that looked so powerful, scientists nicknamed him “Nutcracker man.” With teeth and jaws so big and strong, everyone assumed that Paranthropus boisei was partial to nuts and seeds and other crunchy fare. [More]

Puzzling Adventures: How to Make Buses More Attractive Than Cars? [Puzzling Adventures]

Thu, 01 May 2008 00:00:00 EST

Like many cities of the North American Sunbelt, Las Gridas is a big grid of two-way roads (three lanes for each direction), some going east-west and some north-south. Most people get around by driving their cars. But gridlock and energy costs have finally driven the normally car-loving culture to reconsider its disdain for buses. [More]