Scientific American Online

Today's supercomputers run hot, thanks to power-hungry microprocessors that enable sophisticated scientific research and complex financial transactions to be performed in the blink of an eye. As these microprocessors have become smaller and more powerful over time , they are generating even more heat, a problem that data centers generally address expensively with air conditioning and chilled-liquid cooling systems. [More]

Fire and ice have created a doubly dangerous and disruptive volcanic disaster in Iceland that is being felt around the world as locals are evacuated and thousands of flights to and from Northern and Western Europe have been grounded. [More]

The human brain is considered to be pretty quick, but it lacks many of qualities of a super-efficient computer. For instance, we have trouble switching between tasks and cannot seem to actually do more than one thing at a time. So despite the increasing options --and demands--to multitask, our brains seem to have trouble keeping tabs on many activities at once . [More]

A team of researchers has devised perhaps the world's most intricate coin toss, a device utilizing vacuum chambers, magnetic fields, lasers and microwave pulses to produce a random string of 0s and 1s--each representing heads or tails, essentially. The complexity is necessary to move the generation of random numbers beyond the hard-to-predict but fundamentally deterministic world of classical physics and into the realm of quantum mechanics, where uncertainty takes hold. [More]

Eat something that's bad for you and you get sick, effectively teaching you to never eat that thing again. But if you eat something that kills you, there's not much room left for learning, is there?

That's the problem in Australia, where the endangered northern quoll ( Dasyurus hallucatus ), a small, cat-sized marsupial , has been driven to near-extinction by eating poisonous cane toads ( Bufo marinus ). Now some scientists are trying to help quolls, and maybe other species, by teaching them that cane toads are not food and should be avoided.

Last week, scientists announced the discovery of a remarkably well-preserved skeleton of what might be a new species of an ancient hominid that lived almost 2 million years ago. [See Kate Wong, http://bit.ly/dehy9Q ]

The bones were found in 2008. This February, they were analyzed by one of the highest-tech tools available, the synchrotron at the European Synchrotron Radiation Facility in Grenoble, France. The device uses beams of x-rays a trillion times brighter than medical x-rays, and produces images at the atomic level.

President Obama promised to eliminate 34 tons of plutonium from the U.S. nuclear weapons program as part of this week's nuclear security summit. But how does one actually get rid of bomb-making material that has a half-life of more than 20,000 years? [More]

HATING “LOVE” After reading Robert Epstein’s article “ How Science Can Help You Fall in Love ,” I had to go back to the cover and verify that the word “scientific” was indeed part of the title of your magazine. The “Love-Building Exercises” he recommends are more appropriate to a magazine of fantasy and science fiction: [More]

At age 22, Eliezer Sternberg has just published his second book on neuroscience and philosophy: “My Brain Made Me Do It,” now out from Prometheus Books. In it, he argues that our growing understanding of how the brain works does not mean the end of moral responsibility. Rather, he sees free will as a special property that emerges from more basic brain functions. A student at Tufts Medical School, he took time out from his first-year exams to talk with Mind Matters co-editor Carey Goldberg. [More]

In late 2008 two teams made waves with the simultaneous announcement that they had managed to directly photograph planets in orbit around distant stars, also known as exoplanets. Although hundreds of exoplanets had already been found orbiting sun-like stars throughout the Milky Way, they had been discovered by indirect means--astronomers had inferred the presence of a planet by observing the dimming effects or gravitational wobble an orbiting companion induces on its parent star. In a few other cases a candidate planet had been observed near a star but had not been proved to follow a planet-like orbit. [More]

Resistance to glyphosate, a herbicide more popularly known as Roundup, has been rising among weeds across the American Southeast that are growing among genetically engineered crops, according to a report released today by the National Research Council .

"Weed resistance is so bad in Georgia that GE cotton is no longer being used as much," said LaReesa Wolfenbarger , a co-author of the report and associate professor of biology at the University of Nebraska. The committee presented its work at the National Academy of Sciences today.

By Sharon Weinberger

By highlighting the limits of traditional military technology, the drawn-out conflicts in Iraq and Afghanistan have spurred the U.S. [More]

By Peter Griffiths

LONDON (Reuters) - An inquiry cleared British climate researchers of wrongdoing on Wednesday after their emails were hacked, leaked and held up by skeptics as evidence they had exaggerated the case for man-made global warming.

* Thousands injured after series of quakes, aftershocks

* Schools cave in, some students trapped

One main goal in the renewable energy field is to find an efficient, inexpensive way to split water into hydrogen and oxygen. The hydrogen could then be used as a fuel source for vehicles or fuel cells. Typically, an electric current breaks the water down. Now, there’s a new water-splitter: a virus. M.I.T.’s Angela Belcher took her cue from plants, where special pigments capture solar energy in photosynthesis, involving the splitting of water. [More]

Six days from now, every one of the billions of phytoplankton alive today will be dead--eaten by zooplankton or having drifted to the bottom of the sea . In fact, some of these microscopic plants, which collectively perform as much as photosynthesis as all of Earth's land-based plants, live for just two days. [More]

There is ample evidence that men and women think, express themselves and even experience emotions differently (for more details, read on through this issue). But in the area of sensory perception, psychologists are hard-pressed to identify major discrepancies. By and large, the way the two genders experience the sounds, sights and smells of life is quite similar. The most striking exception may be found, at least for some, in the perception of colors.

Seeing in color is a complex process, as you may remember from your school days. It starts with the delicate lining of the eyes, a structure called the retina. Retinal tissue contains light-sensitive cells that absorb wavelengths in the visible spectrum and convert them into electrical signals. The brain interprets this information as the riot of colors we consciously experience. The retinal cells called cones come in three varieties. The S-type cone is maximally sensitive to light in the short-wavelength (blue) part of the visible spectrum, the M-type cone responds best to medium wavelengths, and the L-type to long, reddish wavelengths. People with normal color vision are known as trichromats because they possess these three kinds of photosensitive cone cells.