Новости науки и техники в "Scientific American"

SECOND LAW OF THERMODYNAMICS VIOLATED

It seems that something odd happens to the second law of thermodynamics when systems get sufficiently small. The law states that the entropy, or disorder, of the universe increases over time and it holds true for large-scale systems. For instance, whereas a hot beverage will spontaneously dissipate heat to the surrounding air (an increase in disorder), the air cannot heat the liquid without added energy. But scientists predicted nearly a decade ago that small assemblages of molecules inside larger systems may not always abide by the principle. Now Australian researchers report that even larger systems of thousands of molecules can also undergo fleeting energy increases that seem to violate the venerable law.

FIREFLY GLOW HELPS SCIENTISTS TO TRACK THE SPREAD OF PROSTATE CANCER

Prostate cancer is the second leading cause of cancer deaths in American men. Current screening options and therapies for the disease can be inadequate for many patients, prompting researchers to investigate gene therapy as a potential alternative. To kill tumor cells using gene-based techniques, scientists must be able to specifically target only the prostate's diseased cells, as well as any metastases that may have formed in the organ and traveled to other parts of the body. They also need to assess how well the therapy is working. To that end, investigators have succeeded in detecting the spread of prostate cancer in mice using a firefly protein to light up culprit tumors. The findings could provide the basis for improved treatments for humans suffering from the disease.

BOOKSTORE: THE FATE OF THE MAMMOTH: FOSSILS, MYTH, AND HISTORY by Claudine Cohen

The mammoth, Cohen writes, "shares traits both of the elephant and the teddy bear." She tells the story of this extinct creature as a means of telling the story of paleontology. Both stories read well. Cohen, who teaches the history of science at the School of Higher Studies in Social Sciences in Paris, examines the possible reasons for the extinction of the mammoths and considers the possibilities for reviving the species through cloning. "By giving life to extinct species," she writes, "paleontology would surpass itself and move from being a science of death to truly being a science of life."

NEW BUBBLE REACTION FINDINGS MAKE FUSION CLAIMS UNLIKELY

Sonoluminescence, the process in which light is created when sound waves move through a liquid and cause bubbles to expand and collapse, was at the center of a contentious scientific debate earlier this year. A team of researchers reported that they had exploited the phenomenon to achieve nuclear fusion using a tabletop apparatus, an assertion that quickly met with skepticism. New research casts further doubt on those claims. Scientists have directly measured the reaction rates inside a single bubble as it sonoluminesces and the findings suggest so-called bubble fusion is "most unlikely."

THE SMALLEST EVER LASER-LIKE LIGHT BEAM

As computer technologies continue to shrink to nanoscale dimensions, scientists are finding it increasingly difficult to view and measure their tiny creations. Just billionths of a meter in length, modern machine components are actually becoming smaller than the wavelengths of light used to view them. Researchers have attempted to create laser-type light beams of extremely short wavelengths for viewing these minuscule objects, but the results have typically been weak and the apparatus too cumbersome for practical applications. Now scientists appear to have found a way to create this so-called extreme-ultraviolet light, using equipment that can fit on a dining room table.

FOSSIL HINTS AT HOW PTEROSAUR HUNTED

The remains of a previously undescribed species of pterosaur are yielding fresh clues to how these distinctive animals hunted for food. The fossil represents a beast that may have captured its prey by skimming the surfaces of lakes and oceans. Given the huge, bony crest that adorned its head, the flying reptile would have been hard to miss.

ASK THE EXPERTS: WHAT IS THE DIFFERENCE BETWEEN NATURAL AND ARTIFICIAL FLAVORS?

Gary Reineccius, a professor of food chemistry at the University of Minnesota, explains.