Новости науки и техники в "Scientific American"

BOOKSTORE: HOW TO BUILD A TIME MACHINE by Paul Davies

Is time travel possible? Yes, says Davies, who recently retired (in his early 50s) as professor of mathematical physics at the University of Adelaide in Australia to concentrate on his writing. But "a moment's thought uncovers some tricky questions." Whereupon he discusses lucidly and engagingly both the concepts of physics that establish the possibility of time travel and the tricky questions. You could reach the future "by simply moving very fast." For visiting the past, the most popular proposal is a wormhole, "a sculpture in the structure of space that provides a shortcut between two widely separated spaces." There may be "cosmic taboos," though, that make time travel forever elusive.

CLIMATE WARMING CAUSES COLLAPSE OF ANTARCTIC ICE SHELF

The northern section of the Larsen B ice shelf - a slab of floating ice on the eastern side of the Antarctic Peninsula - has collapsed and separated from the continent, researchers report. The incident is the largest single event in a 30-year series of ice shelf retreats in the area and appears to be the result of rapid warming there.

A WAY WITH WORDS

The way you speak says a lot about you. Your dialect or accent might indicate where you grew up, for instance, while your vocabulary may suggest the type of education you've had. But can the language you use indicate the way you think, or help shape those thoughts? In the 1930s, American linguist Benjamin Lee Whorf argued persuasively that language did indeed affect thought, but his views fell out of favor. Now a group of cognitive psychologists has revived the search for the effects of language on the mind, with some provocative results.

CHANDRA ILLUMINATES DIFFERENCE BETWEEN DISTANT DOUBLE QUASARS

Since its discovery more than two decades ago, the double quasar system Q2345+007A,B has confounded astronomers. Often such apparent quasar pairs are in fact optical illusions caused by so-called gravitational bending. New results from the Chandra X-ray Observatory, however, suggest that the twins are in fact distinct objects formed by merging galaxies.

ETHIOPIAN FOSSIL DISCOVERY PRUNES HUMAN FAMILY TREE

Scholars of human evolution have long debated just how many branches and twigs make up the human family tree. Some place the known human fossils into numerous genera and species, creating a bushy tree. Others tend to see more similarities between fossils and opt for trees with fewer offshoots. Now recently recovered fossils from Ethiopia indicate that for at least one part of the human pedigree, less is more.

ASK THE EXPERTS: HOW LONG CAN HUMANS STAY AWAKE?

J. Christian Gillin, a professor of psychiatry at the University of
California, San Diego, explains.