Новости науки и техники в "Scientific American"

THE ARMY OF THE FUTURE

The U.S. Army wants to get to and maneuver within trouble spots faster, and over the next six years it will spend $91 billion figuring out how to do that. The goal sounds simple: be able to send a brigade anywhere in the world within 96 hours, a division within 120 hours and five divisions within 30 days. Achieving that goal, however, means transforming the army from a ponderous force built around the use of tanks and other heavy vehicles to one that is comprised of lighter, less heavily armored vehicles that can sprint across the battlefield at speeds of 60 mph and that can deliver the same dose of lethality as their bigger predecessors.

NICOTINE, TOO, MAY PROMOTE CANCER

As a new year begins, cigarettes are no doubt the focus of countless resolutions. But the highly addictive nature of nicotine makes butting out hard to do. New research may provide smokers with further impetus to kick the habit. Although tar has long been considered the carcinogenic agent in cigarettes, these findings further suggest that nicotine and compounds derived from it may also promote the development and progression of cancer.

MILKY WAY ENCIRCLED BY STARS

The Milky Way contains billions of stars, but it is a relatively small band of celestial bodies just outside our galaxy that has caught the attention of astronomers. It seems that a previously unseen belt of stars, rotating at 100 kilometers a second, girds the Milky Way.

SNOW ALGAE ABSORB GREENHOUSE GAS

The unicellular alga Chlamydomonas nivalis leaves its mark on snowfields with a telltale pinkish hue. The red algae typically live at altitudes higher than 2,500 meters and temperatures below freezing. Despite such harsh conditions and correspondingly high radiation levels, C. nivalis can remove carbon dioxide from its surroundings through photosynthesis.

BOOKSTORE: A SHORTCUT THROUGH TIME: THE PATH TO THE QUANTUM COMPUTER by George Johnson

In the 1960s Gordon Moore made the empirical observation that the density of components on a chip was doubling roughly every 18 months. Over the past 40 years, Moore's law has continued to hold. These doublings in chip density explain why today's personal computers are as powerful as those that only governments and large corporations possessed just a couple decades ago. But in 10 to 20 years each transistor will have shrunk to atomic size, and Moore's law, which is based on current silicon technology, is expected to end. This prospect drives the search for entirely new technologies, and one major candidate is a quantum computer - that is, a computer based on the principles of quantum mechanics. There is another motive for studying quantum computers. The functioning of such a device, which lies at the intersection of quantum mechanics, computer science and mathematics, has aroused great intellectual curiosity.

EXPLAINING THE MOON'S ANCIENT MAGNETISM

These days, a compass on the moon doesn't do much because there is no magnetic field to entice its hands to move. But it may not have always been so. Analysis of rocks recovered during the Apollo missions has uncovered telltale signs of ancient lunar magnetism. A new computer model may help explain the magnetism mystery.

ASK THE EXPERT: WHY DO MEN HAVE NIPPLES?

Andrew M. Simons, a professor of biology at Carleton University in Ottawa, Ontario, explains.