Новости науки и техники в "Scientific American"
7 мая 2002 г. |
THE DAWN OF AUTONOMIC COMPUTINGComputer hardware increases in speed and capacity by factors of thousands each decade; computer software piles on new features and fancier interfaces nearly as fast. So why do computers still waste our time and drive us crazy? Programs crash, people make mistakes, networks grow and change. That's life, and computer scientists are finally building systems that can deal with it.STUDY SHOWS FERTILITY DECLINE BEGINS IN LATE 20SA woman's fertility begins to decline in her late 20s, but her overall chances of becoming pregnant do not start to slide so soon, a new study concludes. Researchers have determined that female fertility starts to fall off gradually around age 27 before dropping more dramatically after age 35. The findings suggest that older would-be parents may have to wait longer before becoming pregnant.RESEARCHERS GUIDE RATS BY REMOTE CONTROLLike players of a life-size video game, scientists have succeeded in controlling the movements of rats from up to 500 meters away. The findings could lead to the development of robo-rodents capable of carrying out dangerous surveillance missions.GAMMA-RAY BURSTS MAY ILLUMINATE HIDDEN GALAXIESThe most powerful explosions in the universe since the big bang could help astronomers find billions of as-yet-undetected stars. A new report suggests that gamma-ray bursts - which release as much energy in a few seconds as the sun does in its entire lifetime - could illuminate hard-to-see, dust-enshrouded galaxies where much of the star formation in the cosmos has taken place.FOSSIL TRACKWAY REVEALS EARLIEST TERRESTRIAL FOOTSTEPSFor millions of years the earth's earliest creatures were obliged to remain in the marine realm. Eventually, however, some animals evolved features that allowed them to establish a toehold on land. Evidence of these ancient trailblazers is vanishingly rare, but a new discovery indicates that they took their first steps ashore far earlier than previously thought. Researchers have found footprints preserved in sandstone that dates to about 530 million years ago - pushing the date of landfall back some 40 million years.BOOKSTORE: CRADLE TO CRADLE: REMAKING THE WAY WE MAKE THINGS by William McDonough and Michael BraungartMcDonough and Braungart (an architect and a chemist) are partners in a firm that creates ecologically intelligent designs for corporations. They argue for a shift from the cradle-to-grave model of manufacturing, in which most of the materials that go into making products end up as waste. They champion a cradle-to-cradle model, in which the materials are "circulated infinitely in industrial cycles ... without loss of quality or damage to our environment or ourselves."ASK THE EXPERTS: DO HIPPOPOTAM USES ACTUALLY HAVE PINK SWEAT?
Mark Ritchie, professor of biology at Syracuse University, answers.