Новости науки и техники в "Scientific American"
17 июня 2003 г. |
SKULLS OF OLDEST HOMO SAPIENS RECOVEREDScientists have unearthed in Ethiopia three 160,000-year-old skulls that they say are the oldest near-modern humans on record. Telltale marks on the bones suggest that the hominids engaged in mortuary rituals.ASTRONOMERS COMPLETE STAR CENSUS IN CENTAURUSA Astronomers have detected more than 1,000 stars with varying brightness in the nearest giant galaxy. These so-called Mira-variable stars are quite common in our own Milky Way and other nearby galaxies, but this is the first time they have been identified in a distant giant elliptical galaxy.BOOKSTORE: IMAGINING NUMBERS (PARTICULARLY THE SQUARE ROOT OF MINUS FIFTEEN) by Barry MazurMazur, a mathematician and university professor at Harvard University, writes "for people who have no training in mathematics and who may not have actively thought about mathematics since high school, or even during it, but who may wish to experience an act of mathematical imagining and to consider how such an experience compares with the imaginative work involved in reading and understanding a phrase in a poem." It is a stimulating and challenging journey, one likely to lead the reader to share Mazur's view: "The great glory of mathematics is its durative nature; that it is one of humankind's longest conversations; that it never finishes by answering some questions and taking a bow. Rather, mathematics views its most cherished answers only as springboards to deeper questions."PET PRAIRIE DOGS SUSPECTED IN U.S. MONKEYPOX OUTBREAKCases of monkeypox have been identified for the first time in North America, the Centers for Disease Control and Prevention (CDC) reports. The disease, which is similar to smallpox but less infectious and less deadly, had previously been found primarily in West and Central Africa. So far, the CDC is investigating 33 potential cases from three states - Wisconsin, Illinois and Indiana - and as of last Monday afternoon, four cases had been confirmed through laboratory testing.THE GALACTIC ODD COUPLEThe two most powerful phenomena in galaxies are active galactic nuclei (AGNs) and starbursts. The former are intense, concentrated sources of light - probably matter falling into a supermassive black hole. Starbursts are galactic fireworks shows during which stars form at a frenetic pace. Astronomers used to think that AGNs and starbursts, which are often separated by vast distances, had nothing to do with each other. But they have found that the two phenomena tend to occur hand in hand. Does an AGN cause the starburst? Or vice versa? Or are they both caused by some underlying process? The answer will be crucial to understanding the evolution of galaxies.ASK THE EXPERTS: ARE HUMANS THE ONLY PRIMATES THAT CRY?Kim A. Bard of the University of Portsmouth explains.