Новости науки и техники в "Scientific American"
11 июня 2002 г. |
SECRETS OF THE STRADIVARIUSWith a tone that is at once brilliant and sonorous, the violins created by Antonio Stradivari in the 17th and 18th centuries stand alone. For years, instrument makers and scientists have studied the extraordinary violins, hoping to uncover their secrets. Now one investigator believes that reproduction of that legendary sound is within reach. The key, expounds Joseph Nagyvary of Texas A&M University in an interview with SCIENTIFIC AMERICAN, lies in the chemistry.SCIENTISTS SUCCEED IN TRANSPLANTING CLONED COW TISSUEBecause the human body rejects most introduced tissue, locating an organ that will be accepted by a patient's immune system remains a significant challenge for transplantation medicine. Creating cells that are genetically identical to those of the patient offers one solution to this problem. Now researchers have illustrated that, though it is not yet feasible in humans, this approach can work in cows. Using so-called therapeutic cloning, scientists found that cloned cells can function in the body of a bovine transplant recipient without being rejected.BOOKSTORE: COSMOLOGICAL PHYSICS by John A. PeacockThis textbook provides advanced undergraduate and graduate students with a comprehensive introduction to modern cosmology. Throughout this authoritative volume, emphasis is given to the simplest, most intuitive explanation for key equations used by professional researchers in both theoretical and observational cosmology, which are derived and explained from first principles. The book is well illustrated with helpful figures and includes outline solutions to more than 90 problems. All necessary astronomical jargon is clearly explained, ensuring the book is self-contained.RISING TEMPERATURES TIED TO FLOWERS' EARLIER BLOOMThe results of a new study suggest that rising temperatures are leaving a mark on the world. Researchers report that the first flowering of plants in Britain has changed by as much as 55 days over the past few decades in response to warmer weather. The results, the scientists say, are the "strongest biological signal yet of climatic change."HUMAN HOSTS HELP CHOLERA BACTERIUM BECOME MORE INFECTIOUSThe cholera bacterium flourishes in countries suffering from poor sanitation and urban crowding. Now a new study suggests that the presence of human beings can make the disease more communicable. The findings indicate that passage through the human digestive system produces a version of the bacteria up to 700 times more infectious than the same bacteria originating in water or soil.SCIENTISTS ADD NEW DIMENSION TO SUPERNOVAE SIMULATIONSBriefly exceeding the power of 100 billion stars, a supernova explosion ironically signifies the death of a massive celestial sun. Since 1966, researchers have developed increasingly more realistic computer simulations of these dazzling events. First one-dimensional, then two-dimensional, the models have gradually revealed key details behind supernova activity. Now scientists have created the first three-dimensional models that depict star collapse and the subsequent tremendous explosion.ASK THE EXPERTS: WHY DO CLOUDS FLOAT WHEN THEY HAVE TONS OF WATER IN THEM?Douglas Wesley, a senior meteorologist in the Cooperative Program for Operational Meteorology, Education and Training (COMET) at the University Corporation for Atmospheric Research, explains.