Новости науки и техники в "Scientific American"

AIR POLLUTION INDUCES DNA MUTATIONS IN MICE

The respiratory effects of air pollution are well documented. Now researchers report that industrial pollution could cause genetic defects, too. Mice subjected to ambient air in close proximity to a steel mill had twice as many genetic mutations as their rural counterparts did.

JUPITER MOON JUST A 'PILE OF RUBBLE'

The Galileo spacecraft, which was launched 13 years ago, is scheduled to crash into Jupiter in September 2003. On its final flyby of the planet last month, the probe came within 160 kilometers of Amalthea, one of Jupiter's many moons. Findings from that encounter indicate that the strangely shaped inner moon is full of empty space.

BOOKSTORE: FLASH!: THE HUNT FOR THE BIGGEST EXPLOSIONS IN THE UNIVERSE by Govert Schilling

About three times a day our sky flashes with a powerful pulse of gamma ray bursts (GRB), invisible to human eyes but not to astronomers' instruments. The sources of this intense radiation are likely to be emitting, within the span of seconds or minutes, more energy than the sun will in its entire 10 billion years of life. Where these bursts originate, and how they come to have such incredible energies, is a mystery scientists have been trying to solve for three decades. The phenomenon has resisted study - the flashes come from random directions in space and vanish without trace - until very recently. In what could be called a cinematic conflation of Flash Gordon and The Hunt for Red October, Govert Schilling's Flash!: The Hunt for the Biggest Explosions in the Universe describes the exciting and ever-changing field of GRB research. Based on interviews with leading scientists, Flash! provides an insider's account of the scientific challenges involved in unraveling the enigmatic nature of GRBs.

HOW TO FLOAT LIKE A BUTTERFLY

The intricacies of insect flight are astounding. But the animals' small size and swift movements make detailed studies of their aerodynamic acrobatics difficult. New research reveals that the insects rely on a variety of techniques, often employed in successive strokes, over the course of a flight.

BORN TO THE PURPLE: THE STORY OF PORPHYRIA

Porphyrins are light-activated chemicals that can be used to combat ills including tumors and diseases of the eye. But they have a dark side: when the wrong forms of them build up in the body, they cause a disease called porphyria. There are at least eight types of porphyria, which vary substantially in their symptoms and severity. Historical victims of the worst, most disfiguring forms may have inspired tales of werewolves and vampires. Even today, managing the disease can be challenging.

ASTEROIDS COULD HAVE CAUSED FLASH FLOODS ON YOUNG MARS

Space missions to Mars in the 1970s first brought back the surprising news that the Red Planet had once been awash in water. Ever since then, scientists have been working to determine the source of the flowing water that left telltale tracks on Mars's surface. New work hints that collisions with comets and asteroids during the planet's early years may have played a role.

ASK THE EXPERTS: HOW DOES ONE ARRIVE AT THE EXACT NUMBER OF CYCLES OF RADIATION A CESIUM-133 ATOM MAKES IN ORDER TO DEFINE ONE SECOND?

Donald B. Sullivan, a physicist and chief of the time and frequency division of the National Institute of Standards and Technology, explains.