Sigma Chi Chimpy

FORGET THE LADIES FOR CHIMPS, HUNTING IS ABOUT FRATERNITY BY MEREDITH F. SMALL The patrol of chimpanzees leaves early in the afternoon, silently moving through the forest in single file. After several hours, the hunters hear a troop of monkeys jumping nervously about the canopy. The chimps stop, grab one another and grin in anticipation of the feast to come. Then all hell breaks loose. The chimps shout a rallying cry and climb purposefully into the trees. The monkeys scream in alarm and mob the...

Tan or Burn

While protecting your body, skin must protect itself from the sun's ultraviolet radiation, which can cause premature aging and cancers. Sunscreens can help. Sunburn occurs when strong UV rays harm cells in the skin's outermost layer, the epidermis. Blood vessels in deeper layers dilate, turning the skin red a sunburn. Regular exposure causes the epidermis to produce more melanin pigment in an attempt to absorb UV rays. If enough melanin accumulates, the skin darkens a tan. Dark-skinned people...

Air Traffic Out of Control

NASA recently flight-tested an advanced jet engine able to reach seven times the speed of sound. Talk was heard of hypersonic airliners zooming from New York City to Los Angeles in 45 minutes. If such a flight were made today, however, chances are good that the plane would be forced to circle over LAX for a few hours before it could be cleared to land. As the numbers of airline passengers and flights B increase, the nation's air traffic stretched beyond its limits. With one in four flights...

Crush on Nitrogen

Nitrogen prefers to turn into a semiconductor. Russell J. Hemley and his colleagues at the Carnegie Institution of Washington squeezed nitrogen gas between diamond faces, generating pressures up to 2.4 million atmospheres 240 giga-pascals . The gas transformed into a semiconducting solid what is more, the nitrogen stayed that way when the pressure returned to normal. This dense form of nitrogen might serve as a novel semiconductor as well as demonstrate what's...