Discover, April 1, 1992

Link

Along the southern border of the Sahara, in the luckless region known as the Sahel, a drought has been going on for 20 years now. In the 1970s hundreds of thousands of people succumbed to the effects of crop failures and cattle die-offs, and today the millions of farmers and nomads who inhabit the Sahel are still living on the edge. One potent symbol of their plight can be seen from space: Lake Chad, once as big as Lake Erie, is now a third the size. But in that desolate image Solomon Isiorho sees a reason for hope. Some of that vanished water, he says, may still be available for use.

Continue reading “The New Diviner” →

Discover, March 31, 1992

Link

Sitting in a noisy Manhattan restaurant, Joseph Weintraub cuts his steak with obvious pleasure. “This is much better than the one I had last night with the Times of London,” he shouts over the ambient chitchat.

Weintraub doesn’t have much free time these days, what with being wined, dined, and interviewed by newspapers, magazines, and film crews. Until recently, he led a low-profile life, working as a computer consultant and running a small software company in Woodside, Queens. That’s all changed, however, now that he has won the first annual Loebner Prizer, a context designed to see if computers can think.

Continue reading “Flake of Silicon” →

Discover, March 1, 1992

Link

When Burney Le Boeuf started studying elephant seals in 1968, his operation was pretty low tech. Le Boeuf was surveying 4,000-pound bulls at a rookery on Año Nuevo Island off the coast of California, and he had to find a way to tag them so that he would know which bull was which. First he tried a dye-filled fire extinguisher, which he blasted at the sleeping bulls’ flanks. But that woke them up. Then he threw plastic sandwich bags filled with paint at them–too messy. Then he tried a paint roller on a pole, which afforded a bit more control over the shape and placement of the marks.

Continue reading “Portrait in Blubber” →

Discover, March 1, 1992

Link

For ten years University of Hawaii physicist John Learned has been leading a team of researchers who are designing a telescope to be stationed at the bottom of the ocean. That in itself is enough to raise eyebrows, but there’s an even stranger wrinkle: new research shows that the device may someday be able to map not only the outer reaches of the firmament but also the inner depths of Earth’s core.

Continue reading “Watery Eyes” →

Discover, January 31, 1992

Link

Over the past decade geologists have been marshaling scattered evidence that the dinosaurs were done in by an asteroid hitting Earth some 65 million years ago. But in 1991 hey really got down to specifics. The fatal asteroid, they said, hit not far off the coast of the Yucatán peninsula in Mexico–in June.

The impact theory got its start 11 years ago when a team led by Luis and Walter Alvarez examined the thin layer of clay that appears at the geologic dividing line marking the transition from the Cretaceous Period to the Tertiary Period–a point known as the K-T boundary. Inside the clay were high levels of the metal iridium, uncommon in Earth’s crust but plentiful in extraterrestrial objects.

Continue reading “The Smoking Crater” →