Discover, December 1, 1994

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In 2001, NASA plans to launch a spacecraft that will fly within less than 2 million miles of the sun–and do so without melting.

What we know of the sun we have learned from a safe distance. The Ulysses probe that flew under the south solar pole last June, for instance, did so at a distance of more than 200 million miles. The closest we’ve come to the inferno was 26 million miles, with a 1974 satellite named Helios. As a result there are a lot of things we don’t understand about the sun–why small flares on its surface can produce huge magnetic storms on Earth, for example, or why big flares sometimes barely cause a stir. 

Continue reading “Into the Fire” →

Discover, December 1, 1994

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Carbon dioxide in the atmosphere warms Earth. But just how much warming you get depends on where you put your continents.

If adding carbon dioxide to the atmosphere creates a greenhouse effect that warms Earth, it must have happened in the past. That’s why paleoclimatology, once a small and esoteric field, is such a growth industry these days, with legions of geologists trying to glean past temperatures and CO2 levels from rocks, and legions of climate modelers trying to tell us what it all means–not only for the past but also for the future of Earth’s climate.

Continue reading “Location, Location, Location” →

Discover, October 1, 1994

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Old oceans never die: they are preserved, in scattered fossil form, in the rock of Earth’s mantle, 250 miles down.

Jules Verne had an impressive track record of predicting technological progress, having foretold in his books the invention of rocket flight, the submarine, and television. At first glance he would seem to have had less luck with geology; in Journey to the Center of the Earth Professor Otto Lidenbrock and his nephew Axel travel underground and discover that our planet is hollow. But the Lidenbrocks also sail across a vast underground ocean, and geologists now think Verne was onto something there.

Continue reading “The Ocean Within” →

Discover, September 30, 1994

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Nobody, says University of Arizona ecologist Michael Rosenzweig, is going to come up blind with a program to save biodiversity without understanding why it’s here and how it is maintained. And one of the problems that is stumping Rosenzweig and other biodiversity researchers these days is a strange pattern that keeps popping up wherever they look, from the deep seafloor to the Negev Desert. The pattern is this: When organisms get more of what they need, more nutrients, sunlight, and water, their diversity rises–but only up to a point. After that point, more resources mean more productivity–the rate at which plants grow, making food for animals–but less diversity. It makes absolutely no sense, says Rosenzweig. It’s loony.

Continue reading “More Productive, Less Diverse” →

Discover, September 1, 1994

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The idea of a large, docile animal that would pull your plow and make a good stew occurred to more than one person 8,000 years ago.

Civilization rode into the Old World on the backs of cows. Not only were they a richer source of protein than the pigs, goats, and sheep that had been domesticated earlier, they were also the first draft animals. With cattle pulling plows, farmers were suddenly able to cultivate large areas of previously untillable soil. It was something like the invention of the combustion engine, says Caroline Grigson, a zooarcheologist at the Royal College of Surgeons in London. In fact, the domestication of cattle was so important that it apparently happened more than once.

Continue reading “Cows Were in the Air” →