Discover, July 1, 1994
Lasers have become ubiquitous: they read the prices of our groceries, play our compact discs, and even clean our clogged arteries. Now, thanks to a group of French physicists, the world has its first saser- -a device that amplifies sound the way lasers amplify light. The saser isn’t of much use yet, but one day the researchers hope to turn it into the world’s most sensitive listening device.
Discover, June 1, 1994
Most fireflies flash at random, each to its own drummer. In Tennessee there are fireflies that do it differently: they synchronize.
The fireflies that will emerge this June around the United States will generally flash in a random-looking fashion, each one sending its own signal–except for the ones that live in the clearing next to the Faust family cabin in the Great Smoky Mountains of Tennessee. Those fireflies will send out five to eight flashes in unison, stop for a quarter of a minute, and then do it again.
Discover, May 1, 1994
On the one hand, greenhouse gases aren’t piling up in the atmosphere as fast as they used to. On the other hand, it can’t last.
Something surprising has happened: the accumulation of greenhouse gases in Earth’s atmosphere, the gases that trap heat and warm the planet, has slowed down. Carbon dioxide, the most important greenhouse gas, has in recent years been increasing at around half its previous rate. Methane, less abundant than carbon dioxide but 20 times as effective (molecule for molecule) at absorbing heat, may be on the verge of leveling off. The same is true of chlorofluorocarbons, which are better known as ozone destroyers but are the most efficient heat absorbers of all.
Discover, March 1, 1994
In Rwanda’s Nyungwe Forest, researchers are finding it hard to sell the conservation ethic to people with more pressing problems.
The best-known way to see wild primates is to go to Volcanoes National Park in the central African country of Rwanda. There guides can lead you along trails to see the mountain gorillas made famous by the late primatologist Dian Fossey. Yet Rwanda, despite being only the size of New Hampshire, is the home of another group of primates that, while far less famous than the gorillas, are no less magnificent.
Discover, February 1, 1994
The fossil skull sitting on Alexander Kellner’s worktable makes no sense. Usually fossils are spark plugs in the engine of the imagination. One look at the long, gently curved bones of a spider monkey’s arm and you see a graceful swing from branch to branch; one glance at the weighty leg bones of a mastodon and you hear the rumble of a heavy stride. But this skull greets you with cognitive dissonance: all you see is essentially a flat triangle of bone. “A paleontologist once came in here and said, ‘What is that?’ ” says Kellner, himself a paleontologist at the American Museum of Natural History in New York.