Four Keys to Cosmology; February 2004; Scientific American Magazine; by George Musser; 2 Page(s)

For cosmologists, it was like stepping on the brakes and feeling the car speed up, an exhilarating but disconcerting sensation that something wasn't working quite as it should.

In what is widely regarded as the most important scientific discovery of 1998, researchers turned their telescopes to measure the rate at which cosmic expansion was decelerating and instead saw that it was accelerating. They have been gripping the steering wheel very tightly ever since.