In 1916, Albert Einstein predicted that violent cosmic motions should send gravitational waves rippling through the fabric of space. Today, researchers inaugurate an unusual observatory designed to catch those elusive waves. The $292 million Laser Interferometer Gravitational-Wave Observatory (LIGO)--which has facilities in Livingston, Louisiana, and Hanford, Washington--will use laser beams to continually measure the positions of mirrors suspended in vacuum tubes 4 kilometers apart. Researchers hope the delicate detectors can discern relative wiggles as small as 1/10,000th the diameter of a proton.
"I can't imagine a more exciting new window to open on the universe," says Caltech physicist Gary Sanders, LIGO's deputy director. But LIGO probably won't sense any shimmers in space-time until both facilities are fine-tuned and ready to start eyeing the gravitational universe in early 2002.