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Catching the Waves with LIGO

PASADENA, Calif. – In 1916, Einstein predicted the existence of gravitational waves as a consequence of the general theory of relativity. In his theory, concentrations of mass (or energy) warp space-time, and changes in the shape of such objects cause distortions called gravitational waves. These waves propagate through the universe at the speed of light, and it's thought they are caused by cataclysmic events in deep space. These include black holes, spinning neutron stars, and perhaps even the Big Bang itself.

The Laser Interferometer Gravitational-Wave Observatory, or LIGO, is being developed to detect such gravitational waves, and on Wednesday, March 5, Barry Barish, the Ronald and Maxine Linde Professor of Physics and the director of the LIGO Lab at the California Institute of Technology, will explain how the detection of gravity waves will open a new window on the universe for astronomers. His talk, " Catching the Waves with LIGO," is one of the ongoing Earnest C. Watson Lecture Series that takes place on the Caltech campus.

The detection of such waves is an enormous challenge. The LIGO detectors consist of two observatories, one in the state of Washington, the other in Louisiana. To reach maximum sensitivity, LIGO employs a sophisticated, computer-based control system to position mirrors at the ends of two arms while bouncing a laser beam back and forth between them. The challenge is that the predicted motions of the mirrors due to even the strongest gravitational waves are incredibly small--about ten billionths of the diameter of an atom.

A successful detection would be big news, not the least of which would be the final confirmation of one of the fundamental predictions of Einstein's general theory of relativity.

Caltech has offered the Watson Lecture Series for over 80 years, ever since it was conceived by the late Caltech physicist Earnest Watson as a way to explain science to the local community. The lecture will take place at 8 p.m. in Beckman Auditorium, which is located near Michigan Avenue south of Del Mar Boulevard, on Caltech's campus in Pasadena. Seating is available on a free, no-ticket-required, first-come, first-served basis, beginning at 7:30 p.m. Parking is available in the lots south of Del Mar Boulevard between Wilson and Chester avenues, and in the parking structures at 341 and 405 South Wilson and 370 South Holliston Avenue.

For more information, call 1(888) 2CALTECH (1-888-222-5832) or (626) 395-4652. Persons with disabilities: 626-395-4688 (voice) or 626-395-3700 (TDD)

Contact: Mark Wheeler (626) 395-8733

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Written by Marcus Woo

Caltech Media Relations