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Gravitational Waves

January 23, 2012

The universe is vibrating like the inside of a concert hall where the orchestra is just warming up — a symphony of overlapping waves rippling through space itself.

No one has yet detected a single ripple, but scientists are looking for them. And their discovery would tell us about some of the most energetic events in the universe — and about the nature of the universe itself.

The “ripples” are known as gravitational waves. They’re predicted by general relativity — Albert Einstein’s theory of gravity.

Alan Weinstein is a physics professor at Caltech and a member of a science team that’s searching for these waves:

WEINSTEIN: Gravity is described, according to Einstein’s equations, as a curvature of space. Actually, that’s been well tested. We understand that very well. Gravitational waves is one of the major predictions that have not been tested. A gravitational field is a curvature of space, and a very rapidly changing gravitational field would produce ripples of curved space.

And David Reitze, also of Caltech, leads the team:

REITZE: The way to think about them is they’re literally changes in the distances between two objects. If I take a ruler and a gravitational wave passes it, the ruler will stretch and compress as the gravitational wave passes it. They're produced from accelerating masses, so when a car drives down the road, if it’s accelerating, it produces a gravitational wave. Unfortunately, that gravitational wave is very, very, very tiny. To detect measurable gravitational waves you need objects that are astrophysical. You need stellar-mass, super-stellar-mass objects that are moving near the speed of light.

More about that tomorrow.


Script by Damond Benningfield, Copyright 2011


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