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Wobbly Clocks

May 11, 2012

Pulsars are some of the most bizarre objects in the universe. And an experiment that’s being developed now may allow scientists to use pulsars to confirm a prediction in Albert Einstein’s theory of gravity.

A pulsar is the tiny, ultradense core of a dead star. Some pulsars spin up to hundreds of times per second, beaming energy into space like a cosmic lighthouse.

The timing of these “pulses” of energy is so precise that pulsars are some of the best clocks in the universe. And astronomers may be able to use those clocks to detect something predicted in Einstein’s equations: gravitational waves. Richard Price of the University of Texas at Brownsville explains:

PRICE: We can detect these pulsars as if they were perfect clocks fixed at a point in the universe. When we see some sort of variability in that timing, we can, in principle, infer that that variability is due to the passage of a gravitational wave between us and the pulsar.

Gravitational waves are “ripples” in spacetime caused by the motions of massive objects. There’s evidence that they exist, but no proof.

As they move through space, they change the distances between objects by a tiny amount. The pulsar experiment is designed to detect very long waves, which should be produced by monster black holes in distant orbits around each other. Such waves may also be left over from the Big Bang.

If the experiment works, it would provide one more confirmation of Albert Einstein’s theory of gravity.


Script by Damond Benningfield, Copyright 2012


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