Sunday, October 26, 2014

Einstein's Gravity Waves Could Be Found with New Method

This illustration depicts the gravitational waves generated by two black holes orbiting each other.

Credit: NASA

Gravitational waves, invisible ripples in the fabric of space and time, might be detected by looking for the brightening of stars, researchers say.

These mysterious ripples were first proposed by Albert Einstein as part of his theory of general relativity. The waves' size depends on the mass of the objects creating them.

"Gravitational waves are emitted by accelerating masses," said lead study author Barry McKernan, an astrophysicist at the American Museum of Natural History in New York. Really big waves are emitted by really big masses, such as systems containing black holes merging with each other.

Scientists have still not made direct observations of gravitational waves, although researchers continue to endeavor to detect them using experiments involving lasers on the ground and in space. The waves interact very weakly with matter, which partly explains why seeing these ripples in spacetime is difficult.

Now, McKernan and his colleagues suggest that gravitational waves could have more of an effect on matter than previously thought, with their influence potentially brightening stars.

"It's neat that nearly 100 years after Einstein proposed his theory of general relativity, there are still interesting surprises it can turn up," McKernan told "We're brought up as astronomers thinking the interaction between matter and gravitational waves is very weak, essentially negligible, and that turns out not to be true."

The researchers suggest that stars that vibrate at the same frequency as gravitational waves passing through them can absorb a large amount of energy from the ripples.

"You can imagine gravitational waves as sounds from a piano, and stars as a vibrating violin string held near that piano," McKernan said.

"If the frequency of the sounds matches the frequency of the violin string, the string can resonate with the sound." If a star gets pumped up with large amounts of energy from gravitational waves in this way, "the star can puff up and look brighter than it normally would," McKernan said.

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