Gravity-Detecting LIGO Also Found To Be Creating Gravity Waves

LIGO is a large-scale physics experiment to detect "ripples in spacetime," as well as gravity waves from outer space. But it turns out that it's also creating gravity waves, according to a team of physicists led by Belinda Pang, a physicist at the California Institute of Technology. sciencehabit quotes Science magazine:

Although these waves are far too feeble to detect directly, the researchers say, the radiation in principle could be used to try to detect weird quantum mechanical effects among large objects... Of course, LIGO doesn't generate large gravitational waves -- you could probably make bigger ones yourself by whirling bowling balls around -- but it does so with optimal efficiency [and] the waves could still be used to probe quantum effects among macroscopic objects, Pang says.

Quantum mechanics says that a vanishingly small object such as an electron can literally be in two places in once. Many physicists suspect that it might just be possible to coax a macroscopic object, such as one of LIGO's mirrors, into a similar state of quantum motion. That delicate state wouldn't last long, as interactions with the outside world would make it "decohere" and put it in one place or another. However, one could imagine measuring the rate at which such a state decoheres to see whether it matches the rate expected from the radiation of gravitational waves, Pang says.

"It's unbelievably difficult," Pang says. "But if you want to do it, what we're saying is that LIGO is the best place to do it."