Pulsar Pair Backs Einstein
Score another one for general relativity. Albert Einstein's theory of gravity catapulted to fame in 1919 , thanks to measurements made during a solar eclipse.
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Score another one for general relativity. Albert Einstein's theory of gravity catapulted to fame in 1919, thanks to measurements made during a solar eclipse. Nearly a century later, researchers have used a similar trick on a pair of orbiting pulsars (spinning neutron stars) to see if the theory holds up when gravity gets really strong. Einstein's theory dictates that if two massive objects such as superdense neutron stars circle one another, each's gravitational tug should cause the other's spin axis to precess or wobble like a spinning top. To check the prediction, researchers monitored the pulsar pair PSR JO737-3039A/B, which orbit each other every 2.4 hours. The pair's orbital plane happens to line up just right with Earth so that one of them regularly eclipses the lighthouselike beam of light from the other, allowing researchers to glean information about the hidden pulsar's orientation and rotation. They reported in Science that the size of the precession—about five degrees a year—matched well with Einstein's theory.
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