General relativity, the theory for which the German-born theoretical physicist is best known, holds up even in the more outlying phenomena of distant space, scientists have found.
Astronomers studied a neutron star about 7,000 light years from Earth that is twice as heavy as our sun but only about 12 miles in diameter. The gravity of this spinning, highly magnetic star, or pulsar, is about 300 billion times stronger than the force that’s holding your feet to the ground. A companion white dwarf is what remains of a much lighter star that is dying out.
The tightly spaced pulsar-dwarf pair, rotating around each other in under three hours, allows scientists to test alternative theories of gravity. It’s also a candidate for showing “deviations” in Einstein’s formulas. As the orbits decay, gravitational waves are emitted, sapping energy from the system. Astronomers used Einstein’s equations to calculate the amount of gravitational radiation emitted, then tested to see if it accurately predicted the rate of orbital decay.
"We thought this system might be extreme enough to show a breakdown in General Relativity, but instead, Einstein's predictions held up quite well," Paulo Freire of Germany's Max Planck Institute for Radioastronomy said in a written statement.