Einstein’s gravitational redshift measured with unprecedented precision

Albert Einstein’s theory of general relativity makes a number of counterintuitive predictions about the workings of gravity, and experimentalists nearly 100 years after the theory was developed continue to confirm those predictions with increasing accuracy. A new paper co-authored by U.S. Energy Secretary Steven Chu measures the gravitational redshift, illustrated by the gravity-induced slowing of a clock and sometimes referred to as gravitational time dilation (though users of that term often conflate two separate phenomena ), a measurement that jibes with Einstein and that is 10,000 times more precise than its predecessor. [More]