Scientists Counted 20 Billion Ticks of an Extreme Galactic Clock to Test Einstein's Theory of Gravity

For more than 100 years, Albert Einstein's general theory of relativity has been our best description of how the force of gravity acts throughout the universe. General relativity is not only very accurate, but ask any astrophysicist about the theory and they'll probably also describe it as "beautiful." But it has a dark side too: […]