Two black holes, each with accretion disks, are illustrated here just before they collide. The inspiral and merger of binary black holes provided humanity with our first direct measurement of ...

Albert Einstein can rest a little easier: The first effort to measure how quickly gravity exerts its influence indicates that it more or less matches the speed of light, scientists reported Tuesday.

COLUMBIA, Mo. – Scientists have attempted to disprove Albert Einstein’s theory of general relativity for the better part of a century. After testing and confirming Einstein’s prediction in 2002 that ...

In Newtonian physics, gravity was thought to be instantaneous. But in Albert Einstein’s general theory of relativity, the speed of light, c, is the fastest possible speed for any interaction that ...

In the zero-gravity airplanes or vomit comet, why does stuff behave like there is no gravity when it is just falling? – Austin B., 11, Scranton, Pennsylvania I have flown many times in zero-gravity ...