In 1918, Albert Einstein's theory of general relativity predicted that rotating bodies, such as black holes, drag space and time around itself as it rotates. In November of 1997, astronomers using NASA's Rossi X-ray Timing Explorer (RXTE) spacecraft made a startling discovery: evidence that supports this effect known as frame dragging.

Astronomers found evidence to support frame dragging by observing a binary star system in which a normal star feeds the disk of accreting matter spiraling into the event horizon of a black hole. In this particular case, the astronomers were observing two black holes: GRS 1915+105 and GRO J1655-40 (Dooling).

The astronomers calculated the oscillations being caused by frame dragging making the accretion disk precess. Precession, according to Dave Dooling, is "seen when a toy top both spins rapidly about its own axis, yet at the same time, executes a slower circular motion about the lower vertical axis. This second circular motion is precession, and it's not only found in toy tops, but also . . . [in] accreting disks around black holes in distant space."