The idea of a black hole was first predicted by Albert Einstein and his Theory of Relativity in 1915.Later in the century, 1971 to be exact, the first black hole, Cygnus X-1, was identified. This former binary star was observed by scientists, and it was emitting light waves that varied in luminosity every thousandth of a second. However, at the time, the term "black hole" was not the term used to describe Cygnus X-1. That term was first used by an American astrtonomer named John Wheeler.