Nearly a hundred years ago, Einstein put forth a theory that suggested the existence of gravitational waves, which alter space-time in massive astrophysical events.
According to the New York Times, such an astrophysical event (the collision of two black holes over a billion light years away) has been observed and is in agreement with Einstein's theory. The wave function which resulted from this event was observed by both the LIGO facilities in Livingston, Louisiana and Hanford, Washington. These reading were in agreement, giving great evidence that the theory could be a physical law.
Congratulations to the LIGO team and everyone involved in this groundbreaking observation!