A billion years ago, 2 black holes collided.
The violent event created "gravitational waves" -- a ripple in space-time.
In September, researchers at the Laser Inter-Ferometer Gravitational Wave Observatory or "LIGO" heard that wave.
"Oh my gosh this is real. It took us 25 years and 2 detectors to finally detect a gravitational wave," said LIGO executive director David Reitze.
Reitze got his PHD in Physics from the University of Texas in 1990.
Back here in Austin, researchers at UT are thrilled about the discovery.
"It completely proved Einstein's idea about general relativity and the existence of space-time. That's phenomenal," said Dr. Karl Gebhardt, an Astrophysics professor at UT.
Dr. Gebhardt is an expert on black holes.
"What is happening is as they go through space they are distorting space. It's kind of like taking a bed sheet and flapping it and you cause this vibration. That takes energy, that's why they're coming together. But then that vibration, that space, that movement of space traveled for a billion light years, came to Earth and it wobbled that instrument: LIGO." Gebhardt said.
Just a little refresher -- what is a black hole again?
Let's just say for a minute, I'm standing inside a black hole. Dr. Gebhardt says if you were to shine a laser pointer into the void, in theory it would come back around and hit you in the back of the head.
Even though the existence of black holes is a known-fact, the laser-pointer trick is still just a theory. But thanks to this discovery, it may not be for long.
"We don't have confirmation of what goes on inside of a black hole but I can say for sure this stuff that's coming out of LIGO, this data that's coming out of LIGO right now is going to test that at remarkable precision and so I think we're going to get there relatively soon," Gebhardt said.
UT Physics professor Dr. Willy Fischler says the study of gravitational waves will shed some light on the origins of the universe.
"This is a spectacular discovery but it becomes a tool in the future. It may be a tool for us to look at the universe in a way that we don't have the capabilities yet," Fischler said.
Fischler says learning something about nature is an uplifting thing in a sea of tragedy around the world.
"Discovering some feature about how she behaves...I think it's just uplifting. It made my day. It really made a lot of people's day," Fischler said.