2 black holes collided billions of years ago. The spectacle is just beginning to reach Earth.

In a galaxy far, far away, two giant black holes appear to be circling each other like fighters in a galactic boxing ring. Gravity is causing this death spiral, which will result in a collision and formation of a single black hole, a massive event that will send ripples through space and time.  The collision itself happened eons ago — the two black holes are located about 9 … Continue reading 2 black holes collided billions of years ago. The spectacle is just beginning to reach Earth.