,,When giant black holes collide, the surrounding space-time trembles,,
The collision of two supermassive black holes in the aftermath of a galaxy merger is the ultimate cosmic cataclysm, throwing out more energy for about an hour than all the visible stars in the entire universe combined. Moreover, in order to form the billions of majestic galaxies scattered across the sky, astronomers think that such events must have happened frequently as the first galaxies consolidated and grew.