When two black holes collide, the event can release gravitational waves
MARK GARLICK/SCIENCE PHOTO LIBRARY
We may have already seen black holes from the dawn of the universe, called primordial black holes. The Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and the Virgo observatory in Italy have detected 47 pairs of black holes slamming into one another, and a statistical study suggests that nearly one-third of them may be primordial.
Black holes can form through several different mechanisms. The main way is by a huge star collapsing in on itself, forming what is called an astrophysical black hole. Some …
source: newscientist.com