Every galaxy has a supermassive black hole at the centre of it The galaxy NGC 6240 within the Ophiuchus constellation, is a super galaxy that was formed as a result of two smaller galaxies colliding with one another
As a result, NGC 6240 has not one, but two supermassive black holes at its centre Astronomers believe that one day these two black holes may very well collide with one another So what would happen if two black holes collided? The collision of two black holes is such a rare event that it has never actually been observed by scientists here on Earth We have however, ran extremely complex computer simulations to determine what the result would be if two black holes did collide Firstly it's important to understand the enormity and sheer density of black holes
A typical supermassive black hole can have a mass anywhere from many millions to several billion times the mass of our sun The largest black hole we have ever found is in the galaxy Holmberg 15A The blackhole at it's core is 15,000 light years across and has an estimated mass of 170 billion times that of our sun – or most properly referred to as 170 billion solar masses So what would happen? Well there's basically two possible outcomes of such a catastrophic event Which possibility depends on the speed at which the two black holes are traveling, how fast they are spinning, and the angle of their collision
If the two black holes are spinning at very high speeds and come together at just the right angle, the smaller black hole will be slingshotted away from the bigger black hole and sent hurtling through space Similar to how two spinning tops bounce off each other when collided But the second, more likely outcome is that they will slowly come closer and closer together until they can't escape each other's gravity and they eventually become one This process would be unbelievably violent When this happens the resulting black hole is known as a "Binary Black Hole"
As the two black holes start to merge they would appear to be a distorted mess of matter But as they come closer and closer together the resulting black hole goes through a process known as "ring-down" This is when any distortion in the shape is slowly dissipated and the new binary black hole becomes more and more circular Until any asymmetry is lost and the black hole, once again becomes a nearly perfectly circular disk of swirling death The energy emitted from the collision would be so great that it would send ripples through the space-time fabric of the Universe
Just think about that for a second, two black holes colliding would cause the very fabric of the Universe, space and time, to ripple, like a gigantic pebble in a pond These ripple are known as "gravitational waves" Gravitational waves have never been observed here on Earth In recent years we have built large instruments on Earth that are capable of detecting gravitational waves far away in space And even more powerful instruments are currently under construction
Why is it so important that we detect these waves? Well gravitational waves are a fundamental component of Einstein's theory of general relativity Detecting them and thus proving their existence would be irrefutable evidence to backup Einstein's theory As well as increasing our understanding of gravity and how it behaves So to summarise, if you see two black holes about to collide, get the hell out of there