Black hole mergers are beautiful. And it’s also the most violent event in the universe. Here’s how the process unfolds:
The story begins with two people black hole They orbit far away from each other in long, lazy circles. They may have been born as a pair of binary stars, or they may have just happened to meet in the depths of space. interstellar space. Either way, they have to get closer to merge, which means losing a lot of orbital energy.
The first step in stealing energy from a system is through the interaction of the black hole with its surroundings. They are not alone. There are always thin pieces of gas and dust floating around, and sometimes larger objects such as planets or planets. star. All these objects interact through: gravitation With black holes. Sometimes they fall out and are never seen again. In other cases, it speeds up slightly and sloughs off some of the orbital energy from the black hole, causing a narrow miss.
When the black hole gets close enough, other processes take over. black hole churning space–hour As they orbit each other, this agitation is released. gravitational waves It comes from the pair like ripples in a pond. But gravitational waves are incredibly weak, and they only start to seriously drain energy when black holes are very close to each other.
relevant: How dancing black holes get close enough to merge
This leaves astrophysicists with a conundrum.final parsec problem.” Simulation results show that gravitational interaction with the environment can bring a black hole to within about 1 meter. parsec (about 3.26 light years) each other within a reasonable amount of time. But there isn’t enough matter within that distance to continue to attract energy. On the other hand, at the same distance, gravitational waves are so weak that several times as many gravitational waves are needed. age of the universe To get the job done.
The final parsec problem is currently an unsolved mystery. astrophysics. But whatever mechanism occurs, the black hole eventually gets close enough that gravitational waves can actually extract a lot of energy from the system. At this point, the black holes only have a few seconds to merge.
At such close distances, black holes begin to transform into each other. There is actually no surface. The event horizon is an invisible border that marks an area from which there is no escape. But the shape is event horizon It depends not only on the black hole itself, but also on the surrounding space-time geometry. So when black holes begin their deadly dance, their event horizons stretch towards each other.
We understand what happens next only through complex computer simulations that monitor and track the evolution of the event horizon. In the milliseconds before collision, each black hole sends out thin tendrils (small tunnels in the event horizon) toward its companion. These tendrils meet and merge to form a bridge between the two black holes, as if they were connected by an umbilical cord.
Very quickly the legs widen and the event horizons stick together, like two colliding soap bubbles. In an instant, the black holes merge into one.
What happens inside is anyone’s guess. that center of black hole It is known as the Singularity, the point at which density is infinite. This is where our current understanding of physics falls apart. Simulations show that the singularities quickly find each other, orbit briefly, and then merge. But it’s unclear what actually happens.
Strangely enough, the mass of the newly merged black holes is less than the combined masses of the original pair. For example, in 2016 rigo scientific cooperation First gravitational wave phenomenon detected. Through black hole mergers, it was discovered that a black hole with a mass of 36 times the solar mass merged with a black hole with a mass of 30 times the solar mass, creating a new black hole with a mass of only 63 times the solar mass.
What happened to the three extra solar masses? That mass was converted into energy in the form of gravitational waves. Someone had to pay for all the energy loss, and it came from the transformation of the black hole mass itself. In all black hole mergers, about 5% are converted into gravitational waves.
To put it into perspective, this is like converting three entire suns into pure energy. When black holes collide, they release more energy than all the stars in the universe. All this happens in complete and utter silence and darkness.
