What happens when two black holes collide?

Question

O.o

I heard a lot of people saying "they will combine" but is the possible? I thought black holes are infinitely dense. Is it possible to combine two infinitely dense entities? Also, what happens to the objects that the black holes have pulled in?

Answer 1

In the void of space, black holes are (comparatively) very tiny objects. If two black holes approach each other, it is likely that they will circle each other before merging.

As they orbit each other, the pair will emit gravitational waves. As energy is emitted as gravitational waves, the orbits get smaller and smaller (the energy for the waves is taken from the orbital momentum).

When they merge, they simply become one black hole whose mass is the sum of the two precursor black hole (plus whatever else falls in during the process).

Because of the tight orbiting that goes on just before the merger, the new black hole will be a rotating black hole (whether the old ones were or not).

If we could detect gravitational waves (we have not been able to, yet), the frequency emitted by spiraling black holes would increase very fast in the seconds before the merger. That is because the smaller and smaller orbits have much shorter periods.

Then, after one bigger wave, there would be a train of waves with another shape (resembling that of sound waves from a bell): the newly formed black hole would "ring" for a very short time.

Answer 2

When the black holes get as close as 1 light-year apart, they will begin to merge.They would spiral towards each other.The final merging of the black holes, to form a single one of larger mass, will be accompanied by an enormous burst of gravitational waves.These waves will spread through the universe, causing ripples in the fabric of space that astronomers would be able to detect as tiny changes in distance between two points.Meanwhile, theres more to the merger. During the final stages, more and more gas rains down on the two black holes.The gas will heat itself up in the process, and start to emit huge amounts of radiation, strongly increasing the luminosity of the nucleus of the galaxy, outshining the whole galaxy in its brightness by a large factor. The strong radiation field will start to destroy the dust in the environment of the nucleus, giving an outside observer an even clearer view on the nucleus of the galaxy.When all is said and done, few stars are likely to remain in the vicinity of the merged and more massive black hole.....

Answer 3

I think it's a perfectly inelastic collision, with conservation of linear and rotational angular momentum. The changing topography of the merging event horizons on the approach to collision might be interestingly complicated. The two will form a single new black hole having the sum of the masses of the earlier ones (so energy is conserved too).

Answer 4

We have never witness that so no one can tell for sure. All we have are conjectures. One of four things can happen:

1- They both destroy (cancel out) each other
2- They sum each other
3- they merge into one exactly the same (no change)
4- Some thing completely wild and unexpected.

If 1,3 or 4 happen then our astronomers and physicists will be reworking their math for the next 100 years in an attempt to make the numbers match the observations. It wouldn't be the first time.

Answer 5

They eventually merge into a single black hole with much greater mass than either of the two individual black holes. And yes, black holes do move and they do collide.

Answer 6

i do no longer understand approximately merging, however the concept of them orbiting one yet another for a while is extra achievable on the 2d. The galaxy andromeda easily has 2 great huge black holes orbiting one yet another on the middle of the galaxy, indicating andromeda has swallowed yet another galaxy, black hollow and each little thing. Milky way galaxy is next via the way.

Answer 7

ALL WRONG.

MY PROF FOUND THIS OUT!!

WHat happens is they fall into orbit with each other, which then slingshots planets around them. I'll explain, if a body is travelling towards it, the combined pull or the orbit of the black hole and the orbit of the two holes, then it slingshots the planet around the hole and accelerates the planet to a higher speed than before in a perpendicular path.

Answer 8

They combine to form a single, bigger black hole with more gravitational pull.

Answer 9

they don't move, so that couldn't happen