# What would happen if two black holes collided?

• ocalhoun
In summary, the conversation discusses the possibility of two black holes colliding and reaching the speed of light. However, due to the effects of relativity and the increasing mass and gravitational force, it is not possible for them to reach the speed of light. Additionally, the concept of black holes being much more compact and having stronger tidal forces is also mentioned.
ocalhoun
This problem is an interesting one (at least for me), and I wonder if ya'll will have any insights into it...

Suppose two black holes were on a collision course with each other. As they get closer, their combined gravitational force causes them to accelerate. As they accelerate, due to relativity, their mass increases, as their masses increase, their gravitational force increases (right?) As their gravitational force increases, they accelerate more. So, could they eventually get to the speed of light?

Their mass would then be infinite, so it would take an infinite force to accelerate them, but their mass being infinite, their gravity would also be infinite, causing the force accelerating them to be infinite as well...

.9999 light speed maybe but not over
I think the key to a super masive BH
is in collisions growing the mass

maybe a quasar too

Pair of approaching black holes?

Hi, ocalhoun,

ocalhoun said:
Suppose two black holes were on a collision course with each other. As they get closer, their combined gravitational force causes them to accelerate. As they accelerate, due to relativity, their mass increases, as their masses increase, their gravitational force increases (right?) As their gravitational force increases, they accelerate more. So, could they eventually get to the speed of light?

The short answer is "no". Similar issues are addressed in the sci.physics FAQ; see http://www.math.ucr.edu/home/baez/physics/Relativity/SR/mass.html and http://www.math.ucr.edu/home/baez/physics/Relativity/BlackHoles/black_fast.html

It is often helpful to think of black holes as behaving pretty much like a "dark" object with the same mass and angular momentum. What makes a black hole different from an ordinary star in its interactions with other objects is that it is much more COMPACT, which means that you can get much closer without hitting it and thus experience much strong tidal forces than you can experience outside the surface of an ordinary star.

Chris Hillman

Last edited by a moderator:

## 1. What exactly is a black hole?

A black hole is a region in space where the gravitational pull is so strong that nothing, including light, can escape from it. It is created when a massive star collapses in on itself during the end of its life.

## 2. What would happen if two black holes collided?

If two black holes were to collide, they would merge together to form a larger black hole. This process would release an enormous amount of energy in the form of gravitational waves.

## 3. How often do black holes collide?

As black holes are constantly moving and interacting with other objects in space, collisions between them are rare but not impossible. However, the detection of gravitational waves in recent years has provided evidence that black hole collisions do occur.

## 4. What would be the impact of a black hole collision on nearby objects?

The intense gravitational forces of a black hole collision would cause massive disruptions and distortions in the surrounding space, potentially affecting nearby objects such as stars and planets. The energy released from the collision could also produce powerful jets of radiation.

## 5. Can a black hole collision affect Earth?

It is highly unlikely that a black hole collision would directly affect Earth as the closest known black hole is thousands of light years away. However, the gravitational waves produced by a collision could potentially be detected by instruments on Earth.

• Astronomy and Astrophysics
Replies
4
Views
190
• Astronomy and Astrophysics
Replies
4
Views
1K
• Astronomy and Astrophysics
Replies
4
Views
1K
• Astronomy and Astrophysics
Replies
5
Views
1K
• Astronomy and Astrophysics
Replies
4
Views
1K
• Astronomy and Astrophysics
Replies
10
Views
1K
• Astronomy and Astrophysics
Replies
12
Views
1K
• Astronomy and Astrophysics
Replies
1
Views
1K
• Astronomy and Astrophysics
Replies
11
Views
3K
• Astronomy and Astrophysics
Replies
27
Views
3K