but what would happen?

They would merge into a larger black hole

or would one just suck in the other

Absorbing the mass of the first one and essentially merging with it

They collide and then merge. The merger creates gravity waves (since light can't escape, we can't see it happen). We just now have the ability to detect the gravity waves.

You can learn more here: https://www.nature.com/articles/d41586-020-02524-w

black holes don't "suck" stuff like in movies. If the sun turned into a black hole, the earth would still orbit it. but if they collided they would merge.

Ok beez

ok

The Earth would very, very slowly get closer to the sun because of it's gravity. Eventually, when it got too closely drawn to the "Sun", it would inevitably be destroyed because of how time and space act in a black hole.

Here’s the gravity of the situation(see what I did there?). A black hole’s gravity is so dense it can suck in light. Anything that crosses the event horizon is doomed to get sucked in. The smaller the black hole, the denser it is. So if the sun exploded and turned into a black hole. We’d be dead before the black hole would even appear

It's simple. They'd merge into one.

something else would happen...

maybe they would combine to make a mega black hole and eat the galaxy

Well, there IS a phenomena called "galaxy cannibalism". The phenomena is when a larger galaxy absorbs a smaller galaxy. It could be the same with black holes.

MANY gravitational waves, and some crazy space-time warping. In the end, there is a black hole with just under the mass of the original 2 combined. Some was lost to gravitational waves.

wouldn't it cause a super nova

no

a super nova is when a star explodes and the result of it is...a supernova..yippee

It would collide and become one, this would also cause one of the loudest sounds ever discovered.

It would create an explosion while merging into a larger black hole and it would release a blast of gamma rays ( I think ).

Very close, When two black holes spiral around each other and ultimately collide, they send out gravitational waves - ripples in space and time that can be detected with extremely sensitive instruments on Earth. ... If confirmed, it would be the first known light flare from a pair of colliding black holes

Okay

it has happened before but it created super powerful magnetic force and we detected it only a few years ago. but if were on about supermassive black holes it would probaly destroy most gravitational forces the magnetic force it would create of ever tear apart worlds.

I watched a video on this just the other day: https://www.youtube.com/watch?v=iLKTZr00xBg