What are facts about black-hole?

Answer 1

Here are some things that are currently unknown.

* How do supermassive black holes form?

* Are there intermediate-mass black holes? It seems there are, but this isn't very certain yet.

* Are there primordial (miniature-size) black holes? These may have formed during the Big Bang, but none have been found yet.

Answer 2

There are many interesting facts about black holes. They are:

1) It has infinite mass.

2) It has no Volume

3) It has infinite density

4) It seems black because not even light released by the black hole can escape from it. It absorbs the light because of its powerful gravity.

5) It has much gravity to hold a whole galaxy, that's how galaxies form with a super-massive black hole in the middle. However, our galaxy also have a super-massive black hole in the middle.

Answer 3

There are mysteries aplenty in the realm of scientific research regarding black holes. Much of the work is theoretical because of the difficulty of direct observation.

There is the information paradox - does information truly become lost since nothing can escape a black hole, while physical law forbids that information could simply ceases to exist.

Do primordial black holes leftover from the big bang exist, and if so, can we capture a signature gamma burst if and when they explode?

Does the event horizon actually exist? Hawking himself has revised his theories and brought this notion into question.

Do black holes have a form of parity with white holes, if so, can they be detected?

Could black holes be exploited as a power source, or as a time-travel device?

What is the mechanism that creates the ultra-powerful polar relativistic jets (as of black-hole powered active galactic nuclei and quasars)?

There are some far-out notions, like, could it be possible our universe is simply inside a black hole, or that a black hole inside our universe becomes another universe (since it should have an unlimited amount of stretched space, and to an observer inside a black hole, the uniform pull towards the singularity would become imperceptible)?

How do they form - more specifically there is a chicken-egg problem, does a supermassive black hole cause a galaxy, or does a galaxy create a supermassive black hole?

Then there's the youth paradox problem - can the gravitational pull of black holes prevent stars from forming; and if so, why do we have evidence they trap young stars?

There remain mysteries about the interaction of the gravitational pull and magnetic fields in the accretion disk; and even about how and why they can pull matter in.

Black holes remain enigmatic and likely will continue to be the subject of study for a long time.

Answer 4

Basically everything. Very little is actually known about black holes. Our current understanding is based on theory rather than by actual observations.