What is a black hole?
A black hole is an object with such powerful gravity that nothing can escape from it, including light. ... More »
Do black holes really exist?
Probably. Astronomers have discovered quite a few objects that can only be explained as black holes.... More »
Are any black holes close to Earth?
The closest black holes yet discovered are several thousand light-years away. ... More »
Will our Sun become a black hole?
No. Stars like the Sun just aren't massive enough to become black holes. ... More »
What is the biggest black hole?
The largest known black hole appears to be about three billion times the mass of the Sun.... More »
What happens when you get close to a black hole?
The exact effects depend on the size and mass of the black hole.... More »
How does a black hole form?
A black hole forms when any object reaches a certain critical density, and its gravity causes it to collapse to an almost infinitely small pinpoint.... More »
Are black holes 'doorways' to other parts of the universe?
Only in science fiction. Anything that falls into a black hole is trapped there, and it cannot come out elsewhere in the universe.... More »
Can anything ever escape from a black hole?
Nothing that falls into a black hole can come back out again -- at least not in its original form.... More »
How many black holes are there?
To use a technical term, gobs.... More »
How can a black hole's own gravity, but not light, escape from it?
In the case of a black hole, it's best to think of gravity as Albert Einstein described it: a warp in space-time.... More »
Where did the name 'black hole' come from?
Princeton physicist John Archibald Wheeler coined the term in the 1960s.... More »
How are black holes named?
There is no unified naming system for black holes. ... More »
Will our universe become a black hole?
Unlikely. Recent developments that show our universe is expanding at an ever-increasing rate.... More »
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