[katieHaylor (OP)]

John asks:

We're told that in the centre of a black hole is a gravitational singularity, a one-dimensional point which contains a huge mass in an infinitely small space, where density and gravity become infinite and space-time curves infinitely, and where the laws of physics as we know them cease to operate.

If density and gravity become infinite, how can more than one black hole exist? And what about those microscopic black holes that the Large Hadron Collider at CERN may (or may not) produce? Don't those microscopic black holes have infinite density and gravity?

Even if it's possible to have different black holes with infinite density and gravity, why isn't all matter attracted to this infinite gravity, whatever the 'size' of the black hole?

What do you think?

[jeffreyH]

No one knows what happens beyond the event horizon of a black hole. What the mathematics tell us and what actually occurs may be completely different. The gravitational force is inverse square in nature meaning that its strength is inversely proportional to the square of the distance from the source. A black hole cannot alter this. If you were at a particular distance from a black hole before it collapsed then you would remain at that distance after it collapses. As long as you aren't near enough to the black hole to be destroyed in the supernova. So the earth and the whole Milky Way remain in place despite there being a supermassive black hole at the centre of our galaxy.