Question: what is a black hole ?

Cristina Villa del Campo answered on 8 Nov 2015:

Hi! Thanks for your question!

I’m afraid I am not an expert in black holes or space (although I find it fascinating and quite humbling, if you think of its vastness). I will try to answer your question in the best way I can. My understanding is that no-one has ever “seen” black holes. Physicists are able to know they are there by studying how the things around them behave. Black holes are places where matter is so dense that the gravitational forces are very very high, so high that nothing can escape them, they “pull” everything inside of them, even light and electromagnetic waves.
That’s all I can tell you! But know I am interested in knowing more! I guess I need to get reading.