**Ask a monkey a physics question thread**

[OngBonga]

Do black holes have measurable mass or energy?

We can measure its gravity, so certainly.

When they swallow stars and galaxies do they not break the first law of thermodynamics for the closed system of the universe?

This is more complex and I should probably leave this to mojo. But I won't.

I don't think so. Because it has gravity, its mass still exists in this universe, it remains part of the closed system that is the universe. It hasn't gone anywhere. The total mass/energy of the universe remains unchanged.

The question for me really is... does a black hole occupy space?

If not, does it travel through space? Or does space travel around it? Is there even a distiction between those two concepts?

[chemist]

The question for me really is... does a black hole occupy space?
If not, does it travel through space? Or does space travel around it? Is there even a distiction between those two concepts?

As things go in they massively stretch so space and time are being distorted, to some frames of reference, but I don't know what that really means.

[MadMojoMonkey]

As things go in they massively stretch so space and time are being distorted, to some frames of reference, but I don't know what that really means.

If I may...
As things go in they (appear to) stretch (according to a stationary observer, far from any event horizon) because spacetime is distorted by the extreme mass of the black hole, but I have no intuition which helps me understand this.

Stretching of spacetime is caused by the mass of any object. Mass curves spacetime, and the curves in spacetime express forces on masses... this is how GR describes gravity.

[chemist]

If I may...
As things go in they (appear to) stretch (according to a stationary observer, far from any event horizon) because spacetime is distorted by the extreme mass of the black hole, but I have no intuition which helps me understand this.

You may, because I did already say, 'to some frames of reference', ie for example the frame of reference (according to a stationary observer, far from any event horizon) among perhaps others, , but thanks for making it specific and thus clearer.