How can black holes have no volume and infinte density yet have a finite mass?
In: Physics
What’s tripping you up here is that physicists don’t use the word “infinite” in *quite* the same way that mathematicians do. You could say that what black holes have is *undefined* density, because density is (mass / volume) and the volume is zero. And, of course, you can’t divide by zero. So regardless of what the mass is, the black hole’s density is undefined (or infinite, or unbounded).
The slightly more honest answer is that we don’t actually understand what that means in practical terms. It’s probably not *actually* a finite amount of mass with literally zero volume but that’s the best we can figure out with what we can currently observe. Black holes are weird, and the more we learn about them the weirder they get.
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