1
$\begingroup$

If a black hole isn't "fed" by attracted matter, it disappears someday. But how is that even possible? What happens with the mass at its singularity? It can't just disappear or am I wrong with something? Where does the mass disappear to and how is it possible?

$\endgroup$
2
$\begingroup$

The mass (equivalently energy) is radiated away as Hawking radiation.

| improve this answer | |
$\endgroup$
  • $\begingroup$ But what happens with the matter from the singularity? $\endgroup$ – user30007 Feb 6 at 16:28
  • 4
    $\begingroup$ @user30007 Hypothetically, it's converted to energy and radiated away, as this answer says. I wrote "hypothetically" because Hawking radiation has never been observed. $\endgroup$ – David Hammen Feb 6 at 16:50
  • $\begingroup$ @DavidHammen, shouldn't that be, "Theoretically,...?" $\endgroup$ – Solomon Slow Feb 6 at 18:18
  • 1
    $\begingroup$ @user30007 The black hole singularity is also theoretical, and (hopefully) a quantum gravity theory will replace it. But in standard GR, a black hole singularity isn't like an object in space. Firstly, a singularity never exists in the past of any observer. And as described here "A singularity in GR is like a piece that has been cut out of the manifold. It's not a point or point-set at all". $\endgroup$ – PM 2Ring Feb 6 at 23:54
  • 3
    $\begingroup$ @SolomonSlow - No, it should not. People abuse the word theory so much that it now has come to mean "a wild guess made after having chugged one too many margaritas." A scientific theory is the pinnacle of science. A hypothesis: Not so much, and least not yet. Hawking radiation is a scientific hypothesis rather than a scientific theory. This hypothesis that has a solid basis in both general relativity and quantum mechanics, but it remains hypothetical. $\endgroup$ – David Hammen Feb 7 at 4:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.