Why do we say black holes vanish if their mass decreases with hawking radiation?

[spidey]

it's been said because of hawking radiation,black hole evaporates and vanishes..but when black hole's energy is decreased by hawking radiation,its mass is also decreased,and at some point,it will have less mass and it cannot be a black hole and it should stop emitting hawking radiation then why we are saying black hole vanishes?

 

[mathman]

it will have less mass and it cannot be a black hole

Blackholes can be any mass (in theory) as long as the volume is sufficiently small. What happens inside a black hole is unsettled because quantum theory and gen. relativity don't work together. However, ignoring quantum theory, GR predicts that all the mass is confined to a single point, so that as it evaporates it remains a black hole.

 

[Dr_Zinj]

Quantum Black Holes?

I seem to remember that I read a SCIAM article several years ago that stated that quantum black holes would have been created during the Big Bang, but have all evaporated in the billions of years since then.

 

[shelanachium]

Crazy idea - but suppose when they find a workable quantum gravity theory, it turns out the minimum possible mass of a charged black hole is that of the electron?

 

[mathman]

Crazy idea - but suppose when they find a workable quantum gravity theory, it turns out the minimum possible mass of a charged black hole is that of the electron?

Black hole or not, the electron is the smallest charged particle there is, according to current theory.

 

[shelanachium]

That's the point. If it were also the smallest possible charged black hole as well, gravity and particle-physics would be happily married. But probably crazy, as I said. The smallest possible black hole more likely to be the Planck mass, very much more than that of the electron!