View Full Version : Does quantum tunnelling permit escapes from black holes?

2009-Aug-07, 04:05 PM
My background is mechanical engineering, where neither relativistic nor quantum effects are significant (no nano for me ;)), and my search mojo is not world-class.

My question is, simply, can quantum tunneling permit matter/energy to escape from a black hole? Of course, if this is how black holes evaporate, I'm going to feel especially silly.


grant hutchison
2009-Aug-07, 08:44 PM
Hawking radiation seems to be most commonly described in terms of the black hole's tidal gravity splitting apart virtual particle/antiparticle pairs which spring into existence just outside the event horizon. One member of the pair falls across the event horizon, and the other escapes.
But Hawking has pointed out that an anti-particle can be thought of as a particle moving backwards in time. So we can also think of Hawking radiation as consisting of a particle which "tunnels" backwards in time across the event horizon, and which then flips into a more normal existence once safely out of the black hole.
Now, that's a different thing from "normal" quantum tunnelling, so I don't know if it would count, for your purposes.

Grant Hutchison

2009-Aug-08, 11:53 AM
Hawking radiation has been explained also as quantum tunneling:

The Parikh–Wilczek tunnelling framework, which treats Hawking radiation as a tunnelling process, is investigated once more in this work.