Do black holes die?

  • 2 Replies

0 Members and 1 Guest are viewing this topic.


Offline Novacaine

  • Jr. Member
  • **
  • 10
    • View Profile
Do black holes die?
« on: 25/03/2011 15:50:45 »
 Well, I just wonder if those monsters can die, and if they do, whats happening to all the matter they have swallowed through their lifetime? Is there any theory or a proof about that?
« Last Edit: 25/03/2011 15:58:40 by Novacaine »


Offline neilep

  • Withdrawnmist
  • Naked Science Forum GOD!
  • *******
  • 20602
    • View Profile
Do black holes die?
« Reply #1 on: 25/03/2011 16:19:39 »
There's theory known as Hawkings Radiation......I'd wait for some clever responses if I were you but lets just say that after an exorbitantly length of time it is postulated that they eventually evaporate. It takes such a long time that any big black holes out there would not have been round long enough to have evaporated away yet.

Men are the same as women, just inside out !


Offline imatfaal

  • Neilep Level Member
  • ******
  • 2787
  • rouge moderator
    • View Profile
Do black holes die?
« Reply #2 on: 25/03/2011 17:09:22 »
NovaC - there is definitely no proof.  As sheepy said there is Hawking radiation - but it must be understood that any self-respecting decent-size black hole is actually colder than the background radiation and thus is in a state of net gain, and will be for many billions upon billions of years until the average temperature of the universe drops. 

To explain a bit more: anything colder than its environment will be a net gainer of energy and anything hotter will be a net exporter.  Black holes have a temperature that is higher than zero but less than the temperature of deep space (which is still heated by the leftovers of the big bang).  So whilst Hawking radiation gives a blackhole a method to lose energy/mass - most will not actually do so until the universe has spread out much more and cooled down considerably.   

Soulsurfer has a superb link (which I keep on losing ) that allows you to calculate the variables of a blackhole from certain parameters.  Hopefully he will post it :-)  Unless a blackhole's temperature is greater than 2.725K it will gain energy on average - you can use this figure to understand how small a black hole needs to be in order to boil away in the present universal conditions
Thereís no sense in being precise when you donít even know what youíre talking about.  John Von Neumann

At the surface, we may appear as intellects, helpful people, friendly staff or protectors of the interwebs. Deep down inside, we're all trolls. CaptainPanic @ sf.n