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Author Topic: Do black holes die?  (Read 2263 times)

Offline Novacaine

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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

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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.


Offline imatfaal

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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

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Do black holes die?
« Reply #2 on: 25/03/2011 17:09:22 »


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