Naked Science Forum

On the Lighter Side => New Theories => Topic started by: MikeS on 29/08/2011 17:13:32

Title: Split from "Did Hawking Radiation change the entropic nature of black holes?"
Post by: MikeS on 29/08/2011 17:13:32
It was an open question for a long time if black holes obeyed the laws of thermodynamics.  Everything else we know does, so we figured they should--it would be odd if they didn't.  Hawking radiation gave a plausible mechanism that explains how they follow the laws of thermodynamics. 

What's also nice about it is that (as I understand it) he didn't invent new physical laws, but rather applied quantum mechanics to what general relativity told us about black holes at the event horizon.  So assuming GR and quantum mechanics are accurate theories, black holes don't break the laws of thermodynamics.  

If matter and antimatter are gravitationally repulsive (which is an open question) then a matter black hole will radiate antimatter particles from inside the event horizon and evaporate much quicker than by Hawkin radiation alone and this doesn't break the laws of thermodynamics either.
Title: Re: Split from "Did Hawking Radiation change the entropic nature of black holes?"
Post by: Robro on 29/08/2011 17:34:51
So the matter black hole will contain the annihilation reaction, inside the event horizon, of anti-matter particles being absorbed into it? Or will the annihilation happen AT the event horizon allowing some of the energy to escape and radiate away?
Title: Re: Split from "Did Hawking Radiation change the entropic nature of black holes?"
Post by: omen on 29/08/2011 22:17:42
It was an open question for a long time if black holes obeyed the laws of thermodynamics.  Everything else we know does, so we figured they should--it would be odd if they didn't.  Hawking radiation gave a plausible mechanism that explains how they follow the laws of thermodynamics. 

What's also nice about it is that (as I understand it) he didn't invent new physical laws, but rather applied quantum mechanics to what general relativity told us about black holes at the event horizon.  So assuming GR and quantum mechanics are accurate theories, black holes don't break the laws of thermodynamics.  

If matter and antimatter are gravitationally repulsive

I've not heard anything about such a reaction. There is no reason for them to be gravitationally repulsive. The distinguishing feature that sets these two examples of matter apart is only their electric charge. IMHO
Title: Re: Split from "Did Hawking Radiation change the entropic nature of black holes?"
Post by: MikeS on 30/08/2011 08:25:14
So the matter black hole will contain the annihilation reaction, inside the event horizon, of anti-matter particles being absorbed into it? Or will the annihilation happen AT the event horizon allowing some of the energy to escape and radiate away?

If matter/antimatter is gravitationally repulsive then pair particles formed within the event horizon will be gravitationally sorted.  The matter particles will be attracted to the singularity and the antimatter particles will be expelled through the event horizon carrying the energy of their creation away with them.  In this manner a black hole would loose mass.


If matter and antimatter are gravitationally repulsive

I've not heard anything about such a reaction. There is no reason for them to be gravitationally repulsive. The distinguishing feature that sets these two examples of matter apart is only their electric charge. IMHO

A reversal of charge can be viewed as a reversal of time.  Relativity and the laws of physics allow for such a possibility  but it is not a mainstream view.
Title: Split from "Did Hawking Radiation change the entropic nature of black holes?"
Post by: omen on 30/08/2011 23:13:17
A reversal of charge can be viewed as a reversal of time.  Relativity and the laws of physics allow for such a possibility  but it is not a mainstream view.
Personally, I think a reversal in charge has much more to do with spin than it does with time. Just my two cents............