View Full Version : trying to understand... please help me out
2004-Jul-22, 01:14 PM
Please help me out. I'm trying to understand Hawking radiation. When the particle anti-particle is created is it only chance that determins which of the two falls into the black hole and which of the two escapes? If it is by chance then is the eventual evaporation of a black hole determined by the happen stance of more anti-particles falling in than normal particles. If an anti-particle escapes and the particle falls in does the black hole gain mass? Is there a probability ("remote" doesn't adequately characterize it) that a black hole could spontaneously create enough quantum pairs at the horizon and where all particles falling in were anti-particles to instantly pop the black hole out of existance. Can any of these remote probabilities be calculated for a given black hole mass. Is it possible that the big bang was merely a lowest probability quantum event?
2004-Jul-22, 01:53 PM
It doesn't matter which of the two virtual particles falls into the black hole. Both the particle and the anti-particle have the same mass. The energy loss for the black hole comes from the energy required to create the virtual particle pair.
2004-Jul-22, 03:52 PM
You only need to post this once.
2004-Jul-22, 04:05 PM
1) The virtual pairs occur everywhere, randomly. The black hole doesn't create them, nor does it even act as a site of unusually high activity (i.e. it isn't a "magnet" for them either).
2) It doesn't matter which one falls in. The BH loses the energy when it seperates the virtual pair, keeping them from recombining. It does this by sucking one of them in, but not the other. In seperating the pair it has to expend energy (just like a person expends energy stretching a spring). And since one of the particles doesn't enter, it effective lost it, never to be regained.
In that aspect it "created" a new particle, outside the Event horizon. It just shed an an atom, and loses mass.
2004-Jul-22, 07:36 PM
Ricimer, are pairs created uniformly everywhere all the time or are they randomly created in both space and time... from what you wrote i would guess the latter
2004-Jul-22, 08:43 PM
Well, it is the latter (they occur randomly everywhere), but the effect (what we see) is the former.
If something is equally likely to occure anywhere, and if you have enough random events, the distribution will appear uniform.
2004-Jul-22, 08:51 PM
i guess i'm fiddling with the density of matter/anti-matter particle creation... i believe that i understand what you are saying in that they are created completely at random and in no way related to the existance of event horizons... it is only the event horizons that cause the random creations to not be instantly annihilated... there must be (surely) density issues involved with creations though.... more created here than there for a given time interval
2004-Jul-23, 12:41 AM
Since no one else pointed it out...
The force making the virtual particles is the Casimir Effect. Its well tested and thought to be a verified force.
So my question is... If over the mileu black holes tend to evaporate, do they go out with a bang or a wimper?
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