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Author Topic: How can black holes evaporate?  (Read 2454 times)

Offline Fozzie

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How can black holes evaporate?
« on: 01/12/2009 12:23:36 »
The often quoted evaporation of a black hole seems to be be contradictory to the way it works, so how can this happen?


 

Offline Mr. Scientist

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How can black holes evaporate?
« Reply #1 on: 01/12/2009 12:29:43 »
Yes. Evaporation happens but there is no loss of information.

You need to make your question a little more lengthier. I wasn't and still not sure wht your question is on the subject.
 

Offline PhysBang

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How can black holes evaporate?
« Reply #2 on: 01/12/2009 17:09:39 »
The often quoted evaporation of a black hole seems to be be contradictory to the way it works, so how can this happen?
The short answer is that it happens because at the quantum level the transfer of energy can take place over regions and these regions can overlap the event horizon of a black hole. For a longer answer, you need to research Hawking radiation.
 

Offline yor_on

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How can black holes evaporate?
« Reply #3 on: 02/12/2009 19:20:55 »
What you are referring to is hawking radiation.
http://physics.about.com/od/astronomy/f/hawkrad.htm

" Hawking predicted that energy fluctuations from the vacuum causes the generation of particle-antiparticle pairs near the event horizon of the black hole. One of the particles falls into the black hole while the other escapes, before they have an opportunity to annihilate each other. The net result is that, to someone viewing the black hole, it would appear that a particle had been emitted.

Since the particle that is emitted has positive energy, the particle that gets absorbed by the black hole has a negative energy relative to the outside universe. This results in the black hole losing energy, and thus mass (because E = mc2).

Smaller primordial black holes can actually emit more energy than they absorb, which results in them losing net mass. Larger black holes, such as those that are one solar mass, absorb more cosmic radiation than they emit through Hawking radiation.  "

What you need to observe here is that we are talking about 'virtual particles' created spontaneously due to the energy-mass relation between a black hole and the universe 'surrounding' it.

The more energy/mass the higher the probability of such particles. As they are created at the EV (event horizon) they 'belong' to our universe and the 'energy' lost by a black hole is due to the negative counterpart of that virtual particle pair in falling into the black hole. It is not any 'information' leaking out to our universe, rather a negation of mass/energy inside the EV due to the counterpart being 'negative' annihilating the 'positive' mass/energy.

As I see it.
 

Offline Webo

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How can black holes evaporate?
« Reply #4 on: 02/12/2009 20:22:29 »
Question:
1.) Any way of ever proving or finding these virtual particles? Again it sounds to me like a solution but not the truth? Also if they pop into existence which is very convenient, and one half shoots into space as a positive effect and one half falls into the black hole as a negative effect does that not leave us with zero effect? No increase and no decrease?
Thank You
Webo   
 

Offline yor_on

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How can black holes evaporate?
« Reply #5 on: 02/12/2009 22:54:05 »
First of all, the hawking radiation is still a theory unproven.

Virtual particles are a way of describing outcomes that otherwise becomes very strange. Invented by physicists in order to talk about processes in terms of the Feynman diagrams. http://en.wikipedia.org/wiki/Virtual_particle#Manifestations

So yes, we can see their outcomes even though we can't observe them directly as they exist for too short a time to be observable for us (HUP)
http://science.jrank.org/pages/7195/Virtual-Particles.html

They are a mathematical explanation firstly.

"but they are really only part of a quantum probability calculation. It is meaningless to argue whether they are or are not there, as they cannot be observed. Any attempt to observe them changes the outcome of the process"
 

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How can black holes evaporate?
« Reply #5 on: 02/12/2009 22:54:05 »

 

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