The Penrose Process

Foxbat

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RJM Corbet

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RJM Corbet

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Both processes result in a reduction of rotational energy of the black hole ...
They do? That's interesting.

...not that I know an awful lot about it ...
Nor me, lol.

But as far as I understand Hawking radiation can be thought of as a result of a virtual particle pair originating close enough to the event horizon that, instead of mutually annihilating one another -- one half of the pair is captured by the black hole while the other escapes as an 'actual' particle -- as Hawking radiation?
 

mosaix

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We discussed this back in 2013...


What I didn't understand then, and don't understand now, is that why is it that it is always the negatively charged particle that is the one that falls into the black hole?
 

Ursa major

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why is it that it is always the negatively charged particle that is the one that falls into the black hole
It lacks the necessary positive attitude...?

I thought (not that I think about this a lot, as it very soon fries my brain) it was, in theory, the particle with "negative mass" that falls into the black hole; otherwise the black hole would not lose mass when the paired particles are separated.
 

RJM Corbet

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We discussed this back in 2013...


What I didn't understand then, and don't understand now, is that why is it that it is always the negatively charged particle that is the one that falls into the black hole?
It lacks the necessary positive attitude...?

I thought (not that I think about this a lot, as it very soon fries my brain) it was, in theory, the particle with "negative mass" that falls into the black hole; otherwise the black hole would not lose mass when the paired particles are separated.
Heavy stuff.

Perhaps it is just a Feyman diagram all possible paths way of proposing via virtual particles how a black hole leaks a 'real' photon? Which it does do? So it is a theoretical means of explaining the possible process behind the actual event?

Virtual particles being the conjectural link between real particle interactions? But why can't it happen the other way around? Could a 'matter' black hole 'leak' antimatter?

Way over my head, lol ...
 
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hitmouse

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We discussed this back in 2013...


What I didn't understand then, and don't understand now, is that why is it that it is always the negatively charged particle that is the one that falls into the black hole?
It isn’t.

@Ursa major Antiparticles do not have negative mass.

@RJM Corbet Yes. By the same process, black holes can “ leak “ antimatter.
 
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pyan

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I'm sure that it's very important that we understand the process - but I'm afraid my first reaction was "Oo-er, DM!"...
 

Ori Vandewalle

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The virtual pair splitting near the event horizon explanation is an analogy gone wrong and taken too literally. What appears to be happening based on the math is a little more complicated. See this video for an explanation:

 

RJM Corbet

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Still, it's interesting to know that this effect of stealing energy from a black hole by splitting an object on the event horizon can be demonstrated in a laboratory with sound waves and a rotating disc?

I mean -- I dont know what I will do with the knowledge, but it's interesting to know, lol ...
 

Foxbat

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A Most helpful video. Thanks:
Still, it's interesting to know that this effect of stealing energy from a black hole by splitting an object on the event horizon can be demonstrated in a laboratory with sound waves and a rotating disc?

I mean -- I dont know what I will do with the knowledge, but it's interesting to know, lol ...
After watching the video explain fluctuating quantum fields I’m thinking the idea of using sound waves in the lab was pretty damn clever. Of course the people doing this must be pretty damn clever anyway :D
 

RJM Corbet

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A Most helpful video. Thanks:

After watching the video explain fluctuating quantum fields I’m thinking the idea of using sound waves in the lab was pretty damn clever. Of course the people doing this must be pretty damn clever anyway :D
Thanks @Foxbat for clever people:)
 
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