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Having Radiation and Virtual Particles

Anonymous Mon 22 Feb 18:23:34 2021 No.12741976 View Reply Original Report

Quoted By: >>12743068 >>12743211 >>12743490

Is it potentially valid to describe quantum tunneling as the simultaneous creation of two opposing particles out of the quantum foam followed shortly by one of those particles anihilating with the wrong particle some distance away?

I'm finding it hard to conceptualize how virtual particles lead to Hawking radiation without the aforementioned description. I mean, if one photon pops in on one side of the event horizon and the other on the other side then how does that lead to the black hole losing mass unless the photon within the black hole is cancelling out some mass-energy on the inside?

Anonymous

Anonymous Mon 22 Feb 2021 22:08:54 No.12743068 Report

Quoted By: >>12743385 >>12743490

>>12741976
You're having a hard time conceptualizing because you have absolutely no fucking clue what you're talking about. Tunneling arises as a result of solving the Schrodinger equation over a potential with classically forbidden regions (i.e. the energy is lower than the potential in that region). This is something that you get from solving any kind of linear second order PDE. The solution (the wavefunction) has to be continuous and differentiable everywhere (unless it is a singular potential), which means it can't just abruptly end at a barrier. Tunneling is a very "typical" behavior that one can observe without exotic shit like quantum gravity or even relativistic quantum mechanics.
Hawking radiation on the other hand is a phenomenon specific to quantum gravity and has to do with all kinds of complicated shit like black hole thermodynamics, general relativity, quantum field theory, etc. Trying to explain it with quantum tunneling is oversimplifying the shit out of it.
tl;dr don't delve into topics you have absolutely no qualifications in
t. theoretical HEP grad student

Anonymous

Anonymous Mon 22 Feb 2021 22:45:46 No.12743211 Report

Quoted By: >>12743385

>>12741976
Short answer: No

Slightly longer answer: The pop-sci explanation of concepts like tunneling, virtual particles and Hawking radiation are always missing important details. This can be a bit of a hazard as it's easy to think that you know what something means when you don't actually even know how it's defined. This is why what you have written in the OP just looks like word salad.

Anonymous

Anonymous Mon 22 Feb 2021 23:44:47 No.12743385 Report

Quoted By: >>12743419 >>12745249

>>12743068
>>12743211
So how do virtual particles have anything to do with Hawking radiation? I'm assuming the explanations I've read are not outright lies, even if they may be misleading. I therefore assume virtual particles have SOMETHING to do with Hawking radiation, I just can't reconcile that alleged relation with my distinct understandings of each.

>tl;dr don't delve into topics you have absolutely no qualifications in
Though I empathise with you, I whole heartedly disagree. I believe learning is inately valuable. The problem you may have with one asking questions about topics that one does not have a deep understanding of is that it may lead to a foolish confidence in educational shortcuts and shorthand. I don't have that foolish confidence, though I DO grudgingly accept shortcuts to understanding more about the things I'm curious about.

Anonymous

Anonymous Mon 22 Feb 2021 23:54:13 No.12743419 Report

Quoted By:

>>12743385
>So how do virtual particles have anything to do with Hawking radiation?
They do. I said tunneling has nothing to do with it, it's an entirely different phenomenon. You don't even need particles as a concept for tunneling to exist.
>I believe learning is inately valuable
so pick up a book on quantum mechanics instead of reading pop-sci junk. I can suggest McIntyre. If your math is rusty, be sure to also read something on linear algebra and calculus, although McIntyre treats the reader as a somewhat of a newbie to those. If you manage to go through that (it's a good book for a complete beginner), you still have a loooong way to go before you can begin to understand what stuff goes on in Hawking radiation. You need to be proficient in general relativity, statistical mechanics, quantum field theory, and then you need to somehow learn a combination of these three. Most physics grad students don't do that, only some autistic theorists. This stuff is very mathematical in nature and describing it with these hand wavy terms you see in pop-sci doesn't do it justice.

Anonymous

Anonymous Tue 23 Feb 2021 00:14:07 No.12743490 Report

Quoted By: >>12743534

>>12741976
What tunnelling is talking about, in simplest terms, is the idea that a wavefunction is technically not confined to any finite region of space (or momentum). We think of the wavefunction as roughly representing the "smearing out" of a particle's location and other continuous qualities. The particle cannot really be said to have a definite location (in almost all interpretations of quantum mechanics) or momentum or energy. Because the wavefunction isn't localised to a finite region like a particle is, this represents the fact that there is a very small chance that the particle may be found somewhere which it would not be found if only classical laws were followed.
For example, if you were trapped in a closed room without a roof, classically speaking, you could not get out unless you had enough energy in you to leap out over the top. In other words, you've got to have at least enough energy to match whatever potential energy you'd need to gain at the top of your jump to get out of your enclosure.
But if we had electrons in a potential well, there is an uncertainty in how much energy the electrons have, so we might find that for a short time, one electron has actually taken a larger share of the energy, and the other electrons have less. That can be enough to let one electron escape the potential well, while the electrons that didn't get out have less energy than normal. After some time the energy will have returned to a more reasonable distribution (we say the energy is "paid back" later, but the idea of "borrowing" the energy is just an analogy).
>>12743068
>tl;dr don't delve into topics you have absolutely no qualifications in
This is like shouting TRUST THE EXPERTS and treating science like a religion

Anonymous

Anonymous Tue 23 Feb 2021 00:29:07 No.12743534 Report

Quoted By: >>12743836 >>12744046

>>12743490
I didn't say he should "Trust the experts". I said he shouldn't talk about stuff he doesn't understand pretending like he does. Being sceptical and ignorant are two different things.

Anonymous

Anonymous Tue 23 Feb 2021 01:51:25 No.12743836 Report

Quoted By:

>>12743534
alright, maybe
>don't delve into
was just badly phrased

Anonymous

Anonymous Tue 23 Feb 2021 02:58:34 No.12744046 Report

Quoted By:

>>12743534
>pretending like he does
Who's pretending?

Anonymous

Anonymous Tue 23 Feb 2021 11:25:26 No.12745249 Report

Quoted By:

>>12743385
Virtual particles are terms in a perturbation expansion, they are a part of a mathematical tool-set and show up wherever you use a certain type of math to describe your problem. You don't have to use them, you can describe Hawking radiation without them, but using them makes for convenient math.

You can use virtual particles in an approximate calculation of tunneling and the two concepts are sort of connected in that way, but you don't have to do it in that way.

I don't blame you for having a hard time with this, what you should understand is that most of the stuff you read about virtual particles that does not involve the mathematical description is downright wrong by the very way virtual particles are defined (the wikipedia article especially is a good example of why wikipedia should not be trusted on all topics), even some physicists get confused.

People get confused by this, especially in astrophycis and particle physics, because a few pop-sci physicists get all philosophical and start talking about virtual particles in a very sloppy way (you rarely see the same confusion in condensed matter even though the same description is used). For all practical purposes virtual particles are a mathematical tool, an artifact of the way calculations are done.

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