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Rational_One

Virtual Particles

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Near they end of Section 8 of Little's paper on TEw Little states "Weingard's arguments against the interpretation of internal propragators as corresponding to real particles is no longer applicable. ...they actually correspond to both wves and particles." Should one take this to mean that the theory rejects the existence of "virtual" particles?

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Near they end of Section 8 of Little's paper on TEw Little states "Weingard's arguments against the interpretation of internal propragators as corresponding to real particles is no longer applicable. ...they actually correspond to both wves and particles." Should one take this to mean that the theory rejects the existence of "virtual" particles?

Speaking first as a moderator, I ask that you pay more careful attention to what you write. There are two spelling errors in your quote of Dr. Little, and those errors were certainly not present in his original writing. In addition, you have changed a couple of words from the original quote. In general, it is important to pay attention to spelling and grammar, but especially important when quoting someone else. The correct quote is:

"Because it is only the waves that take all paths, and not the particle, Weingard's arguments[19] against the interpretation of internal propagators as corresponding to real particles are no longer applicable. Actually, the propagators correspond to both waves and particles."

Now, speaking as myself, in the standard theory, in quantum field theory, a virtual particle is a mathematical abstraction -- terms in a perturbation series -- required to make Feynman diagrams work. The emission and absorption of intermediate particles is the process by which particle interactions are considered. These intermediate particles are not observed, hence the name virtual particles. It is usually thought that these virtual particles can violate conservation laws (such as energy or momentum), but quantum field theory actually develops the concept of an off-mass-shell which saves virtual particles from lack of conservation. Feynman diagrams are supposed to be pictorial representations of such particle interactions. (Note that in some form of field theory the virtual particles disappear entirely.)

The TEW gives a causal explanation for the physical phenomena captured by the mathematical formulations. Likewise, the TEW recognizes that Feynman diagrams can be interpreted in a way in which they pictorially represent real physical processes, and in Little's 1996 paper he illustrates both the mathematics and the physics principles involved. In the TEW the Feynman diagrams actually capture the physics involved, and to that extent virtual particles have a real existence, along with their elementary waves.

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Sorry for the misquote.

What you discribed is what I picked up from the theory that the virtual particles are actually real particles in TEW.

As a follow-up question then how does TEW explain Hawking radiation of a black hole? I have an idea in my head but would like to possibly have an expert explanation so that I don't embarass myself if I'm wrong.

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As a follow-up question then how does TEW explain Hawking radiation of a black hole?

What makes you think that Hawking radiation needs to be explained? If we spent our time "explaining" the speculation of others, we may not have enough time left for physics.

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What makes you think that Hawking radiation needs to be explained? If we spent our time "explaining" the speculation of others, we may not have enough time left for physics.

So then... I'll take it TEW simply rejects it. :o

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So then... I'll take it TEW simply rejects it. :o

I was speaking for myself, not the TEW. [*] I do not ever recall discussing Hawking radiation with Lewis Little, but I suspect he would agree that it is pure speculation, based on mathematics, not physics or observation. It is not so much rejecting it, as needing more than speculation for serious consideration.

[*]When I speak on THE FORUM of the TEW, I am doing so with my best understanding of the theory, not as an official spokesperson. Lewis Little is the only official spokesperson for the TEW. I am, however, a staunch advocate of the theory, and have spent considerable time studying it in depth.

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I am, however, a staunch advocate of the theory, and have spent considerable time studying it in depth.

Which is why my quetions are essentially aimed at you. I really like the theory but I have to integrate it with the physics I already know and with recent discoveries. I can't just accept it on faith. And I appreciate your answers so far but I thought Hawking radiation of black holes was pretty well accepted. This leads me to another question, being that TEW in principle accepts General Relativity, I'm assuming it accepts the existence of black holes. There seems to be great evidence that they lie at the center of most if not all galaxies. If the TEW accepts the existence of black holes why would it not except a theory explaining their slow evaporation? I'm really just trying to figure out why you consider this to be arbitrary. Is it because we don't have first hand evidence, yet, of this evaporation or is there another reason? Please note, I'm not so much defending Hawking radiation here as I'm simply trying to understand your responce.

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And I appreciate your answers so far but I thought Hawking radiation of black holes was pretty well accepted.

General acceptance is not a criteria for existence. If it were, we would all be in church on Sunday.

This leads me to another question, being that TEW in principle accepts General Relativity, I'm assuming it accepts the existence of black holes.

Not all mathematical solutions to equations correspond to existents in reality. Black holes are a solution to the Einstein field equations, and all such realistic solutions have a central singularity as an essential feature of the solution. There is nothing wrong with mathematical singularities, per se, but physical singularities do not and cannot exist. One does not even need to be a physicist for this realization; philosophy alone tells us as much.

Now, you indicate that there is "great evidence" for black holes that lie at the center of galaxies. To this I would say that there has been increasing evidence that can be interpreted for the existence of some object, but whatever that object is, it cannot be a black hole as described by general relativity. Even if one accepts the interpretation of evidence for there being a central object in galaxies, there are several possible alternatives to black holes. One relatively recent hypothesis is that of a gravastar, a new solution to Einstein's field equations. This gravastar has a very small, but nevertheless finite thickness of ultracold matter with ultra-relativistic energies, all of this surrounding an interior region which has certain quantum properties similar to what you may have heard referred to as a Bose-Einstein condensate.

This gravastar solution does remove both the horizon and the central singularity, which is a bare-bones criteria for serious consideration. The solution, however, is a static one, and work needs to be done for a dynamic solution. But, regardless, whether the answer is a gravastar, or some as yet not conceived entity, the black hole with its central singularity is both philosophically and scientifically unsound.

But, permit me to underscore the most important point -- if you take just one point away with you from this discussion -- and that is, to reiterate, not all mathematical solutions correspond to physical existents. We look to reality, not mathematics, as confirmation of that which exists.

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Is a gravastar similar to a quark star? A few years ago I had a professor of mine who specializes in CP violation and QCD get all excited and tell me about the possible discovery of one. But I have really kept up on it since.

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But I have really kept up on it since.

This sentence should read: But I have NOT really kept up on it since.

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Is a gravastar similar to a quark star? A few years ago I had a professor of mine who specializes in CP violation and QCD get all excited and tell me about the possible discovery of one. But I have really kept up on it since.

They are different. Your professor undoubtedly was referring to a controversial paper almost three years ago in which the authors presented some evidence to bring into question a star that was previously thought to be an isolated neutron star. They offered further evidence that the X-ray observations were consistent with quark matter equations of state. See Is RX J185635-375 a Quark Star?, J.J. Drake, et al., Astrophys. J., V. 572, pp. 996-1001, 2002.

The idea for a quark star has been around for about two decades. Ed Witten himself had some speculations in the early 1980s. The process involves the conversion of light quarks to strange quarks, which is why sometimes one hears the term 'strange star' rather than 'quark star'. I believe the EOS for such a star was first found and investigated almost a dozen years ago. See Equation of state of strange quark matter and strange star, S. Chakrabarty, Physical Review D, V. 43, pp. 627-630, 15 January 1991.

The gravastar is much more recent notion.

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