Shouldn't force carrier particles not propagate at "c"?

[questionposter]

As per the other thread about FTL...

From http://en.wikipedia....antum_mechanics:

"In quantum mechanics, virtual particles may travel faster than light, and this phenomenon is related to the fact that static field effects (which are mediated by virtual particles in quantum terms) may travel faster than light (see section on static fields above). However, macroscopically these fluctuations average out, so that photons do travel in straight lines over long (i.e., non-quantum) distances, and they do travel at the speed of light on average. Therefore, this does not imply the possibility of superluminal information transmission."

 

I don't see how information isn't transferred superluminally if a virtual particle emitted by a parent particle can interact with a target particle in a shorter amount of time than light could. Also, just how much faster can virtual particles travel? It also lacks a citation...

Perhaps virtual photons are just so delocalized that it's possible for them to "pop up" in a region ahead of where localized light would be, but every virtual particle would seem to have to have an analogous delocalization equivalent in size to that of the of the static field in order to instantaneously react with any object already present in the field, and I don't know if they do...

Edited April 21, 2012 by questionposter

[md65536]

I don't see how information isn't transferred superluminally if a virtual particle emitted by a parent particle can interact with a target particle in a shorter amount of time than light could. Also, just how much faster can virtual particles travel? It also lacks a citation...

Perhaps virtual photons are just so delocalized that it's possible for them to "pop up" in a region ahead of where localized light would be, but every virtual particle would seem to have to have an analogous delocalization equivalent in size to that of the of the static field in order to instantaneously react with any object already present in the field, and I don't know if they do...

 

I don't think you can measure individual virtual particles? ("If a single particle is detected, then the consequences of its existence are prolonged to such a degree that it cannot be virtual."[1])

I don't think you can transfer information at all with them (As individual particles. "only their average or side-effects may be noticed"[1]).

Virtual particles are different in behavior in some ways from "regular" particles. I don't think the same notion of "interaction" (as with information transfer) applies...

 

I think a good understanding (which I lack) of some Feynman diagrams with all the weird and backwards paths that are possible, would answer your questions.

 

 

 

References:

1. http://en.wikipedia.org/wiki/Virtual_particle

Edited April 21, 2012 by md65536

[questionposter]

I don't think you can measure virtual particles?

I don't think you can transfer information at all with them.

Virtual particles are different in behavior from "regular" particles. I don't think the same notion of "interaction" applies...

 

I think a good understanding (which I lack) of some Feynman diagrams with all the weird and backwards paths that are possible, would answer your questions.

 

 

 

I guess maybe with time symmetry they somehow interact with a particle before being emitted or something like that, but the more I think about it, the more a delocalization theory makes sense especially considering if they had very low relative energies, but that would also have to mean that gravity would technically change faster than light by the same mechanisms, though I suppose it doesn't actually break relativity.

[md65536]

I guess maybe with time symmetry they somehow interact with a particle before being emitted or something like that, but the more I think about it, the more a delocalization theory makes sense especially considering if they had very low relative energies, but that would also have to mean that gravity would technically change faster than light by the same mechanisms, though I suppose it doesn't actually break relativity.

Yes but again I don't think the interaction is of a type that could transfer information.

Changes in gravity could theoretically be used to transmit information and can't propagate faster than c according to relativity.

 

Hypothetical "real" gravitons would be restricted by c. Hypothetical virtual gravitons wouldn't. A static field wouldn't be able to transfer information (only a changing field could).

 

I think.

 

Anyway, I don't know much, but I think it's best to not get hung up on thinking about virtual particles as if they're physical things. Perhaps they're the effects of some physical thing that we haven't quite worked out all the details of, or perhaps they're just an abstraction---a tool for calculation---whose behavior makes the most sense described as a "particle" as far as what we know about. If they're "real things", they're not so for long enough to imagine them doing any real in the world.