Virtual particle question
Posted: Wed May 18, 2011 1:09 am
Hello,Im doing research on virtual particles and was wondering if their are different views on virtual particles,Are they real or exist or are they not real?
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Quantum electrodynamics is our most accurate verified physical theory.outlaw wrote:
Hello,Im doing research on virtual particles and was wondering if their are different views on virtual particles,
Are they real or exist or are they not real?
I was reading that the casmir effect can be explained without virtual particles.neufer wrote:Quantum electrodynamics is our most accurate verified physical theory.outlaw wrote:
Hello,Im doing research on virtual particles and was wondering if their are different views on virtual particles,
Are they real or exist or are they not real?
Quantum electrodynamics is based upon the assumption of the temporary existence of virtual particles.
What more can I say?
Virtual particles were not conceived of after the fact in order to explain an already observed Casimir effect.outlaw wrote:
I was reading that the casmir effect can be explained without virtual particles.
neufer wrote:Virtual particles were not conceived of after the fact in order to explain an already observed Casimir effect.outlaw wrote:I was reading that the casmir effect can be explained without virtual particles.
[b]Casimir effect[/b] wrote:… Thus it can be interpreted without any reference to the zero-point energy (vacuum energy) or virtual particles of quantum fields.•
- Casimir effect and the quantum vacuum - RL Jaffe
- Physical Review D 72 020301 (July 2005) DOI: 10.1103/PhysRevD.72.021301
arXiv.org > hep-th > arXiv:hep-th/0503158 > 21 Mar 2005
Of course. Even physical things can travel faster than light, and do so commonly. Indeed, physical things can even travel faster than c under special cases where no information is transmitted at greater than c.outlaw wrote:I also read that a non thing can travel faster than light such as a shadow?
To be clear, it isn't traveling faster than light that is an issue, it is traveling faster than c. The two are not the same. Nothing that travels faster than c does so in a way that results in the transmission of information at faster than c, and therefore there is no backward time travel or problem with causality.outlaw wrote:I know that when something travels faster than light it has to deal with time travel backwards in the past and causality,do these things such as shadows travel into the past?
A shadow can transmit information and hence canNOT travel faster than c.Chris Peterson wrote:Of course. Even physical things can travel faster than light, and do so commonly. Indeed, physical things can even travel faster than c under special cases where no information is transmitted at greater than c.outlaw wrote:
I also read that a non thing can travel faster than light such as a shadow?
Yes, depending on how you define "shadow". But I think that the question is not really about shadows, but about certain non-physical projective phenomena (I believe we discussed the intersection of a closing scissors on this forum a few years ago), so I didn't want to get bogged down in the details of shadows specifically. (FWIW, a shadow carries information from the thing projecting the shadow, but it doesn't carry information from one surface it falls upon to another surface it fall upon at a later time.)neufer wrote:A shadow can transmit information and hence canNOT travel faster than c.
(A shadow travels at exactly the speed of light by definition.)