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Virtual particles never been considered "real" in any serious interpretation of QFT for two reasons: 1) what we call virtual particles are just terms in a series at some order of a coupling constant, 2) there's no way to interact with them. An interaction between two physical objects is a black box in QFT. The way people usually use to "see" inside this ...


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1) There exists the classical electromagnetic wave as described by Maxwell's equations. 2) The photoelectric effect showed that these electromagnetic waves are composed of photons, with energy E=h*nu , where nu is the frequency of the classical wave. Single photon experiments have been performed by limiting the intensity of the beam to one photon at the ...


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The interaction between two charged partices occurs through a change of momentum. All very well, but the next question is how we calculate the momentum exchange, and this is where quantum field theory comes in. The interaction between two electrons is described as a disturbance in the quantum fields involved. Quantum field theory gives us an expression for ...


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The Lamb shift According to the hydrogen Shrodinger equation solution, the energy levels of the hydrogen electron should depend only on the principal quantum number n. In 1951, Willis Lamb discovered that this was not so - that the 2p(1/2) state is slightly lower than the 2s(1/2) state resulting in a slight shift of the corresponding spectral line (the ...


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Virtual particles are far more plausible because of experimental results such as the Casimir Effect which is non classical and predicted as a consequence of the "reality" of virtual particles.


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It appears the main confusion here lies in the concept of a particle. So to simplify things, first consider flat space-time which is sufficient to discuss most of the issues here. An accelerating observer in flat space-time will see an event horizon of a finite temperature, emitting particles. This is called Unruh radiation. This is purely a coordinate ...


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from The Reference Frame: Another wrong expectation that a beginner could have - and usually has - is that if you allow the summation over all trajectories of a particle, the typical particles will move faster than light most of the time and this will automatically result in a violation of the special theory of relativity. So an overzealous ...



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