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If we got an oscilating electron up and down, it will definately produce changing electric field. I won't go into magnetic field topic. Let's only restrict the question to electric field.

Since we got a changing electric field, we know that it produces sin or cos wave. My question relates to how it produces the sin or cos wave. The reason I have doubts is the way charge A produces a field for charge B is A sends virtual photons to B. at t=1, A sent off photons. at t=1.1, it again sent off photons from new position. The key is: "new position". but if you look at the sin wave of changing electric field, at some t values, the graph shows 0 for E field magnitude. Definately, it shouldn't be 0. I might be asking it in a wrong way, but I will update the question if something is not clear.

Matt
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I think your question mixes the classical view of electromagnetism (electric field, etc.), with quantum field theory (virtual photons, etc.).

If you want to know why an accelerating electron moving back and forth generates a moving wave, the answer is best understood from classical electromagnetism, and by the way, involves the magnetic field which you tried to ignore - the accelerating electron generates a magnetic field, a changing magnetic field, which in turn generates a changing electric field which generates a changing magnetic field which... ends up a moving wave in both electric and magnetic fields - this is the electromagnetic wave. You can find a gazillion books and online resource on this topic, a random one I found in Google is: http://labman.phys.utk.edu/phys222core/modules/m6/production_of_em_waves.html

But the question asks how virtual photons, which is the realm of quantum field theory. I guess it hinges on why in the classical limit (high enough intensity - many photons, not just one), you can measure a zero of the the electric field. This zero doesn't come from a single virtual photon, but from the superposition of many virtual photons. I'm not familiar enough with the theory to give a good answer, but it has been asked here before - e.g., see Virtual photon description of $B$ and $E$ fields

Nadav Har'El
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