I just recently learned that electromagnetic waves are made of oscillating electric and magnetic fields, and I have a question. In the standard model, photons are described as having zero charge, and if they are made from electric and magnetic fields, why are they not classified as charged? Is it because the crests and the troughs of the waves are canceling out? or is it more complicated than that?
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1Because theoretically you don't need to have a charge to create an electric field. – Gonenc May 15 '15 at 13:29
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- Why would electric and magnetic fields be classified as charged? Electric and magnetic fields classically just pass through each other (superposition prinicple of ED), they don't interact. 2. Look at e.g. this question for a QED reason why chargeless photon can still distinguish between charges.
– ACuriousMind May 15 '15 at 13:30
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Electric and magnetic fields themselves are totally uncharged. They are always described as totally uncharged things. They can either be described as two uncharged fields (when treated in the more traditional formulation) or as aspects of a unified electromagnetic field. In both descriptions the field(s) interact with charged things without being charged themselves.
The interaction works both ways so (for example) the electric field can move a charged thing around and the charged thing will cause a change in the field near it but the field itself is never charged.
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