# Tag Info

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Your question touches the question of ontology in particle physics. Historically we are used to be thinking of particles as tiny independent entities that behave according to some laws of motion. This stems from the atomistic theory of matter, which was developed some two thousand years ago from the starting point of what would happen if we could split ...

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Ill answer the second part of your question about effective mass and quasiparticles, since I see that CuriousOne has answered the rest better than I could have. In a metal or semiconductor, the electron is not in the same free state it would be in a vacuum. It is bound to (although delocalised within) a lattice of positive ions. So its dispersion ...

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The neutron is not a fundamental particle. It carries no electric charge, yet it can interact with photons as its components - the quarks - carry electric charge and thus couple to photons. Macroscopically/classical, these interactions cancel out since its net charge is zero, but quantumly, there is a very big difference between objects with charged ...

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HInt: Force on what? You need some charge to exert the force on. Otherwise you can calculate the electric field. To do that, you need to know the number of protons in $100$ g of normal matter. Since electrons don't weight anything and (at this level of approximation) there are the same number of neutrons and protons....

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The Rydberg electron - the electron in the high n level - is highly polarizable and very weakly held. The binding energy of the electron is very small. A small electric field will distort the wavefunction of the Rydberg electron so that it spends more time on one side of the atom than the other. The result is the formation of dipole. Rydberg electrons in ...

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A propagating EM wave is a field that needs no charges. Likewise, a propagating gravitational wave is a field that needs no masses. However in both cases there is no way (classically) to create the wave without a charge/mass. Considering EM, the divergence of the field is zero unless there is a charge, or put another way since field lines can only begin and ...

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I don't know cases in which the e.m. field can be produced without charges, however I can tell you how to produce an e.m. field without electric charges. Take a neutral particle, meet it with its antiparticle, have them clash, and you'll get gamma rays. The latter are electromagnetic. Also, gamma emission from excited nuclei, has not much to do with the ...

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Now per QED, electrical charges interactions are effected by photons. Suppose you are one of the two charges. How do you know to attract or repel the other charge? You want something that does not exist - intuitive picture of physical process within a theory which is a demonstration of how far can one go with mathematisation of experience and ignoring ...

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The original system as described in inherently unstable (or at best metastable). According to Earnshaw's Theorem, "a collection of point charges cannot be maintained in a stable stationary equilibrium configuration solely by the electrostatic interaction of the charges" http://en.wikipedia.org/wiki/Earnshaw's_theorem So the introduction of the slightest ...

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I don't think that quasineutrality is "a required condition", but is a property of most plasmas. Quasineutrality is the tendency for plasmas to attain electrical neutrality. It means that if a neutral plasma (with equal numbers of electrons and ions), should generate a region with a slight electrical charge, then because (a) the electric force is huge ...

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The frequencies are the same but they are 180 degrees out of phase with each other.

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In short: the laws of conservation (angular momentum, charge, mass-energy, etc.) still work during the process of creation of a black hole. So if a star had some angular momentum/charge before it collapsed, the resulting black hole will also have some (assuming the angular momentum/charge was not radiated away during the collapse). Also, the claim that ...

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Then does all charges, no matter how much charged are they, ionize the material around them since distance can get smaller and therefore electric field gets bigger. Consequently, the electric field exerted by the charge would be higher than the electrical breakdown limit of the material around it. Let's say you magically stick a (positive) charge inside a ...

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