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  1. H

    One dimensional Coulomb potential

    You have to solve the exact equation. Finally, applying the boundary condition X(0) = 0 (because of the unfinite potential step) should deliver the discrete spectrum of solutions.
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    Photon and anti-photon annihilation?

    The experiment is about a scattering process with REAL photons (originating from laser sources). Of course, these photons have positive energies (frequencies).
  3. H

    Photon and anti-photon annihilation?

    I think that this process has in fact been observed - even for real photons: Positron production in multiphoton light-by-light scattering
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    Relativistic quantum mechanics and causality

    Are you sure ? Afaik, the propagator of a massless particle has a pole on the lightcone, but summing up the contributions due to internal lines in a diagram (by integration over 4-momenta), there are also contributions from propagators connecting events with timelike or even spacelike distance...
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    Virtual particles

    The fundamental difference between real and virtual particles is that virtual particles do not have to be on their mass shell, i.e. they do not fulfill the fundamental energy-momentum-mass relation of Special Relativity...
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    QED: the strange theory of light and matter. Light is made of particles ?

    Thanks, Cthugha - something to think about. :)
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    QED: the strange theory of light and matter. Light is made of particles ?

    The confusing thing (at least to me) is that we have to associate a fixed frequency to the photon: E = h * f This is the energy quantization of electromagnetic waves found by Einstein in the Photo-Effect: the energy transported by an electromagnetic wave of frequency f is always a multiple of...
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    The cause of entanglement / coupling

    But the discussion there relates to magnetic moments: entanglement is a far more general effect, which concerns electrically neutral components as well (for instance photons). I don't see so much similarity between quantum entanglement and couplings by physical interactions. Nevertheless...
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    The cause of entanglement / coupling

    I wonder what do you want to indicate by the phrase "purely mathematical property" ? Entanglement is physics: it is the nonlocal character of quantum mechanics.
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    The cause of entanglement / coupling

    Hi, I wouldn't say so, I think that these are very different "mechanisms": coupling is the consequence of an interaction. Think for instance of coupled harmonical oscillators. Entanglement, on the other hand, ist not based on an interaction. The "classical" example is indeed a system of 2...
  11. H

    Why energy level transitions only absorb or emit photons?

    A transition from one energy level to another one must prevail the nature of the atom. Emission of an electron for instance would create a charged object instead of an atom; this process is called ionization.