text: Let a source emit a photon at A and it arrive at B where a detector registers it. The particle model states that the photon is emitted at and absorbed at B. No need to re-emit. And this holds for distances from 1 nm to any number of light years.
  Its not possible to state whether a photon is a particle or a wave unless you state how its observed. That's the essence of the wave-particle duality.
  Note that the Schrodinger equation only holds for non-relativistic particles and photons are relativistic particles.
  What is a "sub elementary particle"? There's no such thing that I'm aware of. In any case there's no basis to assert that they're in the ground state. That's only possible when a particle is in a potential. And spacetime has little to do with explaining this.
  Unlike Maxwell, the particle model doesn't predict the speed of light, nor that it is constant for all photons, unless you accept the conclusion of general relativity, i.e. that massless particles must all travel at c. Problem there is that this is an experimental result that is axiomatic to the GR model, not a prediction of the model. Nor is it terribly good at propagating radio waves. Admittedly it all hangs together in the end, but I don't think GR requires quantisation, nor vice versa.
  Consider the double slit experiment, with just one particle at a time. If whatever-it-is passes through both slits simultaneously (i.e. a wave), then its energy, mass and charge must be distributed simultaneously across the detector according to the observed diffraction pattern. But nobody has observed a particle with a fractional charge, mass, or increased photon wavelength at any point. What actually happens is that single photons, electrons or entire buckyballs ping into the detector at various positions and the integral of their distribution over umpteen particles looks like a classical interference pattern.
  At the time of reaching the slit, our projectile has no way of knowing how or even whether it is going to be detected, so the implications of "duality" don't make sense.
  Understood, I was trying to visualize or get a mental picture that covered both scenarios of a photon, from a quantum perspective. Wave Particle duality sounds like Schrodingers cat, which might be dead or alive, unless maybe you don't feed it .
  Relativistic versions of the Schrodinger equation exist, ie the Klein Gordon equation. https://en.wikipedia.org/wiki/Klein–Gordon_equation and there is relativistic quantum mechanics https://en.wikipedia.org/wiki/Relativistic_quantum_mechanics neither of which give any support to what I was trying to visualize as far as I can see.
  Not knowing exactly which slit might make it probable 50 50 which slit. However the interference pattern suggests if it is a particle it didn't go in a straight line. Which is where I got stuck in a loop, with absorption and emission
  Photons are localized lumps of energy, wave packets with a reasonably well-defined position and momentum, with an uncertainty consistent with atandard quantum mechanics. Like waves, photons can be very delocalized. Each photon in a laser beam has the same shape as the classical field by which this beam is described.
  In a double-slit experiment with visible light the distance between two slits can be macroscopic, e.g. 0.1 millimeter, or something like that. In order to get an interference pattern, the photon lump should be no smaller than this size. The corresponding volume is filled with a time-changing electromagnetic field, the light beam. This macroscopically large (but in a weak beam possibly very faint) lump of electromagnetic energy falls on the double slit and interferes with itself according to Maxwell equations - its shape becomes that of a superposition of two spherical waves and becomes even more delocalized over a quickly growing region. Then this big but distributed lump of energy reaches the photographic plate and blackens a single silver grain. The photon energy that was previously spread up in a macroscopic region now gets released within a group of few atoms.
  If the field around photons is reacting with the double slits as it approaches would this negate the need for wave particle duality?
  Wouldn't it also be represented as a field which interacts with the slits before going through one of them?
  I expect the same experiment can equally be performed by firing a single buckey ball in multiple separate locations, and when the results are brought together the wave pattern still exists. Clearly the buckey balls or photons in separate labs will have had no wave interference from the other labs.
  The wave interaction is theorized to exist after multiple particles go through one or the other slit producing the waves
  With QED the interaction is before the particle goes through the slits and doesnt require wave particle duality, which is hard to visualize, and not very appealing when there is a simpler way of viewing photons and particles.
  Does De Broglie Bohm / Bohemian mechanics give a valid explanation of a photon in your opinion ? A field surrounded by a pilot wave. It is deterministic, and relativistic versions exist.