Dear Readers,
I found evidence supporting my assertion, that low mass, self-propagating particles such as photons and electrons are not frequently manifested as localized particles, in wikipedia's 'Double-slit experiment' entry, 'Summary' section:
"The most baffling part of this experiment comes when only one photon at a time is fired at the barrier with both slits open. After many photons are emitted one at a time, and recorded on the same sheet of photographic film, the pattern of interference remains the same, even though each photon produces only a dot on the film. The clear implication is that for each photon, something with a wavelike nature passes simultaneously through both slits and interferes with itself so affecting the probability of its dot position.[14] (The experiment works with electrons, atoms, and even some molecules too [15].)"
ref. 14; ref. 15
I also highly recommend the section 'When observed emission by emission' which discusses how, when observed individually, emissions of 'electrons' produce single electron detections that, accumulated over time, produce an interference pattern as if they had propagated through both slits.
To account for these observational data, I suggest that emissions of quantum electron wave packets, while partially obstructed by a two slit screen, produce an extrusion of two independently directed wave fronts passing through the slits. The two independently directed waves interfere with each other: while only a single electron is detected for each quantum emission, in the two slit experiment it is detected at an apparently random location within an interference pattern that emerges following repeated individual quantum emissions.
Conversely, in individual quantum emissions through a single slit, electrons are detected in linear alignment with the slit - no interference pattern emerges because there is only a single wave passing through the slit.
That two waves emerge from a two slit grating, producing an interference pattern (even when only a single particle is detected), is evidence that propagating, non-localized elements dispersed through spacetime are only or most frequently manifested as waves, not particles. Non-propagating particles are detected when dispersed wave energy is collapsed to a single location. This seems to argue against the duality of elementary particle-wave states simultaneous coexisting in reality.
Sincerely,
Jim