Hi, thanks for reply.
Quoting: "towards a plane that consists of two holes": my point is that there is no such thing as a "plane" at one time. Look at a large wall, standing opposite the wall-center.
The distances to you are longer from the wall corners and from any places away from the point on the wall directly opposite to you; than the distance to you of the point opposite to you.
So when you stop your clock; you are seeing NOT a plane from a time-point of view; you are seeing a hemisphere. If you call it a plane then you have "now" in the center of that plane, and out from the center you have light from the past.
So when you treat the two holes as being in a physical plane in the everyday "all now" sense; this is not a complete enough account of the scene. The so-called plane is, due to the slowness of light, a curved time-surface and it is no problem for light to travel sequentially through the slits as the slits are plainly (pun!) AT DIFFERENT TIMES whenever they are regarded as being in a plane in the everyday sense.
Roger Penrose considered the possibility of a geometry that allowed a superposition of the slits sequentially but apparantly missed this simple solution!
A "photon" is aparantly a "path"; of course "paths" appear to interfere. Michael raised a significant issue re: "choice of choices collapses to a single choice". He was right to object to what I wrote. Facing this issue allows insight into a quantum puzzle (possibly page 292) discussed in Roger Penrose's "Shadows Of The Mind".
It involves a bomb-testing problem, where not detecting a photon tells you something.
Suppose I walk into a shop and want to explore it.
Consider two paths: path 1: I decide to explore a quarter of the shop (1 choice).
path 2: I decide to explore half the shop (1 choice), then immediately decide to explore half of (2nd choice) that half.
These two paths are different. The 2-choice path may look like the same outcome as the "explore a quarter of the shop" path; but it is different.
The second path had more structure.
Have to go back to the book and get back to you with the solution I figured out.
I recognise the view that time does not pass for photons, and wondered if there were problems with my angle on the puzzle. However, the speed of light is only constant because it is a constant ratio between two unknowns.
Speed is just distance per time; and "time" values are demonstrably distance values; so "speed" is self-referent distance (distance per reference distance, like miles per fraction-of-a-mile-that-caesium-vibrates).
The speed of light is measured by gadgets using light; so is just a mirror effect- the mirror is constant.