I think we have been overlooking this for years. Should the dimension of Time be relabeled the dimension of SpaceTime?
Having spatial mixed in with time allows gravitational waves and for light speed to be constant in time dilation volumes. It also allows for cosmic voids to expand. It satisfies the information paradox with black holes sending information to the 4th dimension. It also gives dark matter somewhere to live and be unobservable. It explains why we see gravity as weak ..the fabric of spacetime is 4D.
Only the force of a collapsing star and gravitational waves can interact with the 4th dimension. It doesn't change anything Minkowski discovered.
It answers how a particle gets observed and swapped from a wave to a particle.
The dimension of spacetime never wants quantum waves floating around in it. Or maybe I should say ..doesn't allow it if it knows it's there. It is a dimension of observation, I'm just saying it is what does the actual swapping.
There are three modes to a particle.Only quantum wave, duality, finished (collapsed). If the wave is not observed during its path, it will only be a wave in flight until it hits something. Duality has the quantum field and the dimension of spacetime fighting over it. Finished ..wave or particle hits a object too big to be influenced by the quantum field.
Spacetime grants a physical state when it is involved in any way during the path of a particle ..no quantum weirdness allowed.
The swap/mode change is done before the particle/wave starts to move. The entire timeline of the particle/wave is known before it starts moving. The Delayed choice quantum eraser shows us this.