Delayed-choice double slit experiment

[zonde]

An actual delayed choice experiment with slits and polarizers is Walborn, et al, Phys Rev A 033818 (2002). A Google search will yield many other articles on actual experiments.

There are no changes in setup that are made on the fly as experiment is performed.

There is no faster than light communication here. The particles, i.e. the things moving through space-time, always travel at speeds less than the speed of light.

Yes there are no FTL in those experiments so I do not understand why you make statements that imply FTL.
If two places, one where we change the setup and the other place where photon is detected, are spatially separated and our change at one place can be observed as certain difference in observed results at other place without delay we could make Bell telephone.

The point is this: Bohr said we could wait until the very last minute to make a change. He was right! Modern delayed choice experiments confirm this.

And he means delay along the trajectory of photon. Not something like you imply with your statements.

I repeat for emphasis: If we change the apparatus at any time during the experiment, the results obtained correspond to the experimental configuration in place at the moment the experiment is closed, i.e. the instant when the particle is detected. We can wait until the last possible moment to make changes. It doesn't matter. Only the final experimental configuration matters.
Best wishes

I have a question - in what reference frame we should determine this "experimental configuration in place at the moment the experiment is closed"?
Because if we have made any changes to setup that are outside past and future light cones of detection event then this "configuration at the moment of detection" will depend from chosen reference frame.

 

[DrChinese]

Which points?

All spacetime points along every possible path (or history). So a lot of points contribute to the context!

 

[etamorphmagus]

All spacetime points along every possible path (or history). So a lot of points contribute to the context!

Sure, but what points are the critical ones? You leave a lot of room for questions with your answers, sorry if this is frustrating for you.

And what do you mean by context?

 

[DrChinese]

Sure, but what points are the critical ones? You leave a lot of room for questions with your answers, sorry if this is frustrating for you.

And what do you mean by context?

All would conceptually be equally relevant in a sense. But you could consider the end point of each possible path as making a "more relevant" contribution. (Although you can't exactly it an end point in the strictest sense.)

It may be easiest to picture the context from the position of the source, and look into the future. What could you "see" if you could look towards the future?