Double Slit Experiment: Is Observation Equipment Interfering?

[DrChinese]

Good example,
it shows the overlapping dispersion patterns I described,
and how the inerferance pattern only appears in the area of overlap.
And NOT the two bar result you described

I guess my definition of two bars is different, but that is what it is often called. I did not mean to imply it was a literal bar, just that there are no interference fringes. If you use 3 slits, you get 3 bars, 4 slits leads to 4 bars, etc.; as long as you know which slit it passes through, the extra "bars/fringes" don't appear.

I think JesseM covered the entangled version pretty well. It is clear from that reference that a single dispersion pattern (I call it a wide bar) results when all of the photons are considered. The "interference" pattern is only present when coincidence counting, i.e. when a select subset is examined.

When you think about it, it is odd that photons act differently going through a double slit depending on whether they are/were entangled or not. But they must, in order to match the requirements of the HUP (and no FTL signaling).

 

[RandallB]

I guess my definition of two bars is different, but that is what it is often called. I did not mean to imply it was a literal bar, just that there are no interference fringes. If you use 3 slits, you get 3 bars, 4 slits leads to 4 bars, etc.; as long as you know which slit it passes through, the extra "bars/fringes" don't appear.

I think JesseM covered the entangled version pretty well. It is clear from that reference that a single dispersion pattern (I call it a wide bar) results when all of the photons are considered. The "interference" pattern is only present when coincidence counting, i.e. when a select subset is examined.

When you think about it, it is odd that photons act differently going through a double slit depending on whether they are/were entangled or not. But they must, in order to match the requirements of the HUP (and no FTL signaling).

Remember you have novices on these forums.
Understanding the double slit requires thin slits that produce dispersion NOT BARS is important and bars is misleading – the term Bars hurts rather than helps a new reader on the topic.

Even the good example you linked to is “extreme” as the two “peaks” you want to represent as “Bars” are never actually seen in real DS experiments.
The real overlap is much more complete in real experiments.


As far as the detecting entanglement as existing by only using a Double Slit without a working counter that debate should return to the other thread.

I’ve yet to see Jesse or anyone provide or site results from such a simple to run experiment that shows me wrong, Just near field hand waving arguments and I apply the DNFTT rule to that nonsense.

And as to HUP; how does it not not use equation (7) in the experiment you sited there.
Did you even re-read what I suggested you review there?

 

[JesseM]

I’ve yet to see Jesse or anyone provide or site results from such a simple to run experiment that shows me wrong, Just near field hand waving arguments and I apply the DNFTT rule to that nonsense.

The experiments I and bruce2g linked to describe cases where there is no interference in the total pattern of photons but there is interference in the coincidence count, with the same experimental setup--this is just like the situation with the quantum eraser where you claimed that since there's interference in the coincidence count when no filters are present, you expect there must be interference in the total pattern of entangled photons. Everyone who knows something about QM on this board has told you are wrong about this, on multiple threads, and you never provide any actual evidence for your claims in terms of experts who agree with you or detailed calculations; now apparently you're not even going to respond to my points and just accuse me of trolling, so since you're making wrong claims about physics and refusing to discuss them rationally, I'll go ahead and report your posts on this subject to the mods if you continue to behave this way.

 

[mauripelto]

Is anyone out there trying to reproduce Young's double slit experiment by detecting single photons, as in scanning the interference pattern and then measuring the total flux of photons in the apparatus during the experiment?

Mauri