If I set up an interference experiment and make one path much longer than the other would I still see an interference pattern? If so why? It would seem to me that having one path very long would give which-way information because you could easily time the photons to see which path it went...
Way off topic here, but there are two other interesting possibilities for storing photons/energy.
1. Slow Glass - a method of slowing photons down as they move through a material.
http://focus.aps.org/story/v17/st1
2. An optical black hole.
http://www.cerncourier.com/main/article/40/4/10
JesseM:
I guess I was wrong. I wonder if Feynman had this much trouble keeping it all straight? And I only capitulate because the experiments seem to say what your saying. But I still don't understand why.
I mean, if only about 200 photons a second are actually entangled then why would the...
I agree. You would see an interference pattern.
If you just viewed a screen behind the double slit you would "see" an interference pattern. Of course, the way I understand it you are viewing much more than just entangled photons. PDC (parametric down conversion) only produces a few hundred...