On Sun, Oct 20, 2019 at 6:24 PM Bruce Kellett <[email protected]> wrote:
*> It seems that you think you will just see Young's interference fringes > whatever you do *after* the record is made at the screen. But that is > false,* > Like hell it is! Do you actually think Zeilinger and other experimental physicists claim they can make a photograph change before your eyes AFTER it has been taken like something out of Back To The Future? It was a fun movie but that's not the way things work. > > > as has been demonstrated in many experiments. > That statement is worse than false, you're talking logical nonsense. The photograph itself contains which way information, if the photo has no interference pattern then you know the photon went through one and only one slit, and if it does have a interference pattern then you know the photon went through both slits. So if you have the ability and really and truly want to destroy the which way information *AFTER* the photon hits the photographic plate (or screen) then you MUST destroy the photograph too and do so before anybody looks at it. In 1801 Thomas Young was not a fool and that's why he had no desire to destroy his screen *BEFORE *he looked at it, and that's why he saw a interference pattern; but it's true if he had he would have not seen a interference pattern, he would not see anything at all because there would be no screen to look at because he destroyed it. *> It does not matter whether you make the choice between which-way and > quantum erasure before or after the photons hit the screen.* > There is one difference and it's a rather large one. If you have no which way information at all (like Thomas Young) or if you make the erase/don't-erase decision *AFTER* the photon passes the slits but *BEFORE* it hits your photographic plate or screen or electronic detector (like Zeilinger and other experimentalists in the 21st century) then your experiment produces data; BUT if you really insist on erasing all the which way information *AFTER* the photon hits your photographic plate or screen or electronic detector then your experiment will produce NO data, not one bit of it, because you must destroy your photographic plate or screen or electronic detector. And you can't look at it before you destroy it because then you would have the which way information. *>That is what the experiments of Zeilinger and his associates show. These > are the experiments where the decision to erase or not were made 144 km > away from the lab in which the interference measurement was made.* > And why do you think the experimenters thought it was so important to make the distance between the slits and their detector that long? Because light is very fast and for practical reasons it takes time for experimenters to make the erase/don't-erase decision and it takes time to actually make the erasure, if the distance was as long as 144 km then even though light moves fast they still had enough time to do all that BEFORE the photons hit their interference measurement detector. >> If you place a polarizing filter oriented in the left-right direction >> over one slit and a polarizing filter oriented in the up-down direction >> over the other slit and shine a light through both slits and onto a screen >> you will not see a interference pattern on that screen because the filters >> have encoded information onto the photons about which slit they went >> through. However if you then place a third polarizing filter, this time >> oriented at a intermediate 45 degree angle, after the slits but *BEFORE* >> the screen then "the interference pattern emerges from the apparent >> no-interference" because that 45 degree filter has erased the which way >> information that was encoded on the photons *BEFORE* any photons hit the >> screen that you're looking at. >> > > *> That is not the experimental set-up of the Zeilinger et al. assessment > of delayed choice. Read the sources I have quoted.......* > Yes Bruce you have quoted sources, but I am not at all impressed. I do not believe for one nanosecond you understand anything in them and I doubt if you've spent more than 45 seconds skimming a Wikipedia article about them. John K Clark > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CAJPayv1Zkekkymmo8UaFXebTMwYGhtBVf0maHtgvMohHE_d43A%40mail.gmail.com.
