On Fri, Oct 18, 2019 at 10:05 AM 'Brent Meeker' via Everything List < [email protected]> wrote:
> > But I wonder what happens in Carroll's experiment if, after measuring in > the left/right basis and noting that two different interference patterns > can then be discerned by considering either those due to left spin > recording particles or considering right spin particles, one measures the > recording particles again in the up/down basis. The overall pattern is the > same, it's just that you've relabeled spots on the screen according to > whether the second measurement of recording particles assigned them to UP > or to DOWN. Now you can consider the subset labeled UP (or DOWN). This > should be a superposition of ensembles randomly selected from the left and > right ensembles and in that case would not show an interference > pattern...but the information has certainly been erased (twice)? > If I understand you, what you are suggesting is that either the left polarized, or right polarized, are measured again in the up-down direction. I think that if you do this second measurement, you will simply reduce the intensity by a factor of two. The welcher weg information was permanently erased by the first left-right measurement. Bruce -- 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/CAFxXSLSFBb%2BUdFEdA1EYHFL0pD0WGg9JV75siakQxFroah6Uog%40mail.gmail.com.
