Saibal Mitra fwded > It may be a question of "interpretations of interpretations of QM", > however on the basis of the New Scientist article, I don't believe > Afshar have shown a problem with the complementarity principle.
I agree. But imagine the usual two-slit set-up. And this unusual screen, to reveal the interference pattern ... _________ _________ _________ _________ _________ _________ They are a set of photographic plates, they can register both the photons and their directions, i.e. if they come from the upper or from the lower slit (photons coming from the upper slit hit the upper face of the photographic plate, photons coming from the lower slit hit the lower face, there is a principle of conservation of momentum after all). Calculations made by Zurek and Wooters show that this kind of screen works, that is it can reveal - in principle - both the "welcher weg" and the interference pattern. But the complementarity principle forbids that. > *PS: A number of people ask me about the attachment to my email, which > is of type "application/pgp-signature". The problem with that signature is that we (or just me?) do not receive any text, in the body of the msg. Just blank.