Photons denied a glimpse of their observer
Can photons tell if they're about to be watched? John Wheeler first proposed a means of resolving this bizarre possibility by coming up with a new twist on the double slit experiment almost 30 years ago. Now, physicists in France have performed the experiment for the first time (Science 315 966).
In 1978 John Wheeler pointed out that a photon could somehow know in advance whether an observation was going to be made, and change its behaviour to that of a wave or particle accordingly. To test for this possibility he thought of an experiment in which the decision to observe the photons is made only after they have been emitted.
De conclusie van het experiment:
Experimental realization of Wheeler’s delayed-choice GedankenExperiment
J-F. Roch, A. Aspect, P.Grangier in Science.
Our realization of Wheeler’s delayedchoice GedankenExperiment demonstrates beyond any doubt that the behavior of the photon in the interferometer depends on the choice of the observable which is measured, even when that choice is made at a position and a time such that it is separated from the entrance of the photon in the interferometer by a space-like interval.
In Wheeler’s words, since no signal traveling at a velocity less than that of light can connect these two events, “we have a strange inversion of the normal order of time. We, now, by moving the mirror in or out have an unavoidable effect on what we have a right to say about the already past history of that photon” (7). Once more, we find that Nature behaves in agreement with the predictions of Quantum Mechanics even in surprising situations where a tension with Relativity seems to appear (27).http://arxiv.org/PS_...610/0610241.pdf
Bewijst dit dat we het verleden kunnen beinvloeden?