[infinitethoughts]

Science hopes to change events that have already occurred
Patrick Barry
Sunday, January 21, 2007
San Francisco Chronicle.


In 1986, Carroll Alley at the University of Maryland at College Park, found a way to test this idea using a more practical set-up: an interferometer which lets a photon take either one path or two after passing through a beam splitter. Sure enough, the photon's path depended on a choice made after the photon had to "make up its mind." Other groups have confirmed similar results, and at first blush this appears to show the present affecting the past. Most physicists, however, take the view that you can't say which path the photon took before the measurement is made. In other words, still no unambiguous evidence for retrocausality.

That's where John Cramer comes in.....