If you put 3 pigeons in two pigeonholes, two pigeons must be in one of them. Not so says quantum mechanics in a new paper [ Proc. Natl. Acad. Sci. vol. 113 pp. 532 – 535 ’16 ]. I can’t claim to understand the paper, despite auditing a course in QM in the past decade, but at least I do understand the terms they are throwing about. I plan to print it out and really give it a workout
The paper does involve something called a beam splitter, which splits photon waves into two parts. I’ve never understood how this works on a mechanistic level. Perhaps no such understanding is possible. Another thing I don’t understand is what happens when a photon wave (or particle) is reflected from a mirror. Perhaps no such understanding is possible. Another thing I don’t understand is how a photon is diffracted when it passes through a slit. It must in some way sense the edge of the slit. I’ve certainly watched waves being diffracted by a breakwater — just go up to the bar at the top of the Sears Tower in Chicago, get an estimate on a beer and look out at lake Michigan.
Can anyone out there help?