Jan 302020
The “Quantum Eraser” experiment is simple enough to understand… but the results make my brain hurt. Start with the double-slit experiment that shows the particle/wave duality of photons. Weird enough from an everyday perspective, but the interference patterns are comprehensible. But when you shoot individual photons, rather than vast numbers, they *still* end up producing interference patterns. Buh?
That should be adequate strangeness. But wait! There’s more!
A modification of the experiment that seems to make photons change what they’re doing if their entangled partners are observed. More to the point, this collapse in the wave function propagates *backwards* in time.