Hardy's Paradox | Quantum Double Double Slit Experiment

Need a last minute holiday gift idea? Go to https://www.brilliant.org/minutephysics for 20% off a premium subscription to Brilliant (can be given as a gift). Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 This video is about Hardy's Paradox, wherein an electron and positron (or photons polarized horizontally and vertically) pass through Mach-Zehnder interferometers that overlap such that the particles have a chance of annihilating. If they do annihilate, then the interference pattern changes and there is a probability for both particles to be detected in the "dark arms" of the detector, that is, where previously there was no probability for detection for either particle. The paradox has implications for local realism, contextuality, lorentz elements of reality, and has been used as an experimental setup for weak measurements. Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich