Check out the math & physics courses that I mentioned (many of which are free!) and support this channel by going to https://brilliant.org/Sabine/ where you can create your Brilliant account. The first 200 will get 20% off the annual premium subscription. The delayed choice quantum eraser is one of the weirdest, if not THE weirdest, experiments in quantum mechanics. It supposedly rewrites the past because the choice of a measurement changes what happened in another measurement earlier. In this video I explain why this is not what's happening. The quantum eraser isn't remotely as weird as you may have heard. Sean Carroll's blogpost is here: https://www.preposterousuniverse.com/blog/2019/09/21/the-notorious-delayed-choice-quantum-eraser/ Technical remark: You can find a lot of webpages saying that the envelope of the double-slit interference pattern is that of the single-slit diffraction pattern. Note that this is is only approximately correct. You can support our channel on Patreon: https://www.patreon.com/Sabine 0:00 Intro 1:45 The Double Slit 4:17 Entanglement 4:53 The Quantum Eraser 9:03 What they didn't tell you 11:45 Sponsor Message #physics #quantum