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This is a horrendous article, clearly written by someone who doesn’t grasp the basics. I gave up when they conflated how the double-slit experiment demonstrates
by cfadvan 8y ago
This is a horrendous article, clearly written by someone who doesn’t grasp the basics. I gave up when they conflated how the double-slit experiment demonstrates wave-particle duality with a demonstration of superposition. I can’t believe how much of a joke SciAm has become, it makes me sad.
- pessimist 8y agoYour criticism is totally incorrect. In fact the 2-slit experiment does demonstrate superposition. Wave-particle duality and superposition of states are really just complementary ways of describing the same situation. To understand this, please try to read any undergrad level treatment of quantum mechanics. For example - See Feynman's lectures volume 3.
- cfadvan 8y agoI have that right here, can you give me a page number?
- pessimist 8y agoPlease read chapter 3 "Probability Amplitudes". http://www.feynmanlectures.caltech.edu/III_03.html http://www.feynmanlectures.caltech.edu/III_03.html "When a particle can reach a given state by two possible routes, the total amplitude for the process is the sum of the amplitudes for the two routes considered separately. In our new notation we write that ⟨x|s⟩both holes open=⟨x|s⟩through 1+⟨x|s⟩through 2. (3.4)"
- kylnew 8y agoI’m admittedly pretty basic on the subject matter myself and wouldn’t have been able to notice that. Any suggested light reading that would clarify this distinction?
- cfadvan 8y agoI’m not sure about light reading, but http://theoreticalminimum.com http://theoreticalminimum.com is a great starting point.
- alanbernstein 8y agoThis is amazing, I've been looking for something like this for years. Now I just need to find the time to watch it...
- russdill 8y agoYou can derive the result by treating the particle like a wave, but that is clearly a false/incomplete model. There is only one particle, the only thing it can be interfering with is itself. It's in a superposition of going through both slits.
- cfadvan 8y agoA single photon will register one click on the detector, it’s only with an ensemble of many photons that an interference pattern emerges.
- roywiggins 8y agoYou will build up an interference pattern if you fire single photons, one at a time, spread out over as long a time period as you like.
- SAI_Peregrinus 8y agoYou can even do it with electrons. It's easier to fire single electrons, so that tends to be what's done for such an experiment.
- goldenkey 8y agoEverything. Isolation/coherency, of course, becomes harder with larger. https://medium.com/the-physics-arxiv-blog/physicists-smash-record-for-wave-particle-duality-462c39db8e7b https://medium.com/the-physics-arxiv-blog/physicists-smash-r...
- axilmar 8y agoSince the interference pattern is built over time, how do we know a particle is actually a wave that interferes with itself and not a particle that selects a different path from a set each time it is fired?
- ben_w 8y ago
- n4r9 8y agoIt has everything to do with superposition. A photon can only exhibit wave-like effects (i.e. interference) as long as its position ('x') state exists in a superposition. Measuring which slit the particle travels through collapses the particle's position into a pure state, thereby removing the interference effect.