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I am very far from even understanding quantum physics theories but for all this experiment to be valid to begin with,the idea that superpositions exist must be

I am very far from even understanding quantum physics theories but for all this experiment to be valid to begin with,the idea that superpositions exist must be true, correct? What if what they're proving is really the abscence of a superposition state? I never understood how superposition can be verified independent of assumptions. In this case,how can Wigner measure the photon has veritcal and horizontal polarity at the same time? Lastly,could superposition be explained by human's limit of sampling reality? For example audio recorded at 10Hz means 10/samples of audio a second,a sort of audio-resolution. If our reality-resolution is low,some things might require ability to measure their state at a better time-space resolution than what humans can currently sample (or build equipment that can measure this)? But with limited time-space resolution it can appear as if the object is in two states at the same time. Sort of like watching a movie at a very slow frame rate and you capture a moment where half the screen is of one frame but the rest is of a different frame since the display is only half finished rendering the raster/rows. Apologies if I am being absolutley clueless.

maxander 8y ago
The classic demonstration of superposition is the double-slit experiment [0], where an experimenter shines a (coherent) light through a pair of slits at a screen (or fires a stream of electrons through a pair of slits, or small particles- it works with anything.) Because light is waves [1], light coming through one slit will interfere with light coming through the other slit, producing an interference pattern. But weirdly, this still happens if you turn the light source down so low that it emits only one photon at a time. In that case, the photon is in a superposition that travels through both slits, and the interference is between "the part of the superposition going through the right slit" and "the part of the superposition going through the left slit." So it's not a matter of our being unable to make detailed enough measurements; we can actually observe phenomena that directly indicate superposition happens. [0] https://en.wikipedia.org/wiki/Double-slit_experiment https://en.wikipedia.org/wiki/Double-slit_experiment [1] And so are electrons, particles, humans, etc.
phayes 8y ago
> for all this experiment to be valid to begin with,the idea that superpositions exist must be true, correct? Depends what you mean by "exist". All that needs to be true - and is true - is that QM provides an accurate model of the experiment. For many of us, QM is just probabilistic mechanics; i.e. probability theory applied to mechanics[1], and so long as you maintain the distinction between (epistemic) probability space states and (ontic) configuration space states (something the article under discussion here unfortunately fails to do), no ontic existence of [superposition] states is ever assumed in the first place. [1] More precisely, a natural and necessary generalisation of the classical, Kolmogorovian probability theory you might be familiar with (necessary because of the noncommuting random variables): https://news.ycombinator.com/item?id=19315457 https://news.ycombinator.com/item?id=19315457 See also: http://blogs.discovermagazine.com/cosmicvariance/files/2011/11/banks-qmblog.pdf http://blogs.discovermagazine.com/cosmicvariance/files/2011/...

maxander 8y ago

The classic demonstration of superposition is the double-slit experiment [0], where an experimenter shines a (coherent) light through a pair of slits at a screen (or fires a stream of electrons through a pair of slits, or small particles- it works with anything.) Because light is waves [1], light coming through one slit will interfere with light coming through the other slit, producing an interference pattern. But weirdly, this still happens if you turn the light source down so low that it emits only one photon at a time. In that case, the photon is in a superposition that travels through both slits, and the interference is between "the part of the superposition going through the right slit" and "the part of the superposition going through the left slit." So it's not a matter of our being unable to make detailed enough measurements; we can actually observe phenomena that directly indicate superposition happens. [0] https://en.wikipedia.org/wiki/Double-slit_experiment https://en.wikipedia.org/wiki/Double-slit_experiment [1] And so are electrons, particles, humans, etc.

phayes 8y ago

> for all this experiment to be valid to begin with,the idea that superpositions exist must be true, correct? Depends what you mean by "exist". All that needs to be true - and is true - is that QM provides an accurate model of the experiment. For many of us, QM is just probabilistic mechanics; i.e. probability theory applied to mechanics[1], and so long as you maintain the distinction between (epistemic) probability space states and (ontic) configuration space states (something the article under discussion here unfortunately fails to do), no ontic existence of [superposition] states is ever assumed in the first place. [1] More precisely, a natural and necessary generalisation of the classical, Kolmogorovian probability theory you might be familiar with (necessary because of the noncommuting random variables): https://news.ycombinator.com/item?id=19315457 https://news.ycombinator.com/item?id=19315457 See also: http://blogs.discovermagazine.com/cosmicvariance/files/2011/11/banks-qmblog.pdf http://blogs.discovermagazine.com/cosmicvariance/files/2011/...