3 ms·

They still transmitted light, they just called it a wave instead of a particle. Am I missing something?

by hasenj 9y ago

tbrownaw 9y ago
Yes, you're missing whatever's hidden behind the journal paywall. It's been way to long since my one quantum physics class, but looking at the pretty pictures I think they got their photon to interfere destructively with itself over the entire length of the transmission channel between a pair of beam splitters. Which I don't think is possible with ordinary waves (say in water), which I suppose is probably what the big deal is.
- TheOtherHobbes 9y ago
  If you go Full Copenhagen and start thinking about QM as a calculus of probability densities in physical systems it begins to make a lot more sense than trying to think about it as an impossibly weird version of Newtonian mechanics for waves+particles+wtf. It means you can stop playing "Where's the photon?" and accept that these experiments are doing spatially distributed probabilistic computing. In this view there is no photon - there's only a map of possible photon-like event positions distributed in spacetime, and one or more end-points tuned to pick up photon-like events by sampling the map at specific spacetime locations. The weird part is the way that interactions between the map distributions and the end-points are completely unintuitive, and you can do neat tricks like constraining probabilities by repeatedly connecting to an end-point, and creating dead areas where the probability of an event is zero but which don't "block" events around them. That just emphasises that the Newtonian-ish view is the wrong model. The right view is still TBD, but it seems to be some kind of holistic summary view that somehow - no one can even begin to guess how - creates a map by integrating over all possible interactions. This is not what we're used to, but discovering that reality doesn't do what we expect is the point of science, so that's not a bad thing.
  - varjack 9y ago
    Please stop waving your hands. I prefer the deBroglie-Bohm interpretation where you have both a particle and a wave. Changing the shape of the wave by changing site B setup changes where the particle ends up, even if the particle does not leave site A. (However, for this experiment to work, there should be a chance for the particle to travel from A to B, otherwise the pilot wave won't travel either)
tzs 9y ago
I have no idea if this is relevant to this experiment, but it illustrates how a path that had no light sent down it can affect light that went down another path: https://en.wikipedia.org/wiki/Elitzur%E2%80%93Vaidman_bomb_tester https://en.wikipedia.org/wiki/Elitzur%E2%80%93Vaidman_bomb_t...

They still transmitted light, they just called it a wave instead of a particle. Am I missing something?

by hasenj 9y ago

They still transmitted light, they just called it a wave instead of a particle. Am I missing something?

Yes, you're missing whatever's hidden behind the journal paywall. It's been way to long since my one quantum physics class, but looking at the pretty pictures I think they got their photon to interfere destructively with itself over the entire length of the transmission channel between a pair of beam splitters. Which I don't think is possible with ordinary waves (say in water), which I suppose is probably what the big deal is.

TheOtherHobbes 9y ago
If you go Full Copenhagen and start thinking about QM as a calculus of probability densities in physical systems it begins to make a lot more sense than trying to think about it as an impossibly weird version of Newtonian mechanics for waves+particles+wtf. It means you can stop playing "Where's the photon?" and accept that these experiments are doing spatially distributed probabilistic computing. In this view there is no photon - there's only a map of possible photon-like event positions distributed in spacetime, and one or more end-points tuned to pick up photon-like events by sampling the map at specific spacetime locations. The weird part is the way that interactions between the map distributions and the end-points are completely unintuitive, and you can do neat tricks like constraining probabilities by repeatedly connecting to an end-point, and creating dead areas where the probability of an event is zero but which don't "block" events around them. That just emphasises that the Newtonian-ish view is the wrong model. The right view is still TBD, but it seems to be some kind of holistic summary view that somehow - no one can even begin to guess how - creates a map by integrating over all possible interactions. This is not what we're used to, but discovering that reality doesn't do what we expect is the point of science, so that's not a bad thing.
- varjack 9y ago
  Please stop waving your hands. I prefer the deBroglie-Bohm interpretation where you have both a particle and a wave. Changing the shape of the wave by changing site B setup changes where the particle ends up, even if the particle does not leave site A. (However, for this experiment to work, there should be a chance for the particle to travel from A to B, otherwise the pilot wave won't travel either)

tzs 9y ago

I have no idea if this is relevant to this experiment, but it illustrates how a path that had no light sent down it can affect light that went down another path: https://en.wikipedia.org/wiki/Elitzur%E2%80%93Vaidman_bomb_tester https://en.wikipedia.org/wiki/Elitzur%E2%80%93Vaidman_bomb_t...