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The explanation given is at the level of classical electromagnetism, and is sufficient to explain and predict experiments with regular light. If you want an ex

The explanation given is at the level of classical electromagnetism, and is sufficient to explain and predict experiments with regular light. If you want an explanation and prediction of what happens at the level of single photons, you need more structure from the theory of quantum optics. But briefly the filter at angle T does a measurement on the photon in the basis {T, T+pi/2}, and you end up seeing the photon on the other side of the filter only with whatever probability the photon has for being in state |T>, as opposed to state |T+pi/2>. So, filters are inherently destructive and fewer and fewer photons pass through each subsequent filter. And a photon that makes it through a filter at angle T, now has a new state |T>.

jiggawatts 4y ago
The thing is that there is no actual evidence that “single photons” exist in the electromagnetic field. That last bit is important: photons are a mathematical shorthand for dealing with emission and absorption by atomic orbitals. They’re not an explanation for continuous waves in between, but the mathematics largely works anyway because photons are very similar to how one would do a Monte Carlo numerical simulations of continuous wave phenomena. This has resulted in an unbelievable amount of confusion…
- oh_my_goodness 4y ago
  There is lots of evidence for photons in the EM field, beginning with Planck's invention of photons. http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Planck%20(1900),%20Distribution%20Law.pdf http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Planck%20(... If you make the energy in a mode of the EM field continuous, you get the famous 'ultraviolet catastrophe.' This holds whether the matter involved has a continuous emission spectrum or not.
  - renox 4y ago
    I'm not so sure: 'black body' are made of atoms, atoms emits lights only on certain frequency due to the way electrons orbitals are structured, with discrete energy levels, but I don't see how this is related to EM fields themselves..
    - wyager 4y ago
      Free electrons also emit blackbody radiation. Photon quantization has nothing to do with the energy levels of atoms. It is a very fundamental property of the universe - you can tell because the only relevant constant is planck's constant.
      - renox 4y ago
        I didn't say that light isn't quantized, I just said that for me blackbody radiation of ordinary matter isn't a convincing proof that light is quantized.. As for free electrons emitting blackbody radiations can you give me a reference? If you're talking about a wiggle (https://en.wikipedia.org/wiki/Wiggler_(synchrotron) https://en.wikipedia.org/wiki/Wiggler_(synchrotron)) I don't see how this is related to the issue.
        oh_my_goodness 4y ago
        The sun is full of free charged particles.
        wyager 4y ago
        So there are two things we should identify separately that go under the name "quantization". One is that when we send out a single photon worth of energy, even in an isotropic or other multi-path emission pattern, we only ever seem to detect a single photon. You can prove this with a half mirror and two detectors. This is kind of weird - not clear how this works, and the core question driving different quantum interpretations. Second is that the energy level of a single photon detection is based on the constraint that Et=h (t is period), also written E=hf. This is not related to atomic properties of the detector. Why? Equation does not depend on any variable of the detector. Same goes for Px=h. (Momentum/wavelength relationship.) You can prove that one with two razor blades close together. Same relationship, but along space axes instead of time. Also for uncertainty principle - reinterpret EPtx as the variance of their distributions. All of this is some sort of fundamental constraint of the universe around quantities of dimension force*time*distance (action). Not related to atoms per se. Not that I understand why this constraint exists. I know some ways to think about it mathematically, but not intuitively.
- aaaaaaaaaaab 4y ago
  Hmmm… citation needed?
  - jiggawatts 4y ago
    I know it's not exactly Nature, but I like this one for the approachable and intuitive explanation: https://www.youtube.com/watch?v=SDtAh9IwG-I https://www.youtube.com/watch?v=SDtAh9IwG-I Fundamentally, you have to believe in nonsense such as kilometer-sized particles that are also infinitesimal if your point of view is that photons are particles. Many of the "mysteries" of Quantum Mechanics vanish if keep in the back of your mind that QM is just a bag of mathematical tricks that "work" in specific scenarios to solve practical problems, but aren't a model of "what actually occurs". Practically all of it is restricted to statistical predictions related to matter. Remove matter or remove statistics and then the models are no longer valid. I'm not making this up. Go dig up any of the original QM papers and these assumptions and/or constraints are called out in the first few paragraphs.
    - wbl 4y ago
      The existence of objects is merely a model of sense data.
    - messe 4y ago
      > Many of the "mysteries" of Quantum Mechanics vanish if keep in the back of your mind that QM is just a bag of mathematical tricks that "work" in specific scenarios to solve practical problems, but aren't a model of "what actually occurs". They also tend to start vanishing once you get to studying Quantum Field Theory, which based on your comments I'm not convinced you have. Field Quanta very much "exist" (not getting into a debate on platonism here), and the debate between paticle/wave doesn't. > I'm not making this up. No, somebody else is, and you're buying it.
      - jiggawatts 4y ago
        Yes, some crazy YouTube video logger named Schrödinger. I wouldn't trust him either. What does he know? You're basically arguing that the assumptions of QM theory that is in many of the older papers for some reason stopped mattering. That they've been invalidated... somehow, instead of simply being dropped for brevity in newer papers, assuming that everyone knows them already. All I'm saying is that if you go back to the original version of the theory, they were quite clear about the scope: a statistical theory that applies to ensembles of atoms. In theoretical Physics, especially when dealing with phenomena outside of normal human experience, you have to be very careful with your assumptions otherwise you can make yourself believe all sorts of nonsense. Such as wave function collapse. Or spooky action at a distance. Both of which stem from a misunderstanding of the limits of the scope of a statistical theory that only applies to some types of physical objects.
- kergonath 4y ago
  > The thing is that there is no actual evidence that “single photons” exist in the electromagnetic field. That last bit is important: photons are a mathematical shorthand for dealing with emission and absorption by atomic orbitals That is not true, unless I completely misunderstood what you are trying to say. Photons exist in contexts without any atom involved, e.g. particle/antiparticle pair creation or annihilation. The gamma photons emitted during radioactive decay have nothing to do with orbitals either. Besides, single photons have been observed. It was an important part of the Young slits experiment. Alain Aspect’s experiments also depend on the existence of single photon pairs. How would they work if photons were not a thing?
  - fsh 4y ago
    The double-slit experiment is no proof for the existence of single photons. It can be fully explained (at any light intensity) by assuming a classical electric field. The "clicks" of a "single-photon detector", such as a photomultiplier, only require the existence of quantized charges (electrons).
    - kergonath 4y ago
      No, not really. If the amplitude of the EM wave is enough to make an electron jump, all the electrons with an available energy level would jump across the whole detector. To have a single detection in a given region of the detector, you need a localised energy transfer. At this point we’re just reinventing photons.
      - phkahler 4y ago
        >> At this point we’re just reinventing photons. Or is it another case of "wave function collapse"? Remember that diffraction grating work too, and they rely on the wave nature of light. It is sometimes said (and can be modeled) that light takes every path from source to destination and the diffraction grating causes many paths to cancel out so it appears to go specific ways. Mirror reflection can also be modeled this way, and making periodic scratches will turn it into a diffraction grating. In the end, a photon detection is like a "measurement" that collapses the reflected wave function. Photons are never observed "in flight" they are only detected when they hit something. In between they may as well BE a wave function.
- nextaccountic 4y ago
  One could equivalently say that the thing that really exists is the photon, that is, light is a particle and not a wave, and the weird stuff comes from how photons move through space. That was the view of Feynman at least, espoused in his pop science book "QED: The Strange Theory of Light and Matter" Actually I just checked, on page 15: > I want to emphasize that light comes in this form - particles. It is very important to know that light behaves like particles, especially for those of you who have gone to school, where you were probably told something about light behaving like waves. Anyway I say "equivalently" because this is just another way to conceptualize the same theory (and make the same predictions), it's not new physics
- Strilanc 4y ago
  You're suggesting that the EM field doesn't need to be quantized if everything it interacts with is quantized, so that the non-quantized parts can never be brought to bear and observed?

jiggawatts 4y ago

The thing is that there is no actual evidence that “single photons” exist in the electromagnetic field. That last bit is important: photons are a mathematical shorthand for dealing with emission and absorption by atomic orbitals. They’re not an explanation for continuous waves in between, but the mathematics largely works anyway because photons are very similar to how one would do a Monte Carlo numerical simulations of continuous wave phenomena. This has resulted in an unbelievable amount of confusion…

oh_my_goodness 4y ago
There is lots of evidence for photons in the EM field, beginning with Planck's invention of photons. http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Planck%20(1900),%20Distribution%20Law.pdf http://hermes.ffn.ub.es/luisnavarro/nuevo_maletin/Planck%20(... If you make the energy in a mode of the EM field continuous, you get the famous 'ultraviolet catastrophe.' This holds whether the matter involved has a continuous emission spectrum or not.
- renox 4y ago
  I'm not so sure: 'black body' are made of atoms, atoms emits lights only on certain frequency due to the way electrons orbitals are structured, with discrete energy levels, but I don't see how this is related to EM fields themselves..
  - wyager 4y ago
    Free electrons also emit blackbody radiation. Photon quantization has nothing to do with the energy levels of atoms. It is a very fundamental property of the universe - you can tell because the only relevant constant is planck's constant.
    - renox 4y ago
      I didn't say that light isn't quantized, I just said that for me blackbody radiation of ordinary matter isn't a convincing proof that light is quantized.. As for free electrons emitting blackbody radiations can you give me a reference? If you're talking about a wiggle (https://en.wikipedia.org/wiki/Wiggler_(synchrotron) https://en.wikipedia.org/wiki/Wiggler_(synchrotron)) I don't see how this is related to the issue.
      - oh_my_goodness 4y ago
        The sun is full of free charged particles.
      - wyager 4y ago
        So there are two things we should identify separately that go under the name "quantization". One is that when we send out a single photon worth of energy, even in an isotropic or other multi-path emission pattern, we only ever seem to detect a single photon. You can prove this with a half mirror and two detectors. This is kind of weird - not clear how this works, and the core question driving different quantum interpretations. Second is that the energy level of a single photon detection is based on the constraint that Et=h (t is period), also written E=hf. This is not related to atomic properties of the detector. Why? Equation does not depend on any variable of the detector. Same goes for Px=h. (Momentum/wavelength relationship.) You can prove that one with two razor blades close together. Same relationship, but along space axes instead of time. Also for uncertainty principle - reinterpret EPtx as the variance of their distributions. All of this is some sort of fundamental constraint of the universe around quantities of dimension force*time*distance (action). Not related to atoms per se. Not that I understand why this constraint exists. I know some ways to think about it mathematically, but not intuitively.
aaaaaaaaaaab 4y ago
Hmmm… citation needed?
- jiggawatts 4y ago
  I know it's not exactly Nature, but I like this one for the approachable and intuitive explanation: https://www.youtube.com/watch?v=SDtAh9IwG-I https://www.youtube.com/watch?v=SDtAh9IwG-I Fundamentally, you have to believe in nonsense such as kilometer-sized particles that are also infinitesimal if your point of view is that photons are particles. Many of the "mysteries" of Quantum Mechanics vanish if keep in the back of your mind that QM is just a bag of mathematical tricks that "work" in specific scenarios to solve practical problems, but aren't a model of "what actually occurs". Practically all of it is restricted to statistical predictions related to matter. Remove matter or remove statistics and then the models are no longer valid. I'm not making this up. Go dig up any of the original QM papers and these assumptions and/or constraints are called out in the first few paragraphs.
  - wbl 4y ago
    The existence of objects is merely a model of sense data.
  - messe 4y ago
    > Many of the "mysteries" of Quantum Mechanics vanish if keep in the back of your mind that QM is just a bag of mathematical tricks that "work" in specific scenarios to solve practical problems, but aren't a model of "what actually occurs". They also tend to start vanishing once you get to studying Quantum Field Theory, which based on your comments I'm not convinced you have. Field Quanta very much "exist" (not getting into a debate on platonism here), and the debate between paticle/wave doesn't. > I'm not making this up. No, somebody else is, and you're buying it.
    - jiggawatts 4y ago
      Yes, some crazy YouTube video logger named Schrödinger. I wouldn't trust him either. What does he know? You're basically arguing that the assumptions of QM theory that is in many of the older papers for some reason stopped mattering. That they've been invalidated... somehow, instead of simply being dropped for brevity in newer papers, assuming that everyone knows them already. All I'm saying is that if you go back to the original version of the theory, they were quite clear about the scope: a statistical theory that applies to ensembles of atoms. In theoretical Physics, especially when dealing with phenomena outside of normal human experience, you have to be very careful with your assumptions otherwise you can make yourself believe all sorts of nonsense. Such as wave function collapse. Or spooky action at a distance. Both of which stem from a misunderstanding of the limits of the scope of a statistical theory that only applies to some types of physical objects.
kergonath 4y ago
> The thing is that there is no actual evidence that “single photons” exist in the electromagnetic field. That last bit is important: photons are a mathematical shorthand for dealing with emission and absorption by atomic orbitals That is not true, unless I completely misunderstood what you are trying to say. Photons exist in contexts without any atom involved, e.g. particle/antiparticle pair creation or annihilation. The gamma photons emitted during radioactive decay have nothing to do with orbitals either. Besides, single photons have been observed. It was an important part of the Young slits experiment. Alain Aspect’s experiments also depend on the existence of single photon pairs. How would they work if photons were not a thing?
- fsh 4y ago
  The double-slit experiment is no proof for the existence of single photons. It can be fully explained (at any light intensity) by assuming a classical electric field. The "clicks" of a "single-photon detector", such as a photomultiplier, only require the existence of quantized charges (electrons).
  - kergonath 4y ago
    No, not really. If the amplitude of the EM wave is enough to make an electron jump, all the electrons with an available energy level would jump across the whole detector. To have a single detection in a given region of the detector, you need a localised energy transfer. At this point we’re just reinventing photons.
    - phkahler 4y ago
      >> At this point we’re just reinventing photons. Or is it another case of "wave function collapse"? Remember that diffraction grating work too, and they rely on the wave nature of light. It is sometimes said (and can be modeled) that light takes every path from source to destination and the diffraction grating causes many paths to cancel out so it appears to go specific ways. Mirror reflection can also be modeled this way, and making periodic scratches will turn it into a diffraction grating. In the end, a photon detection is like a "measurement" that collapses the reflected wave function. Photons are never observed "in flight" they are only detected when they hit something. In between they may as well BE a wave function.
nextaccountic 4y ago
One could equivalently say that the thing that really exists is the photon, that is, light is a particle and not a wave, and the weird stuff comes from how photons move through space. That was the view of Feynman at least, espoused in his pop science book "QED: The Strange Theory of Light and Matter" Actually I just checked, on page 15: > I want to emphasize that light comes in this form - particles. It is very important to know that light behaves like particles, especially for those of you who have gone to school, where you were probably told something about light behaving like waves. Anyway I say "equivalently" because this is just another way to conceptualize the same theory (and make the same predictions), it's not new physics
Strilanc 4y ago
You're suggesting that the EM field doesn't need to be quantized if everything it interacts with is quantized, so that the non-quantized parts can never be brought to bear and observed?