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Technically, pictures always represent the light emitted or reflected off objects, not the objects themselves (hence photo-graphy, "drawing with light"). Howev

Technically, pictures always represent the light emitted or reflected off objects, not the objects themselves (hence photo-graphy, "drawing with light"). However I agree that "Picture of light emitted just by a single trapped atom" would be a more accurate title and yet still incredibly cool.

jessriedel 9y ago
First, reflection and emission are not the same. But more importantly, the only sensible definition of "seeing an object" is that the angular distribution of the light entering your eyeball carries some information about the geometric shape of the object. Otherwise, we could just as correctly say that when we look at dog we are seeing the sun or the overhead florescent bulbs; that's where the photons came from. Likewise, if I put a piece of strongly frosted glass between me and the dog, it would be misleading to say I can "see the dog" even if the photons that come from the dog reach my eye. The key reason this is wrong is that strongly frosted glass scrambles the information.
- aphextron 9y ago
  >Otherwise, we could just as correctly say that when we look at dog we are seeing the sun or the overhead florescent bulbs; that's where the photons came from No, they didn't. The energy came from the sun, however the photons which are collected in your retina to form the image of a dog were emitted from the dog itself. "Reflection" is just the stimulation of photon emission via radiation. https://en.wikipedia.org/wiki/Photoelectric_effect https://en.wikipedia.org/wiki/Photoelectric_effect
  - jessriedel 9y ago
    You're gesturing at an unconvincing objection: that there is no difference between reflection and emission because there is a sense in which light passing through matter is continuously being absorbed and re-emitted. (I say "gesturing" because you don't actually know the physics; it is completely different than either stimulated emission or the photoelectric effect, which you could tell by reading the Wikipedia articles.) Explaining why this objection is boring and unconvincing would ultimately be a long discussion in the philosophy of science ("how can we keep using folk terminology that presumes a sharp devision between two concepts when a theory of physics suggests they are actually just part of a continuum?"), but you can get a sense of that by noticing that emission generally involves a change in the frequency of light while reflection does not.
    - aphextron 9y ago
      >(I say "gesturing" because you don't actually know the physics; it is completely different than either stimulated emission or the photoelectric effect, which you could tell by reading the Wikipedia articles.) Well, clearly you're a fucking idiot. See, I can use ad hominem to make a meaningless non-point as well.

jessriedel 9y ago

First, reflection and emission are not the same. But more importantly, the only sensible definition of "seeing an object" is that the angular distribution of the light entering your eyeball carries some information about the geometric shape of the object. Otherwise, we could just as correctly say that when we look at dog we are seeing the sun or the overhead florescent bulbs; that's where the photons came from. Likewise, if I put a piece of strongly frosted glass between me and the dog, it would be misleading to say I can "see the dog" even if the photons that come from the dog reach my eye. The key reason this is wrong is that strongly frosted glass scrambles the information.

aphextron 9y ago
>Otherwise, we could just as correctly say that when we look at dog we are seeing the sun or the overhead florescent bulbs; that's where the photons came from No, they didn't. The energy came from the sun, however the photons which are collected in your retina to form the image of a dog were emitted from the dog itself. "Reflection" is just the stimulation of photon emission via radiation. https://en.wikipedia.org/wiki/Photoelectric_effect https://en.wikipedia.org/wiki/Photoelectric_effect
- jessriedel 9y ago
  You're gesturing at an unconvincing objection: that there is no difference between reflection and emission because there is a sense in which light passing through matter is continuously being absorbed and re-emitted. (I say "gesturing" because you don't actually know the physics; it is completely different than either stimulated emission or the photoelectric effect, which you could tell by reading the Wikipedia articles.) Explaining why this objection is boring and unconvincing would ultimately be a long discussion in the philosophy of science ("how can we keep using folk terminology that presumes a sharp devision between two concepts when a theory of physics suggests they are actually just part of a continuum?"), but you can get a sense of that by noticing that emission generally involves a change in the frequency of light while reflection does not.
  - aphextron 9y ago
    >(I say "gesturing" because you don't actually know the physics; it is completely different than either stimulated emission or the photoelectric effect, which you could tell by reading the Wikipedia articles.) Well, clearly you're a fucking idiot. See, I can use ad hominem to make a meaningless non-point as well.