3 ms·

This is a nice article, but it feels like it leaves a half of the puzzle to the table. We know by everyday experience that photons _do_ have some time- and plac

This is a nice article, but it feels like it leaves a half of the puzzle to the table. We know by everyday experience that photons _do_ have some time- and place-varying properties: my WiFi has a perfect strength here, but absolutely zero at my friend's house 5 kms away. The photons emitted by my LED lamp are not a static field: I can switch it off by pressing a button so it's time-varying. The article acknowledges place only in this short sentence in the end: > This means that adding a quantum to a system has an effect that extends across the entire system. That makes it problematic to talk about the location of a photon. But then leaves the experience gap between the model and our everyday experience totally without discussion.

GolDDranks 6y ago
Btw. I have an impression that time- and place-local behaviour can be modelled as a collection of photons that destructively interfere "elsewhere" than where we tend to actually see light. Fourier transform seems to play a big role here.
- krastanov 6y ago
  Your statement is not very rigorous, but the intuition it provides is spot on. It is pretty much exactly this intuition I convey the first time I teach such topics.
noobermin 6y ago
This is written by a theorist so they do leave the important bit out. Of course, you know just from fourier analysis the uncertainty principle. The thing is treating photons as plane waves is an approximation (a fine one for most things, particularly theoretical calculations). A better approximation is thinking of photons as wave packets that thus have some localization but not so defined as to make their bandwidth too wide (so they can be considered monochromatic). The important thing to remember is that photons, like the very idea of a planewave is always an idealized approximation.

3 ms·

This is a nice article, but it feels like it leaves a half of the puzzle to the table. We know by everyday experience that photons _do_ have some time- and plac

by GolDDranks 6y ago

GolDDranks 6y ago
Btw. I have an impression that time- and place-local behaviour can be modelled as a collection of photons that destructively interfere "elsewhere" than where we tend to actually see light. Fourier transform seems to play a big role here.
- krastanov 6y ago
  Your statement is not very rigorous, but the intuition it provides is spot on. It is pretty much exactly this intuition I convey the first time I teach such topics.
noobermin 6y ago
This is written by a theorist so they do leave the important bit out. Of course, you know just from fourier analysis the uncertainty principle. The thing is treating photons as plane waves is an approximation (a fine one for most things, particularly theoretical calculations). A better approximation is thinking of photons as wave packets that thus have some localization but not so defined as to make their bandwidth too wide (so they can be considered monochromatic). The important thing to remember is that photons, like the very idea of a planewave is always an idealized approximation.