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The photoelectric effect and the Heisenberg uncertainty principle?
Einstein calculated that if light of frequency f descends up on a photoelectric surface then the maximum kinetic energy E of a resulting photoelectron can be calculated from hf = phi + E where h is Plank's constant and phi is the "work function" of the surface. Suppose our equipment is so precise that we can aim a laser with a frequency of exactly phi/h at a single atom in the surface. It seems to me that we will have a good estimate for the location of the electron while, at the same time, knowing its velocity is precisely 0 since its kinetic energy is 0. This appears to conflict with the Heisenberg uncertainty principle. Any ideas how to deal with this?
1 Answer
- ☮ VašekLv 51 decade agoFavorite Answer
The explanation is that your assumption alone contradicts the uncertainty principle. The frequency, together with the direction vector, is just some simple transformation of the photons' momentum, while aiming the laser to a single atom means a precise specification of their position.
