- #1

LeonhardEuler

Gold Member

- 859

- 1

Here is why this confuses me: Correct me if I'm wrong, but I don't think it makes sense to speak of a "force" in QM, at least not one resembling a classical force because there really is no position in QM, so there can't be a second time derivative of position, and what I always (incorrectly?) took as the definition of force was [itex]\sum\vec{F}=m\vec{a}[/itex]. If there is no force there can be no force field. If there is no force field, then there is no wave in the force field. Usually in QM equations you have a "potential" instead of a force. I was thinking maybe light was a wave in electric and magnetic potential, but then I remembered Faraday's and Ampere's law. [itex]\oint\vec{E}\cdot ds[/itex] and [itex]\oint\vec{B}\cdot ds[/itex] are not necessarily zero around closed loops, so you can't speak of a potential without speaking about a particular path! And yet, light must clearly have some electromagnetic nature because it can push charges around in a circuit, for example in a radio (I'm using the word "light" in a more general sense than visible light). So what is light a wave in, if not [itex]\vec{E}[/itex] and [itex]\vec{B}[/itex] fields. And if it is not a wave in these how does it move charges. And if it is a wave in these, how does it get around the force problem? Thank you for reading all this!