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Grand-Tension8668 OP t1_j8jz4i7 wrote

Reply to comment by platoprime in When measuring the wavelength of EM radiation... what's actually being measured? by Grand-Tension8668

u/shikuto's comment got me to sort of picture how EM fields are waves (they're traveling through space as they oscillate, after all, which is all a wave is), but it's still surprising to me to say that the change in polarity is actually a locational change, if that's what you're saying.

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platoprime t1_j8k2kyv wrote

No I don't mean to say polarity is spatial movement. Polarity is a change in the intensity of the electromagnetic field along a line over time.

However it's important to understand that photons are not localized until they interact with something. When they travel through space they don't have definite positions or momentums.

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karantza t1_j8kcf9s wrote

It's definitely not a locational change, but it does have a direction and "intensity", which drawings often represent as if it were a distance.

The electromagnetic field is a vector field, so it points in a real direction, and that gives us polarization. So as light travels in a straight line, oscillating in intensity between the E and B fields over time, those fields do have a direction, but no distance offset from the beam path.

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shikuto t1_j8m27fx wrote

It looks like you managed to tag someone with a 1-character difference from my username. I wonder what the chances of that are. Anyhow, I’m the one that supplied the assistance, not the innocent u/shikoto - please leave them out of this. I will take the punishment.

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