Why is the speed of photons different?

  • #1

Summary:

I read the Feynman's book about the quantum electrodynamics and I realized, that he was talking about the different speed of photons - please why are photons travelling at different speed, the blue photons are faster that the red ones, for instance?

Main Question or Discussion Point

Hi,

I read the Feynman's book about the quantum electrodynamics and I realized, that he was talking about the different speed of photons. I know, that the light travel's "slower" in a material, but he is also talking about the different speed of photons. I read on the web, that some photons travel's faster than the ther ones because of different energy, but WHY? Please give me some deep answer - deep like Feynman's book, no less.
 

Answers and Replies

  • #2
phinds
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please why are photons travelling at different speed, the blue photons are faster that the red ones, for instance?
I think you must have misunderstood something. "red" and "blue" are just different frequencies in the EM spectrum and they all travel at the same speed, c (in a vacuum).
 
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  • #3
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This is why the speed of light you have read about is measured in vacuum(c).
In other mediums, due to different diffraction coefficients certain wavelengths are affected differently.
 
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