H
Huram Abi
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Photons have zero rest mass, so they are massless particles. They do have momentum, however.
Photons don't rest.
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Photons have zero rest mass, so they are massless particles. They do have momentum, however.
Photons don't rest.
Physicists feel otherwise. "Rest mass" is the name for a quantity that can be calculated for any particle, at rest or not, massless or massive.Considering that photons are never at rest, I don't find the rest mass at all useful in this discussion.
What invariant mass suggests that? "Invariant mass" is just another name for the rest mass.The invarient mass suggests that, infintesimally, photons do have mass.
Considering that photons are never at rest, I don't find the rest mass at all useful in this discussion.
The invarient mass suggests that, infintesimally, photons do have mass.
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Light not being able to escape the gravitational pull of a blackhole should be the first indication that photons have mass.
Not if General Relativity is correct. In GR it is the stress-energy tensor that is the source of gravitation, not the mass (which is not trivially defined in GR, as I understand it).Never thought of that. Is this valid?
No. It's discussing upper limits on the photon mass. In other words, experiments show that the photon mass must be less than some (really small) quantity. Experiments can't show that the mass is exactly zero; all they can do is show that there is no deviation from the results you'd expect if it were exactly zero, and so that the mass must be either zero or very close to it.Ok, can somebody translate this into English?
Rev. Mod. Phys. 43, 277 (1971): Terrestrial and Extraterrestrial Limits on The Photon Mass
It's a short little page. Is it saying photons actually do have mass?