4 ms·
Sorry - again, only HS physics - does that imply they have mass when moving ? (hmm - can you even have a photon at rest?) thanks!
by mech422 2y ago
Sorry - again, only HS physics - does that imply they have mass when moving ? (hmm - can you even have a photon at rest?)
thanks!
- itishappy 2y agoSorry, we're leaving HS physics with this one... Objects in motion have kinetic energy, and Einstein says mass and energy are equivalent. This means in a very real sense objects in motion have additional "relativistic mass". When you annihilate that photon it's energy is transferred to whatever absorbed it. Confused? You're not alone! Physicists are trying to move away from the terms "rest mass" and "relativistic mass" for reasons including one you've already identified: what does it even mean for a photon to be "at rest"? https://en.wikipedia.org/wiki/Mass_in_special_relativity https://en.wikipedia.org/wiki/Mass_in_special_relativity
- mech422 2y agoOh thanks! That article was interesting :-) Not gonna say I understood it...but it was interesting :-D
- oneshtein 2y agoWaves on water have zero rest mass, but they hit hard.