4 ms·
Energy gravitates. Photons have energy, therefore photons gravitate. Photons only have zero /rest mass/, not zero total mass.
by pja 6y ago
Energy gravitates. Photons have energy, therefore photons gravitate. Photons only have zero /rest mass/, not zero total mass.
- brabel 6y agoPhotos by definition don't have a rest mass because they are never at rest. They must always travel at the speed of light, which means they don't experience time, so rest does not even make sense for a photon.
- jlokier 6y agoThat makes sense in English, however "rest mess" is also a technical and mathematical term, and in that terminology it has the value zero for photons.