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smk222
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i read some where that four momentum of photon is null vector that's why photon have zero rest mass.but i cannot get it.please help
https://www.physicsforums.com/threads/four-momentum-of-a-photon.308273/smk222 said:i read some where that four momentum of photon is null vector that's why photon have zero rest mass.but i cannot get it.please help
Photon rest mass refers to the theoretical mass that a photon would have if it were at rest. However, since photons always travel at the speed of light, they do not have a rest mass.
Even though photons do not have a rest mass, they do have momentum and energy. This is due to their wave-like properties and the fact that they travel at the speed of light. The equation E=mc² shows the relationship between energy, mass, and the speed of light.
No, all photons have the same mass of zero. This is because they all travel at the speed of light, which is a universal constant. Therefore, the equation E=mc² only applies to particles with a rest mass.
Understanding photon rest mass is important for many reasons. It helps us better understand the properties of light and how it behaves. It also has implications in fields such as quantum mechanics and cosmology.
Regular mass refers to the amount of matter in an object, while photon rest mass is a theoretical concept for a particle that does not have a rest mass. Additionally, regular mass can be measured and has inertia, while photon rest mass cannot be measured and does not have inertia.