imran Messages 17 Reaction score 0 Thread starter Jan 24, 2005 #1 what is rest mass? why does a photon have rest mass zero?
Jake Messages 90 Reaction score 0 Jan 24, 2005 #2 Rest mass is the mass an object has when you are in its frame of refrence (IE its stationary to you). Photons have rest mass zero because they dont have any mass :)
Rest mass is the mass an object has when you are in its frame of refrence (IE its stationary to you). Photons have rest mass zero because they dont have any mass :)