27 ms·
When you put a photon in a stationary box, the "relativistic mass" of the photon becomes part of the "rest mass" of the photon-box system. You can't ignore it.
by tardedmeme 5mo ago
When you put a photon in a stationary box, the "relativistic mass" of the photon becomes part of the "rest mass" of the photon-box system. You can't ignore it.