According to Einstein E²=(mc²)²+(pc)². In the case of photons m would be equal to zero since photons are massless, so the equation simplifies to E²=(pc)². p represents momentum but because p=mv and mass is still zero, p would also be zero. Therefore E should also be equal to zero, but this doesn’t make sense since light must have energy (eg. solar energy). I hope I’ve explained my thoughts clearly and thanks to anyone who can help me understand.
In: Physics
You’re halfway there, the energy of a photon is indeed p*c. However, the equation for momentum is not m*v for objects moving at (or near) the speed of that, that’s just an approximation that we use for low speed objects. For a photon, its momentum is planck’s constant divided by its wavelength
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