Does a Photon Have Momentum?
Most recent answer: 09/10/2012
Q:
photon have zero rest mass how can it possiable its momemtum
- pintukumaryadav (age 18)
purnia bihar india
- pintukumaryadav (age 18)
purnia bihar india
A:
Yes it does. Although the photon has zero rest mass, it does have energy. From the relativistic relationships among Energy, Mass, and Momentum, E2 = (Moc2)2 + (pc)2, if the rest mass is zero then the momentum is give by p = E/c. Consider a photon bouncing directly back from a small mirror. It is observed by direct experimental measurement that if a laser beam is reflected from a mirror, the mirror will recoil with the same amount of momentum that the photon had (minus a tiny amount do the slight wavelength shift in the recoiling photon).
Even in classical electromagnetic theory a traveling wave caries energy and momentum in the same ratio.
LeeH
Even in classical electromagnetic theory a traveling wave caries energy and momentum in the same ratio.
LeeH
(published on 09/10/2012)