Is a photon's momentum transverse?

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SUMMARY

The momentum of a photon is definitively in the direction of its motion, contrary to the misconception that it may be transverse due to its wave-like properties. This conclusion aligns with classical electromagnetic wave theory and the behavior of photons in interactions, such as the photoelectric effect. When a photon strikes an electron, the transverse momentum of the resulting photoelectron must be balanced by the recoiling atom or lattice, reinforcing the concept that photon momentum is aligned with its trajectory.

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ConradDJ
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I understand that light propagates as a transverse wave -- does this mean that the momentum carried by a photon is perpendicular to its path?

Thanks for the help.
 
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No. The momentum of a photon (and of an electromagnetic wave) is in the direction of motion.

(Don't think of the photon as wiggling transversely as it travels; keep the classical electromagnetic wave picture and the photon picture separate.)
 
As Doc Al states, the momentum of a photon is only in the direction of motion. If the photon strikes an electron and produces a photo electron (photoelectric effect). The transverse momentum of the electron (relative to the incoming photon direction) has to be balanced by the transverse momentum of the recoiling atom or lattice.
 

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