Editing Openai/6897769e-4ee4-800f-aba5-69cca34f701c (section)

==== Physical facts to keep: light is an electromagnetic field; a free photon has two polarization (helicity) states ±1. On a spherical wavefront (Huygens picture), the E and B vectors are tangential to the sphere and orthogonal to the radial propagation. ====
QAT picture:
* A spherical light wave is a 2-D manifold (the wavefront). The local electromagnetic vector (E) lies in the tangent plane of that sphere. The rotation of that tangent vector around the local propagation axis is the physical content of photon helicity. When a local atom (the electron sphere) absorbs/emits, it couples to the tangential components — transferring one “unit” of angular momentum (spin-1) via the vector character of the boundary coupling.
* So: photon spin ≈ direction/rotation of the tangent E-vector on the 2-D spherical boundary. This directly matches the textbook polarization/helicity picture. Wikipedia<ref>{{cite web|title=Wikipedia|url=https://en.wikipedia.org/wiki/Photon_polarization|publisher=en.wikipedia.org|access-date=2025-12-16}}</ref>

Why this is attractive in QAT: Huygens’ spherical wavefront + tangential EM vectors gives a geometric, area-based support for the two photon helicities.