How do wave particles have spin?

Question

I am not a student nor a scientist. If a photon is a wave until it is measured somehow, how can it have a spin? A wave is a wave. Is spin simply a mathematical tag that we give to particles? Or do particle waves not have spin until they collapse back into an actual particle?

score 1 · Answer 1 · answered Sep 07 '20 at 14:25

1

The wave field is not just a scalar field. The field value is "spinny". For a spin-0 particle the field has scalar values, but for a spin-1 particle the field has vector values. For a spin-½ particle the field has spinor values.

answered Sep 07 '20 at 14:25

md2perpe

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score 0 · Answer 2 · answered Sep 07 '20 at 14:26

In classical theory, a charge oscillating in one dimension introduces transverse components into its electric field. These move away as part of a linearly polarized electromagnetic wave. If the charge moves in a circle (or ellipse) the electric fields in the wave rotate and can impart angular momentum to a receiving charge.

score -1 · Answer 3 · answered Sep 07 '20 at 12:39

You can ask the same question classically. An electromagnetic wave is fluctuations of the electric force and magnetic force, which point in particular directions. If the directions follow the right-hand-rule, the wave has positive spin. If these directions follow the left-hand-rule, the wave has negative spin.

How do wave particles have spin?

3 Answers3