Re: POLARIZATION

[Leigh Palmer <palmer@sfu.ca>]

> This touches a question in the exam I'm currently marking. Candidates are
> asked to explain why polarization provides evidence for a wave rather than
> a particle theory of light. I'm not too thrilled with the question. Is it
> possible to explain polarization in terms of photons? Spin is the only
> orientable property I can think of.

The photon is moving at the speed of light. Only spin orientations
parallel or antiparallel to the direction of motion are allowed.
These two states are polarized (L and R circularly) and degenerate.
Linear combinations are allowed, and these may have any intermediate
polarization state, including all linear states.

You are correct in disliking the question. It tests no physics
knowledge. It asks for regurgitation of a received factoid. It is
analogous to catechism, and I've tried to avoid teaching
catechism misrepresented as physics.

Leigh