Re: [Phys-L] phase of a classical wavefunction

[John Denker <jsd@av8n.com>]

On 01/20/2015 08:04 PM, Carl Mungan wrote:
> One person suggested to me that it makes sense to change the sign of k
> because that's proportional to momentum, whereas it doesn't make sense to
> change the sign of w because that's a frequency. For a complex wave, he
> suggested we like to keep the sign of the exp(iwt) term alone and only
> fiddle with the sign of the exp(ikx) piece.
>
> Do you agree with that suggestion?

In this case, yes, absolutely.  A reflection reverses k.

> Is there another way to look at this situation?

No, but there are other situations where the answer might
be different.  It depends on the physics.  If the physics
is 1D reflection, then k gets reversed.  In higher dimensions,
k gets mirrored, which changes some components of k
differently from others.

More generally, asking about "the phase" isn't the optimal
question, because physical significance attaches to k and ω 
on their own, not just to the combination we call phase.