Hey...hey, that's a bit too on-topic, don't you think?

Doppler Effect is light as well, that's why it pertains to the red shift of the expanding Universe.

But even if you could detect such a shift in a rotating wheel, presumably it would only affect the color of the bits moving toward you and away. But since you don't see a red shift in the color of a train or jet as it races by & away, this can't be applicable. Though theoretically, I would think there must be some infinitesimally small amount of physical red shifting. There, back off-topic. I knew I could do it.

RBG