Seattle
Valued Senior Member
Do you consider the same effect in the form of a rainbow to be a cheap parlour trick or the same effect when light passes though a glass of water?To put it bluntly , a cheap parlour trick that means absolutely nothing.
I believe it is the angle having a distance and time displacement effect on the light, and the angle simply stretches the light to is propagation wavelength.
Do you understand the concept of a diffractive index for the various wave lengths present in the colors of the rainbow (the color spectrum)?