CDs and DVDs have rainbow reflections because the “parallel” (parallel on the scale of the wavelength of light) rows of pits create a diffraction grating.
The rings in the picture are Newton’s Rings, as pointed out in comments. There are a different set of rings for each wavelength of light and since they don’t all line up you get this rainbow effect.
It’s called
moiré, a form of interference pattern: ~~https://en.wikipedia.org/wiki/Moiré_pattern~~Edit: not moirè, but rather a form of diffraction grating interference because of the minute differences in distance between the two surfaces.
It is also the why DVDs and CDs have rainbow reflections.
CDs and DVDs have rainbow reflections because the “parallel” (parallel on the scale of the wavelength of light) rows of pits create a diffraction grating.
The rings in the picture are Newton’s Rings, as pointed out in comments. There are a different set of rings for each wavelength of light and since they don’t all line up you get this rainbow effect.