Snell's law relates phase velocity to the sines of two of these measures.
A "magic" one of these measures reduces the effect of nuclear spin interactions in NMR spectroscopy. An Ewald ("YOU"-uhld) sphere shows the relationship between wavelength, distance, the unit cell, and this measure of the diffracted X-rays. The value of the reflection coefficient for p-polarized light is (*) zero at one of these measures. Snell's law relates phase velocity to the sines of two of these measures. For 10 points, name these measures, examples of which include a critical one, Brewster's one, and ones "of incidence."
A "magic" one of these measures reduces the effect of nuclear spin interactions in NMR spectroscopy.
{angles} [or magic {angles} before "{cross}-{section}"; or {measure} of the {angle} or synonyms]