Fresnel explained diffraction by postulating that mutual interference occurs in secondary wavelets of this construction.
In Space-Time Approach to Non-Relativistic Quantum Mechanics, Feynman expresses this principle as the Chapman-Kolmogorov equation. An essential monograph on this principle is Baker and Copson's The Mathematical Theory of [this principle]. The first Rayleigh-Sommerfeld formula is a common mathematical statement of this principle. This principle is the reason one uses the Green's function e to the j k r over r when deriving Kirchhoff's integral theorem, to which it can be seen as an approximation. It assigns an (*) inclination, or obliquity, factor, so that waves have zero amplitude in the backwards direction. Fresnel explained diffraction by postulating that mutual interference occurs in secondary wavelets of this construction. For 10 points, name this principle which states that every point on a wave-front can be considered a source of secondary spherical wavelets.
In Space-Time Approach to Non-Relativistic Quantum Mechanics, Feynman expresses this principle as the Chapman-Kolmogorov equation.
Huygens's principle [or: Huygens-Fresnel principle]