Differences in this quantity are approximated in the Fraunhofer and Fresnel conditions to first and second order respectively in the aperture coordinates.
Differences in this quantity are approximated in the Fraunhofer and Fresnel conditions to first and second order respectively in the aperture coordinates. Noether's theorem states that global invariance of this quantity gives rise to conservation of charge. In double slit diffraction, peaks and troughs are caused by differences in (*) path length, which in turn creates differences in this quantity. Coherence occurs when differences in this quantity are constant. Two waves are identical if they have the same value for amplitude, frequency, and this quantity, which is a constant additive factor inside the sinusoidal function. For 10 points, name this quantity which also names a velocity contrasted with group velocity.
Differences in this quantity are approximated in the Fraunhofer and Fresnel conditions to first and second order respectively in the aperture coordinates.
phase [accept gauge; accept path length before "conservation of charge," prompt afterwards]