the world > movement > absence of movement > [noun] > suspense of movement > point or line of rest in oscillating body (2)
(a) (see senses 1a 3); (b) Optics either of two points on the optic axis of a lens or lens system such that the straight line joining one of them…
A point or line of absolute or comparative rest in a standing wave system; a point at which a spherical harmonic or similar periodic function has…