plural of normal mode

A mode of an oscillating system in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The motion described by the normal modes is called resonance.

plural of normal form

The final depth of water in an open channel that is subject to continuous uniform flow

(algebra) A finite, algebraic extension of some field such that if it contains any root of any irreducible polynomial over that base field then it contains all of the roots of that polynomial.

(photography) A lens which produces an image similar in detail and angular perspective to the view produced by the human eye, as distinct from a wide-angle lens or a telephoto lens.

(economics) a good for which demand increases when income increases and falls when income decreases but price remains constant, i.e. with a positive income elasticity of demand.

plural of normal space

(topology) A regular space with the additional property that for every disjoint pair of closed sets in that space, there is a disjoint pair of open sets which contain the closed sets, respectively.

plural of normal subgroup