Mathematics and Physics Glossary

Z-axis, n. (Math.) One of three axes in a three-dimensional Cartesian coördinate system.

Zeeman effect. (Phys.) The widening and duplication, triplication, etc., of spectral lines when the radiations emanate in a strong magnetic field, first observed in 1896 by P. Zeeman, a Dutch physicist, and regarded as an important confirmation of the electromagnetic theory of light.

Zenith distance (Astron.) See under Distance.

Zenith sector (Astron.) See Sector.

Zero, n.; pl. Zeros or Zeroes.

1. (Arith.) A cipher; nothing; naught.

2. (Math.) (a) An element of a set that when added to any other element in the set produces a sum identical with the element to which it is added. (b) A cardinal number indicating the absence of any or all units under consideration. (c) An ordinal number indicating an initial point or origin. (d) An argument at which the value of a function vanishes.

-- Zero exponent, n. (Math.) An exponent which is equal to zero; any number, except zero, raised to a zero exponent is equal to 1.