An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Optics: A strip or annulus of material, such as glass or film, whose density increases progressively from one end to the other. The function of the wedge is to weaken the light beam in an optical system.

Verbal adj. from → absorb; → wedge.

A portion of the → space-time described by → Rindler coordinates.

→ Rindler coordinates; → wedge.

A glass prism of very small angle used as an optical element to divert the path of a beam of light for a particular purpose. → absorbing wedge.

M.E. wegge; O.E. wecg "a wedge," cf. M.Du. wegge, Du. wig, O.H.G. weggi "wedge," Ger. Weck "wedge-shaped bread roll."

Gové "wedge;" Av. vada- "wedge," ^xvaδa- "deadly weapon;" cf. Skt. vadhá- "killer, deadly weapon," vadh- "to slay, kill;" Gk. othein "to push" (root of → osmosis).

A photometer in which an → absorbing wedge is inserted in the brighter of two beams until the flux densities of the two light sources are equal.

→ wedge; → photometer.