prism


prism
/priz"euhm/, n.
1. Optics. a transparent solid body, often having triangular bases, used for dispersing light into a spectrum or for reflecting rays of light.
2. Geom. a solid having bases or ends that are parallel, congruent polygons and sides that are parallelograms.
3. Crystall. a form having faces parallel to the vertical axis and intersecting the horizontal axes.
[1560-70; < LL prisma < Gk prîsma lit., something sawed, akin to prízein to saw, pristes sawyer]

* * *

Piece of glass or other transparent material cut with precise angles and plane faces.

Prisms are useful for analyzing and refracting light (see refraction). A triangular prism can separate white light into its constituent colours by refracting each different wavelength of light by a different amount. The longer wavelengths (those at the red end of the spectrum) are bent the least, the shorter ones (those at the violet end) the most. The result is the spectrum of visible light, or the rainbow. Prisms are used in certain kinds of spectroscopy and in various optical systems.

* * *

optics
 in optics, piece of glass or other transparent material cut with precise angles and plane faces, useful for analyzing and reflecting light. An ordinary triangular prism can separate white light into its constituent colours, called a spectrum (see illustration—>, left). Each colour, or wavelength, making up the white light is bent, or refracted, a different amount; the shorter wavelengths (those toward the violet end of the spectrum) are bent the most, and the longer wavelengths (those toward the red end of the spectrum) are bent the least. Prisms of this kind are used in certain spectroscopes, instruments for analyzing light and for determining the identity and structure of materials that emit or absorb light.

 Prisms can reverse the direction of light by internal reflection (see illustration—>, right), and for this purpose they are useful in binoculars (q.v.).

      Prisms are made in many different forms and shapes, depending on the application. The Porro prism, for example, consists of two prisms arranged both to invert and to reverse an image and are used in many optical viewing instruments, such as periscopes, binoculars, and monoculars. The Nicol prism consists of two specially cut calcite prisms bonded together with an adhesive known as Canada balsam. This prism transmits waves vibrating in one direction only and thus produces a plane-polarized beam from ordinary light.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Prism — may refer to:cience and mathematics* Prism (optics), a transparent object which refracts light ** Dispersive prism, the most familiar type of optical prism * Prism (geometry), a kind of polyhedron * Prism (geology), a kind of sedimentary… …   Wikipedia

  • PRISM — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. PRISM peut faire référence à : PRISM, un concours d accès à l ISEG, une grande école de commerce, PRISM, une planète fictive introduite par Alan Dean …   Wikipédia en Français

  • Prism — (pr[i^]z m), n. [L. prisma, Gr. pri sma, fr. pri zein, pri ein, to saw: cf. F. prisme.] 1. (Geom.) A solid whose bases or ends are any similar, equal, and parallel plane figures, and whose sides are parallelograms. [1913 Webster] Note: Prisms of… …   The Collaborative International Dictionary of English

  • Prism — steht für: Delphi Prism, Delphi Programmierumgebung für das .NET Framework, siehe Embarcadero Delphi#Delphi Prism (Delphi .NET) Mozilla Prism, freie Softwareumgebung, um Webanwendungen in eine Desktopumgebung zu integrieren Prism (Rockband) oder… …   Deutsch Wikipedia

  • PRISM — может означать: PRISM (микросхема), микросхема, выпущенная компанией Conexant, обеспечивающая беспроводную связь DEC PRISM, английская аббревиатура от «Параллельный вычислитель с ограниченным набором команд» компании Digital Equipment Corporation …   Википедия

  • Prism 3D — Le Prism 3D est un cerf volant adapté au vol en intérieur ou en extérieur par vent nul à léger. Sa voilure est de type delta, et il se pilote au moyen de deux lignes …   Wikipédia en Français

  • prism — [ prızəm ] noun count any solid object that has a regular shape with flat sides and straight edges, especially an object with some sides shaped like a TRIANGLE a. a glass object in the shape of a prism, used for dividing light into its different… …   Usage of the words and phrases in modern English

  • prism — 1560s, a type of solid figure, from L.L. prisma (Martianus Capella), from Gk. prisma (Euclid), lit. something sawed, from prizein to saw. Meaning in optics is first attested 1610s …   Etymology dictionary

  • prism — ► NOUN 1) a piece of glass or other transparent material of regular shape, used to separate white light into a spectrum of colours. 2) Geometry a solid geometric figure whose two ends are similar, equal, and parallel rectilinear figures, and… …   English terms dictionary

  • prism — [priz′əm] n. [LL prisma < Gr, lit., something sawed < prizein, to saw < priein, to saw, bite; ? akin to Alb prish, (I) destroy, break] 1. Geom. a solid figure whose ends are parallel, polygonal, and equal in size and shape, and whose… …   English World dictionary

  • Prism — Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. PRISM peut faire référence à : PRISM, un concours d accès à l ISEG, une grande école de commerce, PRISM, une planète fictive introduite par Alan Dean …   Wikipédia en Français


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.