Phases
Phase Phase (f[=a]z), n.; pl. {Phases} (f[=a]z"[e^]z). [NL. phasis, Gr. ?, fr. ? to make to appear: cf. F. phase. See {Phenomenon}, {Phantom}, and {Emphasis}.] 1. That which is exhibited to the eye; the appearance which anything manifests, especially any one among different and varying appearances of the same object. [1913 Webster]

2. Any appearance or aspect of an object of mental apprehension or view; as, the problem has many phases. [1913 Webster]

3. (Astron.) A particular appearance or state in a regularly recurring cycle of changes with respect to quantity of illumination or form of enlightened disk; as, the phases of the moon or planets. See Illust. under {Moon}. [1913 Webster]

4. (Physics) Any one point or portion in a recurring series of changes, as in the changes of motion of one of the particles constituting a wave or vibration; one portion of a series of such changes, in distinction from a contrasted portion, as the portion on one side of a position of equilibrium, in contrast with that on the opposite side. [1913 Webster]

5. (Phys. Chem.) A homogenous, physically distinct portion of matter in a system not homogeneous; as, the three phases, ice, water, and aqueous vapor. A phase may be either a single chemical substance or a mixture, as of gases. [Webster 1913 Suppl.]

6. (Zo["o]l.) In certain birds and mammals, one of two or more color variations characteristic of the species, but independent of the ordinary seasonal and sexual differences, and often also of age. Some of the herons which appear in white and colored phases, and certain squirrels which are sometimes uniformly blackish instead of the usual coloration, furnish examples. Color phases occur also in other animals, notably in butterflies. [Webster 1913 Suppl.]

7. (Elec.) The relation at any instant of a periodically varying electric magnitude, as electro-motive force, a current, etc., to its initial value as expressed in factorial parts of the complete cycle. It is usually expressed in angular measure, the cycle beb four right angles, or 360[deg]. Such periodic variations are generally well represented by sine curves; and phase relations are shown by the relative positions of the crests and hollows of such curves. Magnitudes which have the same phase are said to be in phase. [Webster 1913 Suppl.]

8. (Physics) the relation at any instant of any cyclically varying physical quantity, such as voltage in an A.C. circuit, an electromagnetic wave, a sound wave, or a rotating object, to its initial value as expressed as a fractional part of the complete cycle. It is usually expressed in angular measure, the complete cycle being 360[deg].

Note: The concept of phase is also applied generally to any periodically varying phenomenon, as the cycle of daylight. One person who speeps during the day and another who sleeps at noght may be said to be out of phase with each other. [PJC]


The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

  • Phases — Phase Cette page d’homonymie répertorie les différents sujets et articles partageant un même nom. Le mot phase désigne l état d un phénomène, variable voire cyclique, à un instant donné. Le terme fait partie du jargon de plusieurs sciences  …   Wikipédia en Français

  • Phases — Phasis Pha sis, n.; pl. {Phases}. [NL.] See {Phase}. Creech. [1913 Webster] …   The Collaborative International Dictionary of English

  • phases — feɪz n. stage; side, angle, aspect; period v. plan in stages, plan in gradual steps …   English contemporary dictionary

  • phases — shapes …   Anagrams dictionary

  • phases — plural of phase present third singular of phase …   Useful english dictionary

  • Phases de Vénus — et évolution de son diamètre apparent. Les phases de la planète Vénus sont les variations de la partie éclairée de sa surface visible depuis la Terre, similaires aux phases de la Lune. Les premières traces écrites de leur observation datent de… …   Wikipédia en Français

  • PHASES (astronomie) — PHASES, astronomie Apparences lumineuses diverses sous lesquelles se présentent successivement les corps célestes éclairés par un astre (le Soleil dans le cas du système solaire). Les phases de la Lune sont les plus remarquables. Si L et l sont… …   Encyclopédie Universelle

  • Phases (mouvement artistique) — Pour les articles homonymes, voir Phase. Le mouvement Phases, ou Phases convertisseur d’énergie, est un mouvement de réflexion et d’expression artistique né dans les années 1950 en France et mené par un groupe élargi de peintres, poètes et… …   Wikipédia en Français

  • Phases de la Lune — Phase lunaire En astronomie, une phase lunaire désigne une portion de Lune illuminée par le Soleil et vue à partir de la Terre. La Lune tournant en orbite autour de la Terre, les positions relatives du Soleil, de la Terre et de la Lune changent… …   Wikipédia en Français

  • Phases de la lune — Phase lunaire En astronomie, une phase lunaire désigne une portion de Lune illuminée par le Soleil et vue à partir de la Terre. La Lune tournant en orbite autour de la Terre, les positions relatives du Soleil, de la Terre et de la Lune changent… …   Wikipédia en Français

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