par·al·lax (p r  -lks )n. An apparent change in the direction of an object, caused by a change in observational position that provides a new line of sight. [French parallaxe, from Greek parallaxis, from parallassein, to change : para-, among; see para-1 + allassein, to exchange (from allos, other; see al-1 in Indo-European roots).] par al·lactic (-lkt k) adj. |   The apparent position of a star among more distant stars changes when viewed from opposite sides of the earth's orbit. |
parallax [ˈpærəˌlæks]
n
1. (Physics / General Physics) an apparent change in the position of an object resulting from a change in position of the observer
2. (Astronomy) Astronomy the angle subtended at a celestial body, esp a star, by the radius of the earth's orbit. Annual or heliocentric parallax is the apparent displacement of a nearby star resulting from its observation from the earth. Diurnal or geocentric parallax results from the observation of a planet, the sun, or the moon from the surface of the earth
[via French from New Latin parallaxis, from Greek: change, from parallassein to change, from para-1 + allassein to alter]
parallactic [ˌpærəˈlæktɪk] adj
parallactically adv
| parallax (pr-lks) An apparent shift in the position of an object, such as a star, caused by a change in the observer's position that provides a new line of sight. The parallax of nearby stars caused by observing them from opposite points in Earth's orbit around the Sun is used in estimating the stars' distance from Earth through triangulation. |  Viewed from point A, a nearby star appears to occupy position a against a background of more distant stars. Six months later, from point B, the star appears to occupy position b. |
In photography, the apparent displacement of the position of an object in relation to a reference point, due to a change in the point of observation.
ThesaurusLegend: Synonyms Related Words Antonyms
| Noun | 1. |  parallax - the apparent displacement of an object as seen from two different points that are not on a line with the objectoptical phenomenon - a physical phenomenon related to or involving light annual parallax, heliocentric parallax - the parallax of a celestial body using two points in the earth's orbit around the sun as the baseline diurnal parallax, geocentric parallax - the parallax of a celestial body using two points on the surface of the earth as the earth rotates |
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