| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024par•al•lax (par′ə laks′),USA pronunciation n. - Opticsthe apparent displacement of an observed object due to a change in the position of the observer.
- Astronomythe apparent angular displacement of a celestial body due to its being observed from the surface instead of from the center of the earth (diurnal parallax or geocentric parallax) or due to its being observed from the earth instead of from the sun (annual parallax or heliocentric parallax.) Cf. parallactic ellipse.
- Photographythe difference between the view of an object as seen through the picture-taking lens of a camera and the view as seen through a separate viewfinder.
- Opticsan apparent change in the position of cross hairs as viewed through a telescope, when the focusing is imperfect.
- Greek parállaxis change, equivalent. to parallak- (stem of parallássein to cause to alternate, equivalent. to para- para-1 + allássein to vary, akin to állos other; see else, allo-) + -sis -sis
- 1585–95;
Collins Concise English Dictionary © HarperCollins Publishers:: parallax /ˈpærəˌlæks/ n - an apparent change in the position of an object resulting from a change in position of the observer
- 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
Etymology: 17th Century: via French from New Latin parallaxis, from Greek: change, from parallassein to change, from para-1 + allassein to alterparallactic /ˌpærəˈlæktɪk/ adj |