concave plane
21Compass plane — Compass Com pass (k[u^]m pas), n. [F. compas, fr. LL. compassus circle, prop., a stepping together; com + passus pace, step. See {Pace}, {Pass}.] 1. A passing round; circuit; circuitous course. [1913 Webster] They fetched a compass of seven day s …
22plano-concave — pla•no con•cave [[t]ˌpleɪ noʊ kɒnˈkeɪv, ˈkɒn keɪv[/t]] adj. opt pertaining to or noting a lens that is plane on one side and concave on the other • Etymology: 1685–95 …
23plano-concave — /pleɪnoʊ ˈkɒnkeɪv/ (say playnoh konkayv) adjective (of lenses) plane on one side and concave on the other …
24compass plane — /ˈkʌmpəs pleɪn/ (say kumpuhs playn) noun a plane, usually of metal, capable of adjustment to convex or concave curves and used for smoothing curved timbers …
25Mach number — (mathrm{Ma} or M) (generally pronEng|ˈmɑːk, sometimes IPA|/ˈmɑːx/ or IPA|/ˈmæk/) is the speed of an object moving through air, or any fluid substance, divided by the speed of sound as it is in that substance. It is commonly used to represent an… …
26optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …
27Cartesian coordinate system — Illustration of a Cartesian coordinate plane. Four points are marked and labeled with their coordinates: (2, 3) in green, (−3, 1) in red, (−1.5, −2.5) in blue, and the origin (0, 0) in purple. A Cartesian coordinate system specifies each point… …
28Lens (optics) — For other uses, see Lens. A lens. Lenses can be used to focus light. A lens is an optical device with perfect or approximate axial symmetry which tra …
29telescope — /tel euh skohp /, n., adj., v., telescoped, telescoping. n. 1. an optical instrument for making distant objects appear larger and therefore nearer. One of the two principal forms (refracting telescope) consists essentially of an objective lens… …
30Eyepiece — For the device for looking through a camera, see viewfinder. A collection of different types of eyepieces. An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is… …
