emission+of+rays
71Corona — This article is about the astronomical term. For other uses, see Corona (disambiguation). During a total solar eclipse, the solar corona can be seen with the naked eye. A corona is a type of plasma atmosphere of the Sun or other celestial body,… …
72Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …
73Bremsstrahlung — produced by a high energy electron deflected in the electric field of an atomic nucleus Bremsstrahlung (German pronunciation: [ˈbʁɛmsˌʃtʁaːlʊŋ] ( …
74photoelectric effect — Physics. the phenomenon in which the absorption of electromagnetic radiation, as light, of sufficiently high frequency by a surface, usually metallic, induces the emission of electrons from the surface. Also called photoemission. [1890 95] * * *… …
75radioactivity — /ray dee oh ak tiv i tee/, n. Physics, Chem. the phenomenon, exhibited by and being a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element. Also called activity. [1895… …
76Beta decay — Nuclear physics Radioactive decay Nuclear fission Nuclear fusion Classical decays …
77microscope — /muy kreuh skohp /, n. 1. an optical instrument having a magnifying lens or a combination of lenses for inspecting objects too small to be seen or too small to be seen distinctly and in detail by the unaided eye. 2. (cap.) Astron. the… …
78telescope — /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… …
79Supernova remnant — Multiwavelength composite image of the remnant of Kepler s supernova, SN 1604 …
80Messier 87 — Virgo A The Messier 87 galaxy. Observation data Epoch J2000 Constellation Virgo Right ascension …