emit+rays
81astronomy — /euh stron euh mee/, n. the science that deals with the material universe beyond the earth s atmosphere. [1175 1225; ME astronomie ( < AF) < L astronomia < Gk. See ASTRO , NOMY] * * * I Science dealing with the origin, evolution, composition,… …
82Crookes tube — A Crookes tube. The electrons travel in straight lines from the cathode on the left, shown by the shadow cast by the cross on the fluorescence on the righthand wall. The anode is at the bottom. A Crookes tube is an early experimental electrical… …
83Laser — For other uses, see Laser (disambiguation). United States Air Force laser experiment …
84Optics — For the book by Sir Isaac Newton, see Opticks. Optical redirects here. For the musical artist, see Optical (artist). Optics includes study of dispersion of light. Optics is the branch of …
85subatomic particle — or elementary particle Any of various self contained units of matter or energy. Discovery of the electron in 1897 and of the atomic nucleus in 1911 established that the atom is actually a composite of a cloud of electrons surrounding a tiny but… …
86Electromagnetic spectrum — The electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation frequencies. [cite web|url=http://imagine.gsfc.nasa.gov/docs/dict ei.html#em spectrum|title=Imagine the Universe! Dictionary] The electromagnetic spectrum… …
87Light — For other uses, see Light (disambiguation). Visible light redirects here. For other uses, see Visible light (disambiguation) …
88Brown dwarf — Brown dwarfs are sub stellar objects which are too low in mass to sustain hydrogen 1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no… …
89Atom — The atom is the smallest unit of an element that retains the chemical properties of that element. An atom has an electron cloud consisting of negatively charged electrons surrounding a dense nucleus. The nucleus contains positively charged… …
90analysis — /euh nal euh sis/, n., pl. analyses / seez /. 1. the separating of any material or abstract entity into its constituent elements (opposed to synthesis). 2. this process as a method of studying the nature of something or of determining its… …
