spectrum component
41chemical compound — Introduction any substance composed of identical molecules consisting of atoms (atom) of two or more chemical elements (chemical element). All the matter in the universe is composed of the atoms of more than 100 different chemical elements …
42chemical element — Introduction also called element, any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. This article considers the… …
43Active galactic nucleus — An active galactic nucleus (AGN) is a compact region at the centre of a galaxy which has a much higher than normal luminosity over some or all of the electromagnetic spectrum (in the radio, infrared, optical, ultra violet, X ray and/or gamma ray… …
44optics — /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,… …
45eclipse — eclipser, n. /i klips /, n., v., eclipsed, eclipsing. n. 1. Astron. a. the obscuration of the light of the moon by the intervention of the earth between it and the sun (lunar eclipse) or the obscuration of the light of the sun by the intervention …
46human disease — Introduction an impairment of the normal state of a human being that interrupts or modifies its vital functions. health versus disease Before human disease can be discussed, the meanings of the terms health, physical fitness, illness …
47radiation measurement — ▪ technology Introduction technique for detecting the intensity and characteristics of ionizing radiation, such as alpha, beta, and gamma rays or neutrons, for the purpose of measurement. The term ionizing radiation refers to those… …
48Eigenvalues and eigenvectors — For more specific information regarding the eigenvalues and eigenvectors of matrices, see Eigendecomposition of a matrix. In this shear mapping the red arrow changes direction but the blue arrow does not. Therefore the blue arrow is an… …
49Nuclear magnetic resonance — This article is about the physical phenomenon. For its use as a method in spectroscopy, see Nuclear magnetic resonance spectroscopy. NMR redirects here. For other uses, see NMR (disambiguation). First 1 GHz NMR Spectrometer (1000 MHz,… …
50Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
