reflection optical density
121physics — /fiz iks/, n. (used with a sing. v.) the science that deals with matter, energy, motion, and force. [1580 90; see PHYSIC, ICS] * * * I Science that deals with the structure of matter and the interactions between the fundamental constituents of… …
122Mirage of astronomical objects — Mock mirage of the setting sun A mirage of an astronomical object is a naturally occurring optical phenomenon, in which light rays are bent to produce distorted or multiple images of an astronomical object. The mirages might be observed for such… …
123Spectroscopy — Analysis of white light by dispersing it with a prism is example of spectroscopy. Spectroscopy ( …
124Cygnus X-1 — For other uses, see Cygnus X 1 (disambiguation). HDE 226868 HDE 226868 (not shown) is located next to the star η (lower center) in this map of constellation Cygnus …
125Speed of sound — Sound is a vibration that travels through an elastic medium as a wave. The speed of sound describes how much distance such a wave travels in a certain amount of time. In SI Units with dry air at 20 °C (68 °F), the speed of sound is 343 m/s. This… …
126papermaking — [pā′pər māk΄iŋ] n. the making of paper papermaker n. * * * pa·per·mak·ing (pāʹpər mā kĭng) n. The process or craft of making paper. paʹper·mak er n. * * * Introduction formation of a matted or felted sheet, usually of cellulose fibres,… …
127Acoustic microscopy — Introduction = Acoustic microscopes employ very high or ultra high frequency ultrasound. These microscopes operate nondestructively and penetrate most solid materials to make visible images of internal features, including defects such as cracks,… …
128electricity — /i lek tris i tee, ee lek /, n. 1. See electric charge. 2. See electric current. 3. the science dealing with electric charges and currents. 4. a state or feeling of excitement, anticipation, tension, etc. [1640 50; ELECTRIC + ITY] * * *… …
