refraction observations
51Alhazen — For the Moon crater, see Alhazen (crater). For the asteroid, see 59239 Alhazen. Alhazen Alhazen (Ibn al Haytham) …
52Speed of light — The speed of light in the vacuum of free space is an important physical constant usually denoted by the letter c . [NIST and BIPM practice is to use c 0 for the speed of light in vacuum in accord with international standard ISO 31 5. See… …
53Météorologie — La météorologie a pour objet l étude des phénomènes atmosphériques tels que les nuages, les précipitations ou le vent dans le but de comprendre comment ils se forment et évoluent en fonction des paramètres mesurés tels que la pression, la… …
54Ionosphere — The ionosphere is a part of the upper atmosphere, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner …
55Johannes Kepler — Infobox Scientist name = Johannes Kepler |175px image width = 175px caption = A 1610 portrait of Johannes Kepler by an unknown artist birth date = Birth date|1571|12|27 birth place = Weil der Stadt near Stuttgart, Germany residence = Baden… …
56Luminiferous aether — The luminiferous aether: it was hypothesised that the Earth moves through a medium of aether that carries light In the late 19th century, luminiferous aether or ether, meaning light bearing aether, was the term used to describe a medium for the… …
57Dennis Rawlins — Born 1937 (age 73–74) Baltimore, Maryland, United States Nationality American Occupation Astronomer, Historian, Publisher Dennis Rawlins (born 1937 in Baltimore, Maryland) is an American astronomer, historian, and publisher …
58Isaac Newton — Portrait d’Isaac Newton âgé de 46 ans par Godfrey Kneller (1689) Naissance 4 janvier 1643 …
59Sir Isaac Newton — Isaac Newton Isaac Newton Portrait d’Isaac Newton par Godfrey Kneller (1689) Naissance 4 janvier 1643 Woolsthorpe dans le Lincolnshire ( …
60sound — sound1 soundable, adj. /sownd/, n. 1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium. 2. mechanical vibrations transmitted through an elastic medium, traveling in air at a… …
