refraction time
71Rainbow — For other uses, see Rainbow (disambiguation). Double rainbow and supernumerary rainbows on the inside of the primary arc. The shadow of the photographer s head on the bottom marks the centre of the rainbow circle (antisolar point). A rainbow is… …
72telescope — /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… …
73Huygens, Christiaan — or Christian Huyghens born April 14, 1629, The Hague died July 8, 1695, The Hague Dutch mathematician, astronomer, and physicist. He was the first to use a pendulum to regulate a clock (1656). He invented a method of grinding and polishing… …
74Birefringence — Displacement of light rays with perpendicular polarization through a birefringent material …
75Science in medieval Islam — In the history of science, Islamic science refers to the science developed under the Islamic civilization between the 8th and 16th centuries, during what is known as the Islamic Golden Age. [cite journal|first=A. I.|last=Sabra|authorlink=A. I.… …
76Radio propagation — is a term used to explain how radio waves behave when they are transmitted, or are propagated from one point on the Earth to another. [ H. P. Westman et al, (ed), Reference Data for Radio Engineers, Fifth Edition , 1968, Howard W. Sams and Co.,… …
77Day length — as a function of latitude and the day of the year Day length, or length of day, or length of daytime, refers to the time each day from the moment the upper limb of the sun s disk appears above the horizon during sunrise to the moment when the… …
78Science and Technology in the Ottoman Empire — covers the topics related to achievements and distinguished events that happened during the existence of the empire. The study of scientific, cultural and intellectual aspects of Ottoman history is a very new area. The culturalist approach that… …
79Dennis 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 …
80Newton, Sir Isaac — born Jan. 4, 1643, Woolsthorpe, Lincolnshire, Eng. died March 31, 1727, London English physicist and mathematician. The son of a yeoman, he was raised by his grandmother. He was educated at Cambridge University (1661–65), where he discovered the… …
