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Cepheid variables
(Encyclopedia)Cepheid variables sēˈfēĭd [key], class of variable stars that brighten and dim in an extremely regular fashion. The periods of the fluctuations (the time to complete one cycle from bright to dim a...variable star
(Encyclopedia)variable star, star that varies, either periodically or irregularly, in the intensity of the light it emits. Other physical changes are usually correlated with the fluctuations in brightness, such as ...Shapley, Harlow
(Encyclopedia)Shapley, Harlow shăpˈlē [key], 1885–1972, American astronomer, b. Nashville, Mo., grad. Univ. of Missouri, 1910, Ph.D. Princeton, 1913. He was astronomer at Mt. Wilson Observatory from 1914 to 19...Baade, Walter
(Encyclopedia)Baade, Walter välˈtər bäˈdə [key], 1893–1960, German-born American astronomer. From 1919 to 1931 he was on the staff of the Hamburg observatory; from 1931 to 1958, at the Mt. Wilson observator...Hubble, Edwin Powell
(Encyclopedia)Hubble, Edwin Powell, 1889–1953, American astronomer, b. Marshfield, Mo. He did research (1914–17) at Yerkes Observatory, and joined (1919) the staff of Mt. Wilson Observatory, Pasadena, Calif., o...calculus of variations
(Encyclopedia)calculus of variations, branch of mathematics concerned with finding maximum or minimum conditions for a relationship between two or more variables that depends not only on the variables themselves, a...linear programming
(Encyclopedia)linear programming, solution of a mathematical problem concerning maximum and minimum values of a first-degree (linear) algebraic expression, with variables subject to certain stated conditions (restr...tensor
(Encyclopedia)tensor, in mathematics, quantity that depends linearly on several vector variables and that varies covariantly with respect to some variables and contravariantly with respect to others when the coordi...equation
(Encyclopedia)equation, in mathematics, a statement, usually written in symbols, that states the equality of two quantities or algebraic expressions, e.g., x+3=5. The quantity x+3, to the left of the equals sign (=...gas laws
(Encyclopedia)gas laws, physical laws describing the behavior of a gas under various conditions of pressure, volume, and temperature. Experimental results indicate that all real gases behave in approximately the sa...Browse by Subject
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