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Kepler's laws

(Encyclopedia)CE5 Schematic representation of Kepler's second law: The areas ABF and A′B′F′ are equal and are swept out in equal intervals of time by a planet orbiting around the sun (at F). Kepler's laws...

Hays, Will H.

(Encyclopedia)Hays, Will H., 1879–1954, American politician and motion-picture executive, b. Sullivan, Ind.; his original name was William Harrison Hays. Hays became active in Indiana political affairs, was chair...

field, in physics

(Encyclopedia)field, in physics, region throughout which a force may be exerted; examples are the gravitational, electric, and magnetic fields that surround, respectively, masses, electric charges, and magnets. The...

Muybridge, Eadweard

(Encyclopedia)Muybridge, Eadweard ĕdˈwərd mīˈbrĭj [key], 1830–1904, English-born photographer and student of animal locomotion. Muybridge changed his name from Edward James Muggeridge. A gifted and obsessed...

binary star

(Encyclopedia)CE5 A. Eclipsing binary: Primary component passing behind secondary (dimmer) component B. Light curve for eclipsing binary binary star or binary system, pair of stars that are held together by the...

fluid mechanics

(Encyclopedia)fluid mechanics, branch of mechanics dealing with the properties and behavior of fluids, i.e., liquids and gases. Because of their ability to flow, liquids and gases have many properties in common not...

Ptolemaic system

(Encyclopedia)Ptolemaic system tŏlˌəmāˈĭk [key], historically the most influential of the geocentric cosmological theories, i.e., theories that placed the earth motionless at the center of the universe with a...

rotary engine

(Encyclopedia)rotary engine, internal-combustion engine whose cycle is similar to that of a piston engine, but which produces rotary motion directly without any conversion from reciprocating motion. A major problem...

centripetal force and centrifugal force

(Encyclopedia)CE5 Centripetal and centrifugal forces: When a ball is swung in a circle at the end of a string, centripetal and centrifugal forces act as shown above. centripetal force and centrifugal force, act...

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