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photon

(Encyclopedia)photon fōˈtŏn [key], the particle composing light and other forms of electromagnetic radiation, sometimes called light quantum. The photon has no charge and no mass. About the beginning of the 20th...

blackbody

(Encyclopedia)blackbody, in physics, an ideal black substance that absorbs all and reflects none of the radiant energy falling on it. Lampblack, or powdered carbon, which reflects less than 2% of the radiation fall...

ship

(Encyclopedia)ship, large craft in which persons and goods may be conveyed on water. In the U.S. Navy the term boat refers to any vessel that is small enough to be hoisted aboard a ship, and ship is used for any la...

Iran

(Encyclopedia)CE5 Iran ēränˈ, ĭrănˈ [key], officially Islamic Republic of Iran, republic (2015 est. pop. 79,360,000), 636,290 sq mi (1,648,000 sq km), SW Asia. The country's name was changed from Persia to...

Monroeville

(Encyclopedia)Monroeville, borough (1990 pop. 29,169), Allegheny co., SW Pa., a suburb of Pittsburgh; settled 1810, inc. 1952. It is primarily residential, with a major shopping mall. Monroeville has chemical and n...

Ashton, Catherine Margaret, Baroness Ashton of Upholland

(Encyclopedia)Ashton, Catherine Margaret, Baroness Ashton of Upholland, 1956– British government official. She was an administrator for the Campaign for Nuclear Disarmament (1977–83), director of Business in th...

Semipalatinsk Test Site

(Encyclopedia)Semipalatinsk Test Site, Soviet nuclear testing site, c.6,950 sq mi (18,000 sq km), NE Kazakhstan, near the city of Kurchatov and some 90 mi (150 km) W of Semey (formerly Semipalatinsk). Between 1949 ...

Brown, Harold

(Encyclopedia)Brown, Harold, 1927–2019, American nuclear physicist and government official, b. New York City, Ph.D. Columbia, 1949. He joined (1952) the staff of the Lawrence Radiation Laboratory (now Lawrence Li...

rocket, in aeronautics

(Encyclopedia)CE5 Relative positions of the components of the Saturn V rocket, the U.S. space vehicle used in the moon missions rocket, any vehicle propelled by ejection of the gases produced by combustion of s...

solar constant

(Encyclopedia)solar constant, the average amount of radiant energy received by the earth's atmosphere from the sun; its value is about 2 calories per min incident on each square centimeter of the upper atmosphere. ...