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Cook, Thomas

(Encyclopedia)Cook, Thomas, 1808–92, English travel agent. In Leicester in 1841 he founded a travel agency under his name. The idea of the guided tour met with quick success, and by 1852 Cook had moved his office...

Federal Aviation Administration

(Encyclopedia)Federal Aviation Administration (FAA), component of the U.S. Department of Transportation that sets standards for the air-worthiness of all civilian aircraft, inspects and licenses them, and regulates...

photoelectric effect

(Encyclopedia)photoelectric effect, emission of electrons by substances, especially metals, when light falls on their surfaces. The effect was discovered by H. R. Hertz in 1887. The failure of the classical theory ...

phosphorylation

(Encyclopedia)phosphorylation, chemical process in which a phosphate group is added to an organic molecule. In living cells phosphorylation is associated with respiration, which takes place in the cell's mitochondr...

hydrophone

(Encyclopedia)hydrophone hīˈdrəfōnˌ [key], device that receives underwater sound waves and converts them to electrical energy; the voltage generated can then be read on a meter or played through a loudspeaker....

foot-pound

(Encyclopedia)foot-pound, abbr. ft-lb, unit of work or energy in the customary English gravitational system; it is the work done or energy expended by a force of 1 pound acting through a distance of 1 foot. It is e...

erg

(Encyclopedia)erg ûrg [key], unit of work or energy in the cgs system of units, which is based on the metric system; it is the work done or energy expended by a force of 1 dyne acting through a distance of 1 centi...

phonon

(Encyclopedia)phonon fōˈnŏn [key], quantum of vibrational energy. The atoms of any crystal are in a state of vibration, their average kinetic energy being measured by the absolute temperature of the crystal. In ...