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Clausius, Rudolf Julius Emanuel

(Encyclopedia)Clausius, Rudolf Julius Emanuel ro͞oˈdôlf yo͞oˈlyo͝os āmäˈno͞oĕl klouˈzēo͝os [key], 1822–88, German mathematical physicist. A pioneer in the science of thermodynamics, he introduced th...

autotroph

(Encyclopedia)autotroph ôtˈətrōfˌ [key], in biology, an organism capable of synthesizing its own organic substances from inorganic compounds. Autotrophs produce their own sugars, lipids, and amino acids using ...

physics

(Encyclopedia)physics, branch of science traditionally defined as the study of matter, energy, and the relation between them; it was called natural philosophy until the late 19th cent. and is still known by this na...

joule

(Encyclopedia)joule jo͞ol, joul [key], abbr. J, unit of work or energy in the mks system of units, which is based on the metric system; it is the work done or energy expended by a force of 1 newton acting through ...

solar cell

(Encyclopedia)solar cell, semiconductor devised to convert light to electric current. It is a specially constructed diode, usually made of forms of crystalline silicon or of thin films (as of copper indium gallium ...

Joule, James Prescott

(Encyclopedia)Joule, James Prescott jo͞ol, joul [key], 1818–89, English physicist. His scientific researches began in his youth when he invented an electromagnetic engine. Joule made valuable contributions to th...

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...

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...

ecology

(Encyclopedia)ecology, study of the relationships of organisms to their physical environment and to one another. The study of an individual organism or a single species is termed autecology; the study of groups of ...

laser

(Encyclopedia)CE5 Ordinary light sources produce incoherent light, while a laser produces a beam of coherent light. laser [acronym for light amplification by stimulated emission of radiation], device for the cr...