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Copernican system

(Encyclopedia)Copernican system, first modern European theory of planetary motion that was heliocentric, i.e., that placed the sun motionless at the center of the solar system with all the planets, including the ea...

Piccard, Auguste

(Encyclopedia)Piccard, Auguste ōgüstˈ pēkärˈ [key], 1884–1962, Swiss physicist, b. Basel. He became a professor at the Univ. of Brussels in 1922. He and his twin brother Jean Felix (d. 1963) are known for t...

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...

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 ...

infrared astronomy

(Encyclopedia)infrared astronomy, study of celestial objects by means of the infrared radiation they emit, in the wavelength range from about 1 micrometer to about 1 millimeter. All objects, from trees and building...

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...

exclusion principle

(Encyclopedia)exclusion principle, physical principle enunciated by Wolfgang Pauli in 1925 stating that no two electrons in an atom can occupy the same energy state simultaneously. The energy states, or levels, in ...

Schuster, Sir Arthur

(Encyclopedia)Schuster, Sir Arthur, 1851–1934, English physicist, b. Germany. At Owens College, Manchester Univ., he was professor of applied mathematics (1881–88) and professor of physics (1888–1907). He is ...

Schwabe, Samuel Heinrich

(Encyclopedia)Schwabe, Samuel Heinrich zäˈmo͞oĕl hīnˈrĭkh shväbˈə [key], 1789–1875, German apothecary and amateur astronomer. In the hope of discovering a new planet between Mercury and the sun, he made...