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dwarf planet

(Encyclopedia)dwarf planet, a nonluminous body of rock or gas that orbits the sun and has a rounded shape due to its gravity. Unlike a planet, a dwarf planet is not capable of clearing its orbit of smaller objects ...

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...

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...

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 ...

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...

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...

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...

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 ...