Columbia Encyclopedia

Search results

500 results found

stellar structure

(Encyclopedia)stellar structure, physical properties of a star and the processes taking place within it. Except for that of the sun, astronomers must draw their conclusions regarding stellar structure on the basis ...

chemosynthesis

(Encyclopedia)chemosynthesis, process in which carbohydrates are manufactured from carbon dioxide and water using chemical nutrients as the energy source, rather than the sunlight used for energy in photosynthesis....

McNaughton, Andrew George Latta

(Encyclopedia)McNaughton, Andrew George Latta məknôtˈən [key], 1887–1966, Canadian general, b. Saskatchewan. An artillery officer in World War I, he was later (1929–35) Canadian chief of staff. In World War...

perpetual-motion machine

(Encyclopedia)perpetual-motion machine, device that would be able to operate continuously and supply useful work, in violation of the laws of thermodynamics. A machine that would produce more energy in the form of ...

Cockcroft, Sir John Douglas

(Encyclopedia)Cockcroft, Sir John Douglas, 1897–1967, English physicist, educated at the Univ. of Manchester and St. John's College, Cambridge. He was a fellow of St. John's College (1928–46) and professor of n...

nucleus, in physics

(Encyclopedia)nucleus, in physics, the extremely dense central core of an atom. Following the discovery of radioactivity by A. H. Becquerel in 1896, Ernest Rutherford identified two types of radiation given off b...

voltaic cell

(Encyclopedia)voltaic cell, a simple device with which chemical energy is converted into electrical energy. Two dissimilar metals (e.g., copper and zinc) are immersed in an electrolyte (e.g., a dissolved sulfate). ...

Baruch, Bernard Mannes

(Encyclopedia)Baruch, Bernard Mannes bəro͞okˈ [key], 1870–1965, U.S. financier and government adviser, b. Camden, S.C. He grew rich through stockmarket speculation before he was 30. In World War I he advised o...

breakwater

(Encyclopedia)breakwater, offshore structure to protect a harbor from wave energy or deflect currents. When it also serves as a pier, it is called a quay; when covered by a roadway it is called a mole. In the Unite...

matter

(Encyclopedia)matter, anything that has mass and occupies space. Matter is sometimes called koinomatter (Gr. koinos=common) to distinguish it from antimatter, or matter composed of antiparticles. The atomic th...