Columbia Encyclopedia
Search results
500 results found
Doppler effect
(Encyclopedia)Doppler effect, change in the wavelength (or frequency) of energy in the form of waves, e.g., sound or light, as a result of motion of either the source or the receiver of the waves; the effect is nam...Debye, Peter Joseph Wilhelm
(Encyclopedia)Debye, Peter Joseph Wilhelm dēbīˈ [key], 1884–1966, American physicist, b. the Netherlands. He was professor at the universities of Zürich, Utrecht, Göttingen, Leipzig, and Berlin. In 1940 he c...Westinghouse, George
(Encyclopedia)Westinghouse, George, 1846–1914, American inventor and manufacturer, b. Central Bridge, N.Y. In the Civil War he served in the Union army and navy. Among his inventions in the railroad field were a ...impedance
(Encyclopedia)impedance, in electricity, measure in ohms of the degree to which an electric circuit resists the flow of electric current when a voltage is impressed across its terminals. Impedance is expressed as t...Lenz's law
(Encyclopedia)Lenz's law, physical law, discovered by the German scientist H. F. E. Lenz in 1834, that states that the electromotive force (emf) induced in a conductor moving perpendicular to a magnetic field tends...nationalization
(Encyclopedia)nationalization, acquisition and operation by a country of business enterprises formerly owned and operated by private individuals or corporations. State or local authorities have traditionally taken ...elastomer
(Encyclopedia)elastomer ĭlăsˈtəmər [key], substance having to some extent the elastic properties of natural rubber. The term is sometimes used technically to distinguish synthetic rubbers and rubberlike plasti...ratchet and pawl
(Encyclopedia)ratchet and pawl, mechanical device that permits motion in one direction only. The ratchet is usually a wheel with slanting teeth. The pawl is a lever tangential to the wheel with one end resting on t...biodiesel
(Encyclopedia)biodiesel, fuel made from natural, renewable sources, such as new and used vegetable oils and animal fats, for use in a diesel engine. Biodiesel has physical properties very similar to petroleum-deriv...transition elements
(Encyclopedia)transition elements or transition metals, in chemistry, group of elements characterized by the filling of an inner d electron orbital as atomic number increases. This includes the elements from titani...Browse by Subject
- Earth and the Environment +-
- History +-
- Literature and the Arts +-
- Medicine +-
- People +-
- Philosophy and Religion +-
-
Places
+-
- Africa
- Asia
- Australia and Oceania
- Britain, Ireland, France, and the Low Countries
- Commonwealth of Independent States and the Baltic Nations
- Germany, Scandinavia, and Central Europe
- Latin America and the Caribbean
- Oceans, Continents, and Polar Regions
- Spain, Portugal, Italy, Greece, and the Balkans
- United States, Canada, and Greenland
- Plants and Animals +-
- Science and Technology +-
- Social Sciences and the Law +-
- Sports and Everyday Life +-
