Columbia Encyclopedia
Search results
500 results found
measurement
(Encyclopedia)measurement, determination of the magnitude of a quantity by comparison with a standard for that quantity. Quantities frequently measured include time, length, area, volume, pressure, mass, force, and...dark matter
(Encyclopedia)dark matter, material that is believed to make up nearly 27% of the mass of the universe but is not readily visible because it neither emits nor reflects electromagnetic radiation, such as light or ra...calorimetry
(Encyclopedia)calorimetry kălˌərĭmˈətrē [key], measurement of heat and the determination of heat capacity. Heat is evolved in exothermic processes and absorbed in endothermic processes; such processes includ...neutron
(Encyclopedia)neutron, uncharged elementary particle of slightly greater mass than the proton. It was discovered by James Chadwick in 1932. The stable isotopes of all elements except hydrogen and helium contain a n...Mendeleev, Dmitri Ivanovich
(Encyclopedia)Mendeleev, Dmitri Ivanovich mĕndəlāˈəf, Rus. dəmēˈtrē ēväˈnəvĭch myĭndyĭlyāˈəf [key], 1834–1907, Russian chemist. He is famous for his formulation (1869) of the periodic law and t...Stowe, Calvin Ellis
(Encyclopedia)Stowe, Calvin Ellis stō [key], 1802–86, American educator, b. Natick, Mass., grad. Bowdoin College, 1824, and Andover Theological Seminary, 1828; husband of Harriet Beecher Stowe. He was professor ...Empedocles
(Encyclopedia)Empedocles ĕmpĕdˈəklēz [key], c.495–c.435 b.c., Greek philosopher, b. Acragas (present Agrigento), Sicily. Leader of the democratic faction in his native city, he was offered the crown, which h...Southeast Asian languages
(Encyclopedia)Southeast Asian languages, family of languages, sometimes also called Austroasiatic, spoken in SE Asia by about 80 million people. According to one school of thought, it has three subfamilies: the Mon...quantum theory
(Encyclopedia)quantum theory, modern physical theory concerned with the emission and absorption of energy by matter and with the motion of material particles; the quantum theory and the theory of relativity togethe...gravel
(Encyclopedia)gravel, particles of rock, i.e., stones and pebbles, usually round in form and intermediate in size between sand grains and boulders. Gravel is composed of various kinds of rock, the most common const...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 +-
