Columbia Encyclopedia

Search results

421 results found

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 ...

Lamb, Willis Eugene, Jr.

(Encyclopedia)Lamb, Willis Eugene, Jr., 1913–2008, American physicist, b. Los Angeles, Ph.D. Univ. of California, Berkeley, 1938. Lamb was a professor at Columbia (1938–51), Stanford (1951–56), Oxford (1956�...

Sakharov, Andrei Dmitriyevich

(Encyclopedia)Sakharov, Andrei Dmitriyevich, 1921–89, Soviet nuclear physicist and human-rights advocate; first Soviet citizen to receive the Nobel Peace Prize (1975). From 1948 to 1956 he helped to develop the U...

Ramsey, Norman Foster, Jr.

(Encyclopedia)Ramsey, Norman Foster, Jr., 1915–2011, American physicist, b. Washington, D.C., Ph.D. Columbia, 1940. A member of the faculty at Harvard from 1947 and the Higgins professor of physics from 1966 (eme...

Andrée, Salomon August

(Encyclopedia)Andrée, Salomon August säˈlo͞omôn ouˈgəst ändrāˈ [key], 1854–97, Swedish polar explorer, grad. Royal Inst. of Technology, Stockholm. An aeronautical engineer and head of the Swedish patent...

‘Oumuamua

(Encyclopedia)‘Oumuamua ōmo͞oˈəmo͞oˈə [key], officially 1I/2017 U1 (‘Oumuamua), interstellar object, the first to be discovered in the solar system. Highly variable in brightness, it also is highly and u...

Freon

(Encyclopedia)Freon frēˈŏn [key] [trade name], any one of a special class of chemical compounds that are used as refrigerants, aerosol propellants, and solvents. These compounds are haloalkanes, i.e., halogen de...

ammonium group

(Encyclopedia)ammonium group, in chemistry, a positively charged nitrogen atom joined by single bonds to four other atoms or groups. The simplest ammonium group, NH4+, is formed by protonation of ammonia, NH3, e.g....

fusion

(Encyclopedia)fusion, in physics. 1 The change of a substance from the solid to the liquid state, also known as melting. The heat given up by a unit mass of a substance during fusion is called the latent heat of fu...

bromide

(Encyclopedia)bromide, any of a group of compounds that contain bromine and a more electropositive element or radical. Bromides are formed by the reaction of bromine or a bromide with another substance; they are wi...