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Manhattan Project

(Encyclopedia)Manhattan Project, the wartime effort to design and build the first nuclear weapons (atomic bombs). With the discovery of fission in 1939, it became clear to scientists that certain radioactive materi...

temperature

(Encyclopedia)CE5 Temperature scales temperature, measure of the relative warmth or coolness of an object. Temperature is measured by means of a thermometer or other instrument having a scale calibrated in unit...

conservation of natural resources

(Encyclopedia)conservation of natural resources, the wise use of the earth's resources by humanity. The term conservation came into use in the late 19th cent. and referred to the management, mainly for economic rea...

molecular weight

(Encyclopedia)molecular weight, weight of a molecule of a substance expressed in atomic mass units (amu). The molecular weight may be calculated from the molecular formula of the substance; it is the sum of the ato...

magnetic resonance

(Encyclopedia)magnetic resonance, in physics and chemistry, phenomenon produced by simultaneously applying a steady magnetic field and electromagnetic radiation (usually radio waves) to a sample of atoms and then a...

cleavage

(Encyclopedia)cleavage, tendency of many minerals to split along definite smooth planar surfaces determined by their crystal structure. The directions of these surfaces are related to weaknesses in the atomic struc...

Halden

(Encyclopedia)Halden hälˈdən [key], town, Østfold co., SE Norway, a port on the Iddefjord (an arm of th...

Mottelson, Benjamin Roy

(Encyclopedia)Mottelson, Benjamin Roy, 1926–, Danish physicist, b. Chicago, Ph.D. Harvard, 1950. Raised and educated in the United States, he moved to Denmark, where he began work as a nuclear physicist. Mottelso...

MacVeagh, Isaac Wayne

(Encyclopedia)MacVeagh, Isaac Wayne məkvāˈ [key], 1833–1917, American political figure, U.S. Attorney General (1881), b. Chester co., Pa. A lawyer, he was the son-in-law of Simon Cameron, Republican boss of Pe...

Keating, Charles Humphrey, Jr.

(Encyclopedia)Keating, Charles Humphrey, Jr., 1923–2014, American banker, b. Cincinnati, grad. Univ. of Cincinnati College of Law (1948). Keating was a partner (1952–72) in a law firm he founded with his brothe...