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radiometer

(Encyclopedia)radiometer rāˌdēŏmˈətər [key], instrument for detection or measurement of electromagnetic radiation; the term is applied in particular to devices used to measure infrared radiation. One of the ...

polytheism

(Encyclopedia)polytheism pŏlˈēthēĭzəm [key], belief in a plurality of gods in which each deity is distinguished by special functions. The gods are particularly synonymous with function in the Vedic religion (...

Peirce, Charles Sanders

(Encyclopedia)Peirce, Charles Sanders pûrs [key], 1839–1914, American philosopher and polymath, b. Cambridge, Mass., grad. Harvard, 1859; son of Benjamin Peirce. Except for occasional lectures he renounced the r...

brake, in technology

(Encyclopedia)CE5 Shoe brake CE5 Disk brake brake, in technology, device to slow or stop the motion of a mechanism or vehicle. The vacuum brake system, or vacuum brake, depends upon the use of a vacuum to ...

cosmology

(Encyclopedia)cosmology, area of science that aims at a comprehensive theory of the structure and evolution of the entire physical universe. The earliest pre-Ptolemaic theories assumed that the earth was the cent...

drill, tool

(Encyclopedia)drill, tool used to create a hole, usually in some hard substance, by its rotary or hammering action. Many different tools make up the drill family. The awl is a pointed instrument used for piercing s...

Darwinism

(Encyclopedia)Darwinism, concept of evolution developed in the mid-19th cent. by Charles Robert Darwin. Darwin's meticulously documented observations led him to question the then current belief in special creation ...

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...

Brown v. Board of Education of Topeka, Kans.

(Encyclopedia)Brown v. Board of Education of Topeka, Kans., case decided by the U.S. Supreme Court in 1954. Linda Brown was denied admission to her local elementary school in Topeka because she was black. When, com...

blast furnace

(Encyclopedia)CE5 Blast furnace for production of iron blast furnace, structure used chiefly in smelting. The principle involved in this means of extracting metals is that of the reduction of the ores by the ac...