|
Claude Louis Berthollet, Comte
Claude Louis Berthollet, Comte , 1748-1822, French chemist. His contributions to chemistry include the analysis of ammonia and prussic acid and the discovery of the bleaching properties of chlorine. He collaborated with Antoine Lavoisier in his researches and in reforming chemical nomenclature and s...
Read more
|
|
archaeology
archaeology [Gr.,=study of beginnings], a branch of anthropology that seeks to document and explain continuity and change and similarities and differences among human cultures. Archaeologists work with the material remains of cultures, past and present, providing the only source of information av...
Read more
|
|
mathematics
mathematics deductive study of numbers, geometry, and various abstract constructs, or structures; the latter often "abstract" the features common to several models derived from the empirical, or applied, sciences, although many emerge from purely mathematical or logical considerations. Mathemat...
Read more
|
|
symbolic logic
symbolic logic or mathematical logic, formalized system of deductive logic, employing abstract symbols for the various aspects of natural language. Symbolic logic draws on the concepts and techniques of mathematics, notably set theory, and in turn has contributed to the development of the fou...
Read more
|
|
|
McDonald Observatory
McDonald Observatory astronomical observatory located on Mt. Locke, near Fort Davis, Tex.; founded in 1932, sponsored by the Univ. of Texas in cooperation with the Univ. of Chicago. Its equipment includes 107-in. (272-cm), 82-in. (208-cm), 32-in. (81-cm), and 30-in. (76-cm) reflecting telescopes. T...
Read more
|
|
resistance
resistance property of an electric conductor by which it opposes a flow of electricity and dissipates electrical energy away from the circuit, usually as heat. Optimum resistance is provided by a conductor that is long, small in cross section, and of a material that conducts poorly. Resistance is b...
Read more
|
|
X ray
X ray invisible, highly penetrating electromagnetic radiation of much shorter wavelength (higher frequency) than visible light. The wavelength range for X rays is from about 10 -8 m to about 10 -11 m, or from less than a billionth of an inch to less than a trillionth of an inch; the correspondi...
Read more
|
|
Sir William Crookes
Sir William Crookes 1832-1919, English chemist and physicist. After serving at the Radcliffe Observatory, Oxford, and teaching chemistry at Chester Training College, he retired to work in his own laboratory in London. He discovered the element thallium and made special studies of radioactive substa...
Read more
|
|
|
Sir William Rowan Hamilton
Sir William Rowan Hamilton 1805-65, Irish mathematician and astronomer, b. Dublin. A child prodigy, he had mastered 13 languages by the age of 13 and was still an undergraduate when he became professor of astronomy at the Univ. of Dublin (1827). Hamilton was one of the most original and creative ma...
Read more
|
|
|
dimension
dimension in physics, an expression of the character of a derived quantity in relation to fundamental quantities, without regard for its numerical value. In any system of measurement, such as the metric system, certain quantities are considered fundamental, and all others are considered to be deriv...
Read more
|
