Circumference and Area: Pi Anyone?GeometryAnatomy of a CircleBasic TermsArcsCircumference and Area: Pi Anyone?TangentsFrom One Theorem Comes Many One of the unusual things about circles is that…
(Encyclopedia) micrometermicrometermīkrŏmˈətər, mīˈkrōmēˌtər [key]. 1 Instrument used for measuring extremely small distances. Typical examples are devices used in astronomical telescopes to measure…
(Encyclopedia) Mitchell, Wesley Clair, 1874–1948, American economist, b. Rushville, Ill. He received his Ph.D. (1899) from the Univ. of Chicago, where he studied under Thorstein Veblen and John Dewey…
(Encyclopedia) Morley, Edward Williams, 1838–1923, American scientist, b. Newark, N.J., grad. Williams College, 1860. From 1869 to 1906 he was professor of chemistry at Western Reserve College (now…
(Encyclopedia) mass-luminosity relation, in astronomy, law stating that the luminosity of a star is proportional to some power of the mass of the star. More massive stars are in general more luminous…
(Encyclopedia) clepsydraclepsydraklĕpˈsĭdrə [key] or water clock, ancient device for measuring time by means of the flow of water from a container. A simple form of clepsydra was an earthenware…
(Encyclopedia) Hertzsprung, EjnarHertzsprung, Ejnarīˈnär hĕrtsˈspr&oomacr;ng [key], 1873–1967, Danish astronomer. Although trained as a chemical engineer, Hertzsprung made his career in astronomy…
(Encyclopedia) Haroche, Serge, 1944–, French physicist, Ph.D. Paris VI Univ., 1971. He was a professor at Pierre and Marie Curie Univ. from 1975 to 2001 and at Paris VI Univ. from 1982 to 2001, when…
(Encyclopedia) Pickering, William Henry, 1858–1938, American astronomer, b. Boston, grad. Massachusetts Institute of Technology (B.S., 1879). He taught at the Massachusetts Institute of Technology (…
