Columbia Encyclopedia

(Encyclopedia) Roentgen or Röntgen, Wilhelm Conrad both: rĕntˈgĭn, rŭntˈ–, Ger. vĭlˈhĕlm kônˈrät röntˈgən [key], 1845–1923, German physicist. His notable research in many fields of physics, especi...

(Encyclopedia) CAT scan kăt [key] [computerized axial tomography], X-ray technique that allows relatively safe, painless, and rapid diagnosis in previously inaccessible areas of the body; also called CT scan. An X-...

(Encyclopedia) Delany, Samuel R. (Samuel Ray Delany, Jr.), 1942–, African-American wrtier, b. Harlem, New York City. Delany uses science fiction, fantasy, and memoir to explore sexual identity, race, language, and...

(Encyclopedia) Old Man of the Mountain, in Islamic history: see Assassin. ...

(Encyclopedia) Bragg, Sir William Lawrence, 1890–1971, English physicist, b. Adelaide, Australia, educated in Australia and at Trinity College, Cambridge; son of W. H. Bragg. He was professor of physics at Victori...

(Encyclopedia) Dada däˈdäĭzəm [key], international nihilistic movement among European artists and writers that lasted from 1916 to 1922. Born of the widespread disillusionment engendered by World War I, it orig...

(Encyclopedia) Hodgkin, Dorothy Mary Crowfoot, 1910–94, English chemist and X-ray crystallographer, b. Egypt. She received the 1964 Nobel Prize in chemistry for determining the structure of biochemical compounds (...

(Encyclopedia) Old Man of the Mountain, N.H.: see Franconia Mountains. ...

(Encyclopedia)  CE5 Image formation by curved mirrors and lenses reflection, return of a wave from a surface that it strikes into the medium through which it has traveled. The general principles governing the ref...

(Encyclopedia) Nicol prism nĭkˈəl [key], optical device invented (1828) by William Nicol of Edinburgh. It consists essentially of a crystal of calcite, or Iceland spar, that is cut at an angle into two equal piec...