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(Encyclopedia)fluoroscope flo͝orˈəskōp [key], instrument consisting of an X-ray machine (see X ray) and a fluorescent screen that may be used by physicians to view the internal organs of the body. During medica...

refraction

(Encyclopedia)refraction, in physics, deflection of a wave on passing obliquely from one transparent medium into a second medium in which its speed is different, as the passage of a light ray from air into glass. O...

Willughby, Francis

(Encyclopedia)Willughby, Francis wĭlˈəbē [key], 1635–72, English naturalist. He is known especially for his early systematic work on birds and fishes, in which he made some of the most important contributions...

devilfish

(Encyclopedia)devilfish, name applied to the manta ray and to an American species of octopus. ...

Roentgen, Wilhelm Conrad

(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...

CAT scan

(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-...

Bragg, Sir William Lawrence

(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...

Hodgkin, Dorothy Mary Crowfoot

(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 (...

reflection

(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...