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X ray

(Encyclopedia)CE5 Typical X-ray composite spectrum (intensity as a function of frequency) X ray, invisible, highly penetrating electromagnetic radiation of much shorter wavelength (higher frequency) than visibl...

Ray, John

(Encyclopedia)Ray or Wray, John, 1627–1705, English naturalist. He was extremely influential in laying the foundations of systematic biology. With his pupil Francis Willughby, he planned a complete classification...

Ray, Satyajit

(Encyclopedia)Ray, Satyajit sätyäˈjĭt rī, rā [key], 1921–92, Indian film director, b. Calcutta (now Kolkata). His subtle, austere, and delicately lyrical films made him one of the outstanding filmmakers of ...

Roentgen ray

(Encyclopedia)Roentgen ray: see X ray.

Röntgen ray

(Encyclopedia)Röntgen ray: see X ray.

Ray, Man

(Encyclopedia)Ray, Man, 1890–1976, American photographer, painter, and sculptor, b. Philadelphia. Along with Marcel Duchamp, Ray was a founder of the Dada movement in New York and Paris. He is celebrated for his ...

Nagin, Ray

(Encyclopedia)Nagin, Ray (Clarence Ray Nagin, Jr.), 1956–, African-American politician, b. New Orleans. A Louisiana cable-television executive before entering politics, Nagin won the 2002 mayoral election handily...

X-ray crystallography

(Encyclopedia)X-ray crystallography, the study of crystal structures through X-ray diffraction techniques. When an X-ray beam bombards a crystalline lattice in a given orientation, the beam is scattered in a defini...

X-ray astronomy

(Encyclopedia)X-ray astronomy, study of celestial objects by means of the X rays they emit, in the wavelength range from 0.01 to 10 nanometers. X-ray astronomy dates to 1949 with the discovery that the sun emits X ...

gamma-ray astronomy

(Encyclopedia)gamma-ray astronomy, study of astronomical objects by analysis of the most energetic electromagnetic radiation they emit. Gamma rays are shorter in wavelength and hence more energetic than X rays (see...