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halo, in meteorology

(Encyclopedia)halo, in meteorology, short-lived circles or arcs, and less commonly spikes and crosses, of colored or whitish light surrounding the moon or sun or in clouds as seen from above. A halo occurs when the...

tropism

(Encyclopedia)tropism trōpˈĭzəm [key], involuntary response of an organism, or part of an organism, involving orientation toward (positive tropism) or away from (negative tropism) one or more external stimuli. ...

aurora borealis

(Encyclopedia)aurora borealis ôstrāˈlĭs [key], luminous display of various forms and colors seen in the night sky. The aurora borealis of the Northern Hemisphere is often called the northern lights, and the aur...

diode

(Encyclopedia)diode dīˈōd [key], two-terminal electronic device that permits current flow predominantly in only one direction. Most diodes are semiconductor devices; diode electron tubes are now used only for a ...

vision

(Encyclopedia)CE5 Optic nerve vision, physiological sense of sight by which the form, color, size, movements, and distance of objects are perceived. Defects of vision include astigmatism, color blindness, far...

Nicol prism

(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...

Akasaki, Isamu

(Encyclopedia)Akasaki, Isamu, 1929–2021, Japanese physicist, b. Chiran, Japan, Kyoto Univ. (BA, 1942), Nagoya Univ. (Ph.D., 1964). Aftger graduating from college, Akasaki worked as an engineer before ...

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...

aureole, in physics

(Encyclopedia)aureole ôrˈēōlˌ [key], in physics, luminous circle seen when the sun or other bright light is observed through a diffuse medium, i.e., smoke, thin cloud, fog, haze, or mist. It sometimes occurs a...

Glauber, Roy Jay

(Encyclopedia)Glauber, Roy Jay, 1925–2018, American physicist, b. New York City, Ph.D. Harvard, 1949. From 1952 he was on the faculty at Harvard, where he became a professor in 1956. Glauber was the co-recipient,...