refraction

• POS: Noun
• HYPHEN: re=frac=tion

CIDE DICTIONARY

refraction, n. [F. réfraction.].

•  The act of refracting, or the state of being refracted.  [1913 Webster]
•  The change in the direction of ray of light, heat, or the like, when it enters obliquely a medium of a different density from that through which it has previously moved.  [1913 Webster]

  "Refraction out of the rarer medium into the denser, is made towards the perpendicular."  [1913 Webster]
•  The change in the direction of a ray of light, and, consequently, in the apparent position of a heavenly body from which it emanates, arising from its passage through the earth's atmosphere; -- hence distinguished as atmospheric refraction, or astronomical refraction.  [1913 Webster]

Angle of refraction (Opt.), the angle which a refracted ray makes with the perpendicular to the surface separating the two media traversed by the ray. -- Conical refraction (Opt.), the refraction of a ray of light into an infinite number of rays, forming a hollow cone. This occurs when a ray of light is passed through crystals of some substances, under certain circumstances. Conical refraction is of two kinds; external conical refraction, in which the ray issues from the crystal in the form of a cone, the vertex of which is at the point of emergence; and internal conical refraction, in which the ray is changed into the form of a cone on entering the crystal, from which it issues in the form of a hollow cylinder. This singular phenomenon was first discovered by Sir W. R. Hamilton by mathematical reasoning alone, unaided by experiment. -- Differential refraction (Astron.), the change of the apparent place of one object relative to a second object near it, due to refraction; also, the correction required to be made to the observed relative places of the two bodies. -- Double refraction (Opt.), the refraction of light in two directions, which produces two distinct images. The power of double refraction is possessed by all crystals except those of the isometric system. A uniaxial crystal is said to be optically positive (like quartz), or optically negative (like calcite), or to have positive, or negative, double refraction, according as the optic axis is the axis of least or greatest elasticity for light; a biaxial crystal is similarly designated when the same relation holds for the acute bisectrix. -- Index of refraction. See under Index. -- Refraction circle (Opt.), an instrument provided with a graduated circle for the measurement of refraction. -- Refraction of latitude, longitude, declination, right ascension, etc., the change in the apparent latitude, longitude, etc., of a heavenly body, due to the effect of atmospheric refraction. -- Terrestrial refraction, the change in the apparent altitude of a distant point on or near the earth's surface, as the top of a mountain, arising from the passage of light from it to the eye through atmospheric strata of varying density.

OXFORD DICTIONARY

refraction, n. the process by which or the extent to which light is refracted.

Idiom

angle of refraction the angle made by a refracted ray with the perpendicular to the refracting surface.

Etymology

F r{eacute}fraction or LL refractio (as REFRACT)

THESAURUS

refraction

atmospheric attenuation, blind spots, clutter, deflection, deflexure, diffraction, diffusion, dispersion, distortion, false echoes, flection, flexure, ground clutter, scatter, sea clutter, skewness, superrefraction, torsion

ROGET THESAURUS

refraction

Deviation

N deviation, swerving, obliquation, warp, refraction, flection, flexion, sweep, deflection, deflexure, declination, diversion, digression, depart from, aberration, divergence, zigzag, detour, divagation, wandering, vagrancy, evagation, bypaths and crooked ways, byroad, sidling, knight's move at chess, deviating, aberrant, errant, excursive, discursive, devious, desultory, loose, rambling, stray, erratic, vagrant, undirected, circuitous, indirect, zigzag, crab-like, astray from, round about, wide of the mark, to the right about, all manner of ways, circuitously, obliquely, sideling, like the move of the knight on a chessboard.

Light

N light, ray, beam, stream, gleam, streak, pencil, sunbeam, moonbeam, aurora, day, sunshine, light of day, light of heaven, moonlight, starlight, sunlight, daylight, broad daylight, noontide light, noontide, noonday, noonday sun, glow, glimmering, glint, play of light, flood of light, phosphorescence, lambent flame, flush, halo, glory, nimbus, aureola, spark, scintilla, facula, sparkling, emication, scintillation, flash, blaze, coruscation, fulguration, flame, lightning, levin, ignis fatuus, luster, sheen, shimmer, reflexion, reflection, gloss, tinsel, spangle, brightness, brilliancy, splendor, effulgence, refulgence, fulgor, fulgidity, dazzlement, resplendence, transplendency, luminousness, luminosity, lucidity, renitency, nitency, radiance, radiation, irradiation, illumination, actinic rays, actinism, Roentgen-ray, Xray, photography, heliography, photometer, optics, photology, photometry, dioptrics, catoptrics, chiaroscuro, clairobscur, clear obscure, breadth, light and shade, black and white, tonality, reflection, refraction, dispersion, refractivity, shining, luminous, luminiferous, lucid, lucent, luculent, lucific, luciferous, light, lightsome, bright, vivid, splendent, nitid, lustrous, shiny, beamy, scintillant, radiant, lambent, sheen, sheeny, glossy, burnished, glassy, sunny, orient, meridian, noonday, tide, cloudless, clear, unclouded, unobscured, gairish, garish, resplendent, transplendent, refulgent, effulgent, fulgid, fulgent, relucent, splendid, blazing, in a blaze, ablaze, rutilant, meteoric, phosphorescent, aglow, bright as silver, light as day, bright as day, light as noonday, bright as noonday, bright as the sun at noonday, actinic, photogenic, graphic, heliographic, heliophagous, a day for gods to stoop and men to soar, dark with excessive bright.

Dimsightedness

N dimsightedness, dim sight, dull sight half sight, short sight, near sight, long sight, double sight, astigmatic sight, failing sight, dimsightedness, purblindness, lippitude, myopia, presbyopia, confusion of vision, astigmatism, color blindness, chromato pseudo blepsis, Daltonism, nyctalopia, strabismus, strabism, squint, blearedness, day blindness, hemeralopia, nystagmus, xanthocyanopia, xanthopsia, cast in the eye, swivel eye, goggle-eyes, obliquity of vision, winking, nictitation, blinkard, albino, dizziness, swimming, scotomy, cataract, ophthalmia, blinker, screen, deceptio visus, refraction, distortion, illusion, false light, anamorphosis, virtual image, spectrum, mirage, looming, phasma, phantasm, phantasma, phantom, vision, specter, apparition, ghost, ignis fatuus, specter of the Brocken, magic mirror, magic lantern, mirror lens, dim-sighted, myopic, presbyopic, astigmatic, moon-eyed, mope-eyed, blear-eyed, goggle-eyed, gooseberry-eyed, one-eyed, blind of one eye, monoculous, half-blind, purblind, cock-eyed, dim-eyed, mole- eyed, dichroic, blind as a bat, winking.