Newton's rings

Newton's rings
the pattern of light interference produced by the contact of the convex surface of a lens with a plane glass plate, appearing as a series of concentric, alternately bright and dark rings, which are colored if the light source is white.
[1825-35; after I. NEWTON, who discovered them]

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▪ optics
      in optics, a series of concentric light- and dark-coloured bands observed between two pieces of glass when one is convex and rests on its convex side on another piece having a flat surface. Thus, a layer of air exists between them. The phenomenon is caused by the interference (interference fringe) of light waves; i.e., the superimposing of trains of waves so that when their crests coincide, the light brightens; but when trough and crest meet, the light is destroyed. Light waves reflected from both top and bottom surfaces of the air film between the two pieces of glass interfere. The rings are named after the English 17th-century physicist Sir Isaac Newton, who first investigated them quantitatively.

 The principle is often used in testing the uniformity of a polished surface by studying the interference pattern the surface makes when placed in contact with a perfectly flat glass surface. The figure—> shows contour patterns formed by various surfaces under test. In the figure, A is produced by a flat surface with point of contact at X. In B and C the test surface is slightly convex, the points of contact indicated by X in each case. An irregular surface may give an interference pattern shown in D, with two points of contact X1 and X2.
 

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Universalium. 2010.

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Look at other dictionaries:

  • Newton's rings — observed through a microscope. The smallest increments on the superimposed scale are 100μm …   Wikipedia

  • Newton's rings — n pl colored rings due to light interference that are seen about the contact of a convex lens with a plane surface or of two lenses differing in curvature …   Medical dictionary

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  • Newton's rings — /ˈnjutnz rɪŋz/ (say nyoohtnz ringz) plural noun coloured concentric rings which are produced by interference of light round the point of contact of a convex lens and a plane reflecting surface. {named after Sir Isaac Newton} …  

  • newton's rings — noun plural Usage: usually capitalized N : colored rings due to light interference that are seen about the contact of a convex lens with a plane surface or of two lenses differing in curvature …   Useful english dictionary

  • Newton's rings — plural noun Optics circular interference fringes seen around the point of contact of a convex lens and a plane surface …   English new terms dictionary

  • Newton, Sir Isaac — born Jan. 4, 1643, Woolsthorpe, Lincolnshire, Eng. died March 31, 1727, London English physicist and mathematician. The son of a yeoman, he was raised by his grandmother. He was educated at Cambridge University (1661–65), where he discovered the… …   Universalium

  • Newton , Sir Isaac — (1642–1727) English physicist and mathematician Newton s father, the owner of the manor of Woolsthorpe in Lincolnshire, died three months before Newton was born. The family had land but were neither wealthy nor gentry. Left by his mother in the… …   Scientists

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