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Explanation of Newtons Rings

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-486

2025-12-25

688

Explanation of Newton's Rings. When light strikes the lens the refracted ray is partly reflected at A and its phase is changed.¹ Some other refracted ray will be reflected from B without change of phase, and will pass into the air in the same path as the first, CD. If the distance AB is a quarter wave length, the reflected rays are in the same phase and give light; but if it is a half wave length the reflected rays are in opposite phases and there is interference or darkness. As the space between the curved surface of the lens and the plane glass increases gradually, there is a distance that corresponds to a quarter wave length for every color of the spectrum.

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* ¹- A change of phase of half a wave length takes place whenever light is reflected back into a dense medium instead of passing into a rarer one.