Newton's rings
The phenomenon of Newton's rings is an interference pattern caused by the reflection of light between two surfaces - a spherical surface and an adjacent flat surface. It appears as a series of concentric, alternating light and dark rings centred at the point of contact between the two surfaces. The light rings are caused by constructive interference between the incident and reflected light rays, while the dark rings are caused by destructive interference.
The equation for Newton's rings is as follows:
where
- r is the radius of the dark ring,
- R is the radius of curvature of the lens the light is passing through,
- m is 0,1,2,3... which is dependent upon the number of dark spots,
- λ is the wavelength of the light passing through the glass.
The effect was named after the physicist Isaac Newton, who was the first to analyze it.
External links
- Newton’s Ring from Eric Weisstein's World of Physics
- Carnegie Mellon department of physics, photo images of Newton's rings