Einstein Rings vs. Newton Rings

Newton Rings are an interference phenomenon that occur when a curved lens and a flat lens are placed on one another. The equation governing this phenomenon follows:






where r_N is the radius of Nth Newton's bright ring, N is the bright ring number, R is the radius of curvature of the lens the light is passing through, and lambda is the wavelength of the light passing through the glass.

An Einstein ring is a sort of gravitational lensing that occurs around stars. It is governed by the following equation:













For a long time, I was entertaining the thought that these two phenomena were somehow linked. The physical mechanisms that cause each are very different, but both include some sort of lenses or lensing (Newton's rings require curved and flat glass lenses, Einstein's rings require gravitational lensing). However, the equations seem very different; the Newton's ring equation depends on lambda (the wavelength of the light), while the Einstein's ring equation doesn't. Also, Newton's rings refers to a set of concentric rings produced by one lens set, while Einstein's rings refer to a single ring or fragments of a ring around one light-emitting body in space.

So, the word for now is that Einstein's and Newton's rings are not linked... but we shall see -- more research is to come.