# Quick Question: How Did Newton Explain Newton's Rings?

1. Apr 2, 2012

### austinv

Since Newton's rings are clearly a wave phenomenon, and Newton was a strong proponent of the particle theory of light, how did he explain this effect for which he is named?

Thanks!

2. Apr 3, 2012

### Bobbywhy

“Although Opticks was a great success and had won a great number of supporters, the followers of Newtonian optics did not assimilate many of its ideas. The parts that could not be incorporated into Newtonian dynamics, or were too obscure to be easily understood, were ignored or slightly developed. Among them, we can mention the theory of fits of easy transmission and easy reflection, exposed in the Book II of Opticks, and developed to explain the formation of colored rings in thin films, the famous “Newton's rings”. The fits were part of a larger project of Newton. His intention was to develop a unified explanatory model to explain all known optical phenomena, including refraction, reflection and Newton’s rings. For Newton the fits were original properties of light rays, like refrangibility; thus to inquire their origins or causes were not among Opticks purposes (Sabra, 1981). Although the fits of light are a central concept in the Newtonian optics, they were almost ignored or unknown or treated superficially by the 18th century opticians.”

www.ucalgary.ca/ihpst07/proceedings/.../2111%20Silva.pdf [Broken]

Last edited by a moderator: May 5, 2017
3. Apr 3, 2012

### Philip Wood

Newton seemed to think of these 'fits' as some sort of influence which accompanied the particles and determined whether they were reflected or refracted. He did not, I believe, think of them as periodic. Interestingly, Huygens, Newton's contemporary, who championed a wave theory of light, didn't think of his waves as periodic, either. So although Huygens could explain diffraction where λ >> obstacle or slit width, he couldn't explain why the spreading was restricted for smaller λ. If he had been able to do this, he might have converted Newton to a wave theory of light!