Talk:Newton's rings

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[edit] comments

This needs some figures, and connections to other articles on wave optics and thin film interference. It's interesting that one of the external links predicts that the center is dark, while the other one has a photo showing the center being bright! From my own experience, the theory is only a rough description of the reality, and the pattern depends a lot on the angle from which you view it, and on how hard you press the two surfaces together. The page at [1] suggests cleaning: "If the centre fringe is not dark, try polishing the lens and flat with a spectacle cleaning cloth."--Bcrowell 05:56, 8 December 2005 (UTC)

The center really is dark. I saw it myself in a demonstration. The dark point is really really small, inside the big bright first circle. When the instruments used aren't of very good quality, or the photograph taken is of insufficient resolution, I can imagine that you can't see the dark point. Aphexer (talk) 09:50, 22 December 2007 (UTC)

Perhaps worth adding how one uses the phenomenom to make better lenses - as Newton says Newton did. Midgley 02:22, 20 March 2006 (UTC)

[edit] Newton's notion of light

It should be noted that Newton thought that light consists of particles rather than waves. So I'm surprised that its named after Newton (I knew the phenomenon of interference rings but I hadn't heard this name for this special case before I came across this article). 193.154.191.21 01:37, 16 February 2006 (UTC)

What 'Newton thought' was not constant. He tried at one time to make a wave theory work (as in Opticks, Question 13). He even realised that red had a longer wavelength than violet. In the end he gave up the wave theory for the particle theory [2]. --Heron 19:34, 16 February 2006 (UTC)


[edit] Diffraction Pattern

Don;t know if this would be relevant, or ifmy understanding is flawed so thought I should post here first. Am I correct in my understanding that Newton's Rings are a form of a diffraction pattern? Just wondering if anyone else thinks this article might be enhanced by a brief mention of that or a link to the wiki article on diffraction. :) Weenerbunny 17:40, 7 July 2006 (UTC)

[edit] Equation

The equation is off. I will change it ASAP, but I am not very good at the formulas. Here is the link to the page, if anyone else wants to change it, you may. http://www.fas.harvard.edu/~scdiroff/lds/LightOptics/NewtonsRings/NewtonsRings.html It is the second equation, the one for the mth ring. -Hairchrm 20:12, 3 November 2006 (UTC)

[edit] Scanning issues

Newton's rings are a common annoying problem when scanning transparencies. I don't have the time or expertise to explain the solution, but I've seen some scanner operators spread a liquid gel onto a tranny before taping it down to a drum scanner, for example. The other option is to mount a tranny in a special mounting bracket so that the tranny sits in free air instead of next to glass when it's inside a scanner. Dave Laird 06:52, 16 February 2007 (UTC) What is the equation to find the approximate width of the m-th dark fringe? What is the equation to find the approximate width of the m-th bright fringe?

[edit] Interference - diffraction vs reflection

Weenerbunny, Diffraction patterns are formed by interference of light waves scattered by narrow slits or lines, Newton's Rings are formed by interference of light waves reflected from different surfaces. Same effect, but different reasons why waves follows the slightly different path lengths that result in light and dark zones - constructive and destructive interference. Gil johnson 22:18, 29 April 2007 (UTC)