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A blur can be seen when fingers almost touch

I can see this with my bare eyes enter image description here

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You are essentially observing an interference effect. This is equivalent to what you would see in a single slit experiment.

The fringes are caused as the light rays that passes between your fingers are travelling slightly different distance to reach you eye. This causes their phases to be somewhat different. As a result the light rays partially cancel, causing the blur.

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  • $\begingroup$ Isn't it diffraction? $\endgroup$ – Courage Nov 26 '15 at 10:36
  • $\begingroup$ It would be interesting to see why we only see a diffraction minimum and no maxima. Maybe it's because the source is incoherent. $\endgroup$ – jinawee Nov 26 '15 at 11:06
  • $\begingroup$ You can see The minimums and maximums. This picture is not clear but if you look real close in your own fingers you will see stripes of dark lines. The dark stripes or minimums and in between our maximum. $\endgroup$ – Bill Alsept Nov 27 '15 at 9:26

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