|MadSci Network: Physics|
Many times these interference properties are investigated through the use of diffraction gratings. A grating is a huge collection of tightly spaced slits - usually upwards of 5 x 105 slits per meter. The distance between the slits in a grating is calculated as the reciprocal of its grating spacing. That is d = 1/[number of slits/meter] http://dev.physicslab.org/Document.aspx? Brian D. Prater
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