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 Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...The Space and Astronomy Agora Re: Radius Of Curvature Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response ToPosted by Rick Crockett on November 8, 2000 17:36:45 UTC

Hi Charles:

Simple principle really, the angle of reflectance (or deflection) is twice the angle of incidence.

If a photon hits a mirror dead on it is reflected directly back. If it hits at any angle, it will be reflected back at an angle of twice that of the incoming photon. Image a mirror and a line sticking straight out from it. If a photon hits the surface at a 15° angle from perpendicular it will be reflected (mirrored) back on the opposite side of perpendicular. This means that there is now 30° between the incoming path and the exit path.

Think of a circle of reflective material. Light from the center hits the side dead on. The center point is the radius of curvature. Now move that light source over 15°. To reflect back to the RoC, the light would have to be deflected 15° but we know that instead it will be 30° and thus crossing a point half way between the surface and the RoC.

Hope this Helps,
-Rick

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