MadSci Network: Physics |
I've asked a similar question before which i may not have stated what do i mean in a more appropriate way. Fermat stated that light will take the path which requires the shortest path. So using this we can derive a value of n(refractive index) of a medium. However in the same medium the path with the shortest time is actually the shortest path. So using the same principle, a paraboloidal mirror can be used to reflect light to a focal point. So by using the same principle, one can derive the expression for the curvature of the mirror? (i.e the expression for the parabola) It is stated that by having one general plane which the parallel beams of light passes through at the same time, from the plane to the point on the mirror, it will be reflect in such a way that the light will travel the same distance from the point on the mirror to the focal point. It is stated that using this method, the expression of the curvature can be derived. To be more clear in what i mean, this principle is used to design mirrors which focus light from distant source(light almost become parallel) to a point or this application of the principle can also be seen in making the satellite dish. So i wonder if anyone can provide me with a way to derive the curvature of the mirror. Thanks in advance.
Re: Fermat's principle in optics
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