We discuss mirages formed near a sun-heated wall, and consider the underlying physics. The temperature and refractive index variations in air near the wall are estimated, and a simple approximate picture of ray propagation is presented. Estimates of the thermal decay length and ray curvature are compared with experimental observations.
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Historically, the wall mirage was first studied in 1913 by
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3.
We do not propose that n grows exponentially with distance y, but simply assume that is nearly a constant in the region of interest. The validity of this assumption is examined subsequently.
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© 2000 American Association of Physics Teachers.
2000
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