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B Bent light across the sea

  1. Jun 30, 2018 #1
    I remember reading about how a city could be seen across a sea at certain times. But normally would not be seen because of earth's curvature. At certain times however, it could be seen because of light bending. I can't remember what the cause was though.

    Anyone know about this and what caused it?
  2. jcsd
  3. Jun 30, 2018 #2


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    There is always some refraction due to the atmosphere that causes light to bend in its path and allows you to see a bit beyond the physical horizon. This effect can be increased when there is a temperature gradient in the air, such as when warm air is sitting over a cool body of water. In these cases the distance you can see past the horizon becomes further than it would under normal conditions.
  4. Jun 30, 2018 #3

    Charles Link

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    It might be of interest that the sun is already geometrically set, just about the time when it appears to start to set.
  5. Jul 1, 2018 #4


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