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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: NG's "Midnight Fun"
From: UNK
Date: 2010 Jun 11, 13:43 +0000
From: UNK
Date: 2010 Jun 11, 13:43 +0000
George Huxtable wrote: > It's > clear that the gaps between the Sun images, nominally 5 degrees, are > increasing as they depart from the centre region > It did not notice this before. These gaps increase roughly in proportion to the height of the sun over the horizon. > Even after all this, the enhancement of the dimensions of the outer Suns on > that picture seems even greater than the simple pinhole model would > predict. Exactly. This was the point of my comment to Peter. If we measured the height of the sun in multiples of its apparent diameter at each moment, the actual sun would be lower towards the edges than in the middle. So, if I understand correctly what George is saying, it's a combination of effects and the horizontal spacing of the sun images gives us a measure of how much is due to distortion. Herbert Prinz