Dear Frank, I request clarification:
Are there limits on the height or length of your wall? I'm thinking of something like Hadrian's Wall, where there is a difference in Local Solar Time between the two ends (but I'd build it longer).
Is the wall straight? In particular, does the whole face have to illuminated at a given instant? The Grianan of Aileach, near by childhood home, is a circular prehistoric hilltop fort with a clear view in all directions. Sunrays can strike it throughout the day, so on the summer solstice it has illumination on some part for around 17 hours (and we could relocate it to the Arctic).
I'm working on it but If I don't use the aforementioned cheats, I've yet to beat Willy's 12 hours (or strictly, if we do not ignore the sun's diameter, the illumination period for 180.5 degrees of travel).
A fun challenge! Steve On 2016-06-14 1:29 AM, Frank King wrote:
Now a simple exercise... What is the maximum amount of time the sun can shine on a vertical wall? You can choose the latitude and you can choose the orientation of the wall and you can choose the solar declination.
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