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Re: shortest twilight problem...
From: Marcel Tschudin
Date: 2010 Jun 29, 18:48 +0300
From: Marcel Tschudin
Date: 2010 Jun 29, 18:48 +0300
The day of shortest twilight actually does depend on latitude. The attached graph shows the durations at the equator. The conditions are the same as for the graph at 41 deg latitude. At the spring equinox the minimum for the morning twilight is on 20 MAR 2010 and for the evening twilight on 18 or 19 MAR 2010 (same duration in seconds). At the autumn equinox the minimum of the morning twilight is between 21 and 24 SEP 2010 (same duration in seconds) and the evening twilight between 20 and 23 SEP 2010 (same duration in seconds). I guess the challenge must have been to calculate how this depend on the geometrical parameters. Marcel
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