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I forgot to bring the second possibility. To define the concept of mean time, consider two fictitious mobiles (suns): 1. The ecliptic mean sun or the mean position of the sun. It is the same mean sun as the one from the Almagest, Al-Battani, and Maimonides. Today, it is called the fictitious sun. It moves on the ecliptic at the mean solar velocity of 360° per tropical year, and it coincides with the true sun at the perigee (currently January 3) and at the apogee (currently July 4). 2. The equatorial mean sun (also called the mean sun today), which moves uniformly on the equator at the same mean angular velocity as the ecliptic mean sun. source: http://www.ajdler.com/jjajdler/EoT.pdf My request is can anyone comment, if number one is true concerning at least part of the Ptolemaic Tables and how does this work out with ancient sundials that are showing equinoctial hours. As well can anyone tell me how one would calculate these mean ecliptic hours from our mean equatorial hours? Thanks, Noam Kaplan 31.651756 N 35.126424 E |
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