This list - together with all the additions - is great ! But, it would be nice to see which of the many items can be done well by a sundial and how many items would be a 'stretch'. To find the moment of equinox - for example - is theoretically possible - but in actuality is not realistic since the Sun's declination is changing so slowly at those times: (a problem the astronomers of antiquity struggled with). Equally, I think one would be hard pressed to find aphelion & perihelion from a dial - except in a very indirect fashion.
But let's get the list complete ! Best regards Kevin Karney On 16 Nov 2010, at 21:38, Jos Kint wrote: > Dear sun dialists, > > What can be calculated with a good sun dial? Here is a list of 19 topics. Can > you add some more items? > 1. The hour of the day > 2. The day of the year. > 3. The solar altitude. > 4. The solar azimuth. > 5. The longitude of the sun dial. > 6. The latitude of the sun dial. > 7. The moment of the equinoxes > 8. The moment of the solstices. > 9. The length of the tropical year > 10. The equation of time > 11. The excentricity of the earth orbital around the sun. > 12. The obliquity of the eclips > 13. A compass function > 14. The declination of the sun. > 15. The moment of the perihelion > 16. The moment of the aphelion > 17. The moment of the next sun set > 18. The Babylonic time > 19. The Italian time > > > Jos Kint > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial >
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