On Mon, 23 Jan 2006, John Cowan wrote: > Rob Seaman scripsit: > > that it can be reliably recovered from observations whenever and > > wherever needed (once you are located with respect to a meridian, of > > course). > > I don't understand this. You can't shoot the mean sun with a sextant, > only the friendly ("apparent", whatever) sun. So at the very least > you need an analemma.
I don't think Rob meant the above to be a complete course on navigation! > > In any case, the majority of the world has managed to live with the fact > that the day-of-month can no longer be recovered by examining the moon, > although if we were still hunter-gatherers a purely lunar calendar would > make a lot of sense. Good example of a timekeeping decision made by a (very tiny) minority over the majority. How nice indeed, it would be, if the months were fixed to match lunations. February could be a leap-month which changes length when necessary to keep the synchronization... Pete.