Gianni wrote: > For a hypothetical inhabitant of the Pole (that would have to be extremely > thin and threadlike) it doesn't exist any astronomical phenomenon that can > be used to mark the beginning of the day or the instant from which to start > a whatever system of hours.
There isn't? There is the sun as well as the planet and I think that gives us a reference, if my visualization is correct... The height of the sun varies during the day. Noon is when the sun is highest in the sky. During the polar winter the sun doesn't get above the horizon when it reaches its highest point, but that instant can still define noon. It should be easy to measure the noon direction from the first time we see daylight in the spring of each year - the day the sun sneaks above the horizon for only a very short time. Won't it be the same direction for noon on every other day? Steve -
