"Steve Lelievre" <[EMAIL PROTECTED]> wrote: To: <[email protected]> Sent: Saturday, June 21, 2003 2:12 AM Subject: Re: Sundials at Pole
> 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 > - > Steve, You missed Gianni's point, wonderfully expressed, that there is a point at the pole at which the height of the sun does not vary during the day. If the height of the sun varies during the day, you are not at the pole. You might be only a metre away, but that's not close enough. (This assumes that you can measure the sun's altitude very accurately.) So, as Gianni explained, at the very spot that is the north or south pole, noon is meaningless and/or arbitrary. Re-read his posting. To my mind the exquisite humour heightens the vividness of his explanation. Chris Lusby Taylor Newbury 51.4N, 1.3W -
