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Q & A: A clock at the Geographic Pole

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Most recent answer: 10/22/2007
Q:
From what I understand the bounderies of all standard time zones intersect at the north and south geographic poles. If you positioned an analog wall clock with the axis of the minute and second hands over this point of intersection, What would be the correct time to set the clock ? Since the clock would be in all time zones at once.
- Larry (age 41)
missouri USA
A:
Hey, fun question!

Actually, time zone boundaries are determined by the vagaries of politics. Some time zones (especially those enclosing little islands in the Pacific) even are not at hour intervals from each other, and have shapes that include just the island. Most of the Earth is divided into time zones that look like the striped surface of a pumpkin, but there are wiggles and detours and all sorts of craziness to some time zone boundaries. But that doesn't address your question, other than to say that time zones are things that we people get to define for our own convenience. Time zones are constructed so that the sun rises in the morning hours and sets in the evening hours, and they give people who travel from faraway places or who communicate with other people in faraway places a convenient way to adjust watches.

Let's consider what happens at the poles. At the pole, the length of one day is one year. The sun stays up all summer, sets in the fall, and rises again the following spring. So there is no need to synchronize a clock with the rising and setting of the sun. The other thing we want is for people who travel to the poles, or who communicate with those at the poles, to know something about the schedules of those who are there (so as not to try to communicate with them when they are sleeping, for insance). Then people should just agree in advance what the time to set the clock to and stick to it.

I'll bet that for international scientific stations, like the one very close to the South Pole in Antactica, "Universal Time" (the time at the observatory in Greenwich, England) is used. At least it's unambiguous. But one could also set one's clock to match that of the science team's collaborators who may come down to visit from time to time or radio in.

Tom

(published on 10/22/2007)

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