china has only one time zone, but is the same width as the lower 48. This
causes problems during exams in Urumuchi when the locals there have to get
up in the dark when it is alrteady midmorning in Beijing, so everyone can
sit the exam simultaneously.
With 'solutions' like that, maybe we don't need time zones at all!
India is also wide with only one zone.
So given current political boundaries, probably one answer is the width of
the widest country in which you could have one time zone without distorting
things as much as CXhina or india. Say the width of brazil.
Another way to answer it ias to divide the solar day [of currently 24 hours
duration] into some sensible number. 24 is a nice number, divisible by
2,3,4,6 etc. But perhaps 25 or 20 would be more 'metric'. 100 is too much.
10 too few. 20 would be useful. 10 'hours' of daylight, 10 of night.
I would have thought the 24 hours we have now are Babylonian, long before
Roman. Given we use theuir 360 degrees in a circle, 60 minutes in an hour,
etc.
BW
>From: David Mark <dmark@...>
>Reply-To: BoundaryPoint@yahoogroups.com
>To: BoundaryPoint@yahoogroups.com
>Subject: Re: [BoundaryPoint] Re: Time zone boundaries
>Date: Sat, 12 May 2001 19:49:33 -0400 (EDT)
>
>
>I have asked many academics and received no answer, but this group always
>seems to have answers, so here goes:
>
>if there were no such thing as an hour, what is the optimum or ideal width
>of a time zone?
>
>Time zones are a compromise between a continuously changing standard time
>that is represented by local solar time; and a global standard time with
>everyone setting their clocks to GMT. Before time zones, Philadelphia set
>their clocks 12 minutes different than did New York city. Both of those
>systems have problems.
>
>In the late 19th century, a compromise solution was proposed: time ZONES,
>with a constant standard time within each zone, and a big change at the
>zone boundary. This concentrated all the problems at the boundaries,
>places like White City. If time zones were wider, there would be fewer
>boundaries around the globe, fewer problem places, but within zones
>standard time would get too far from solar time. Narrower zones allow
>closer correspondence between solar and standard time, but more of those
>troublesome time zone boundaries.
>
>We divide the day into 12 hours, and the night likewise into 12 hours,
>because the Romans like the dozen, 12 has so many common factors. And the
>Earth rotates 15 degrees per hour, so that's why the average time zone is
>15 degrees of longitude wide. But what if we had no hour, just 1440
>minutes per day. It would be amazing luck if the idea time zone really if
>60 minutes, or 15 degrees wide. So, a puzzle: Without a unit called an
>hour (= 60 minutes), what would be the ideal width of a time zone?
>
>David
>
>
>
>
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