the analemma

From: Steve Allen <>
Date: Sat, 23 Aug 2003 02:49:42 -0700

On Sat 2003-08-23T01:55:17 -0700, Steve Allen hath quoted:
> the serious dissensions between those concerned with standard
> frequencies and those who request a time system connected with the
> Earth's rotation (astronomers, geodesists, navigators etc.) and

I also find it a bit curious to see that many of the current articles
about leap seconds take statements like this to be complete.

When leap seconds were instituted into UTC it did not serve only the
astronomers, geodesists, and navigators. As the IAU noted in 1973, it
also served to keep radio time broadcasts providing what radio time
broadcasts had always provided -- mean solar time as specified in the
legal systems of most countries. It means that people could continue
to set their watches to the statutory time just by listening to a
short wave radio. If radio broadcasts switch from UT to atomic time
without concomitant change in legislation, then it is hard to imagine
how people will be able to know to "listen for the tone then wait N
seconds before setting your watch". Of course we should just
postulate that watches of the future will do that sort of thing for
us, and that their user interface will even permit choice of timezone.
And then owners of grandfather(ed) clocks will just set them by
referring to their self-aware wristwatches.

Alternatively, if legislation does follow the new form of ITU-R TF.460
and assert that legal time is atomic time then the analemma breaks.
In pictorial terms, all of the following become smeared out from year
to year

and all of these works of art fail to tell time anymore

The general public will generally believe that it is any time that
they are told to believe, but everyone would comprehend these.

Steve Allen          UCO/Lick Observatory       Santa Cruz, CA 95064      Voice: +1 831 459 3046
PGP: 1024/E46978C5   F6 78 D1 10 62 94 8F 2E    49 89 0E FE 26 B4 14 93
Received on Sat Aug 23 2003 - 02:49:51 PDT

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