Re: [LEAPSECS] UTC is doomed

From: Steve Allen <>
Date: Mon, 28 Apr 2003 01:26:02 -0700

On Thu 2003-04-24T13:20:03 -0700, Brian Garrett hath writ:
> By the time the size of DUT1 reaches hit-the-fan levels, I suspect the
> current political squabbles will have gone away and we'll have found a new
> set of squabbles to occupy ourselves with that (one presumes) will not
> directly involve the country in which BIPM is located. I can't imagine how
> any time scale linked with TAI could possibly be associated in the mind of
> any government with a particular nation, hostile or otherwise.

My wife reminds me that although the SI kilogram and meter have been
_a_ legal system of weights and measures in the US since 1866, they
are not _the_ legal system of weights and measures. Most commerce
still uses the "customary" or "common" measures whose origins predate
the constitution. I do not know the history of efforts to make SI
_the_ legal system for the US, but clearly they have not succeeded.
In the mean time, the officially legal system is not widely used, and
the widely used system is not officially legal.

At least part of the reason for lack of congressional action to
require use of SI must be that there is no need for action. In 1893
the kilogram and meter became the "fundamental" standards for the US.
Since then the common/customary units have simply been defined in
terms of the SI units. In 1983 the SI meter became defined in terms
of the SI second, so the SI second is now (albeit indirectly) the
legal basis for length, area, and volume, but not time, in the US.

It makes no difference to commerce and daily life that the US survey
inch is 1/39.37 m and the international inch is 0.0254 m, for those
values remain constant and almost nobody has to think about that now
or ever. One of the only things that would be accomplished if
congress acted to require the use of SI units would be the alienation
of all commerce that currently uses common/customary units.

I am not convinced that there is an easy way to predict the reaction
of the US Congress to a sudden need to redefine legal time. Would
they really adopt a change that leaves an open question about what to
do in 600 years when they know that the status quo is good for about
1700 years? How would that be motivated?

It seems safer to engage in a major effort of education to make it
clear that what humanity has always thought of as time is really just
a stochastically increasing angle, and that measurement of what we
understand to be actual time requires a separate mechanism.

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 Mon Apr 28 2003 - 01:26:14 PDT

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