Re: [LEAPSECS] Wall Street Journal Article

From: Steve Allen <sla_at_UCOLICK.ORG>
Date: Mon, 1 Aug 2005 13:14:42 -0700

On Mon 2005-08-01T15:40:58 -0400, John.Cowan hath writ:
> As should be eminently clear by now, I absolutely oppose leaps of any kind,
> whether seconds or hours, in universal time (lower case generic term).
> Hours are certainly worse than seconds in this respect.

Sic semper faciebamus.

Since the inception of clocks and the use of sexagesimal format
for communicating time of day -- we've always done it this way.
The whole point of the 24:60:60 notation is to match up with the day.
In order to do that all civil time scales have always had leaps or
seconds of non-uniform length or both.
Dynamical time and atomic time have no such concept and should always
have been communicated as a decimal count of elapsed seconds.

Confusing the one entity with the other in the original definition of
Ephemeris Time was perhaps the biggest timekeeping mistake ever made
by astronomers.

Not following the suggestion to define the cesium-based,
Ephemeris-Time-inspired unit of duration as a new unit called the
Essen was perhaps the biggest timekeeping mistake ever made by physicists.

Allowing civilian entities to believe that the broadcast time signals
originally intended for navigation could also be used for setting
civil time was perhaps the biggest timekeeping mistake ever made by
the CCIR (now ITU-R) and all the national time services.

But the cascade of all of these historical booboos has created a set
of sociological, technological and legal easements which cannot easily
be abolished. In legal dealings with land use one cannot abolish such
right-of-ways without unanimous agreement or a public court process.

> Eventually that will become impossible. When solar days are 48 (current)
> hours long, we will just have to get used to the idea that every other
> waking period is in darkness.

Duncan Steel made the point very well in his book on calendars: there
is no point in trying to create a scheme which is expected to be valid
for more than 1000 years.

Nobody is worried about 40000 years hence when the analemma of mean
solar time has tilted back and forth twice and a leap second is
needed every day, but the new GPS interface control documents specify
a new counter of leap seconds which will serve for 30000 years.

The issue is whether to replace an existing system that matches the
practice of all history but will fail in about 1200 years with a new
system that violates the practice of all of history and will fail in
about 600 years. There should be no rush to do this without
considering all alternatives and coming to a broad consensus.

Steve Allen                 <>                   WGS-84 (GPS)
UCO/Lick Observatory        Natural Sciences II, Room 165       Lat  +36.99858
University of California    Voice: +1 831 459 3046              Lng -122.06014
Santa Cruz, CA 95064        Hgt +250 m
Received on Mon Aug 01 2005 - 13:14:58 PDT

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