Re: [LEAPSECS] the tail wags the dog

From: Steve Allen <sla_at_UCOLICK.ORG>
Date: Mon, 23 Jan 2006 10:12:55 -0800

On Mon 2006-01-23T09:33:10 -0700, M. Warner Losh hath writ:
> (the term mean
> solar time isn't legally defined, but does have an accepted scientific
> meaning).

Would that it were so, but I don't believe it because I've read the
proceedings of the IAU general assemblies and related papers. I've
seen the arguments which arose when it became clear that Newcomb's
constant of aberration was distinctly wrong, and about the Fictitious
Mean Sun and whether that concept needed to be revised to distinguish
it from the Fictitious Mean Apparent Sun.

The concept of using a single expression for calulation of mean solar
time worldwide was meant to solve the telecommunications problem of
scheduling telegraphic communications across the trans-oceanic cables
which were first laid in the 1860s and 1870s. To that end, one second
was plenty good. It was still plenty good in the manually-keyed radio
age of 1918 when the US Calder act originally specified "mean
astronomical time" as the legal time.

Science is a process, as are technology and law.
The processes are not perfect; they do not have good foresight.
The accumulated "oh wow, look at that", "how about this?",
"let's just do that" has resulted in the kludge on a hack set of
time distribution schemes upon which we ruminate.

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 Jan 23 2006 - 10:13:12 PST

This archive was generated by hypermail 2.3.0 : Sat Sep 04 2010 - 09:44:55 PDT