[LEAPSECS] presentations from AAS Future of Time sessions

[Steve Allen]

On Sat 2014-01-11T21:43:02 -0800, Brooks Harris hath writ:

> Any help getting to the bottom of this appreciated.


It's history, and it's confused.  Measurement techniques were crude
and people were not cognizant that there was more than one thing being
measured.  Measurement techniques are vastly improved and some people
understand better, but even the best current knowledge cannot
unconfuse the folks in the past or be sure how to interpret their
understanding using a modern vocabulary and reference frame.

NASA technical report number 70 by Hans D.  Preuss of the Department
of Geodetic Science at Ohio State University "The Determination and
Distribution of Precise Time" is relevant to read to see how badly
confused the situation was in the 1960s
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670028967_1967028967.pdf

NIST has many of the old NBS publications scanned and online at their
website, and many of the announcements of rationales and dates when
decisions were made to change the radio broadcasts are scattered among
those.  Their publication with most dense collection of such facts is
NBS Monograph 140 which can be found at
http://digicoll.manoa.hawaii.edu/techreports/PDF/NBS140.pdf

But nobody is going to reset their clocks based on a new understanding
of when an epoch was nor what kinds of seconds were being counted.
Tabulating historic differences between the values of various time
scales is of little relevance to the decision before the ITU-R.
How they handle the leap second issue will assert whether humanity has
any intent of keeping the meaning of the word "day" to be based on the
rotation of the earth.

--
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