[LEAPSECS] ISO TC 37

[Tom Van Baak]

> Well I've always interpretted it as a "co-ordinated form of UT". Steve Allens next email implies others viewed it that way as well.


Stephen,

My reading of the original documents in the 60's is that the
"co-ordinate" was both astronomical-atomic and atomic-atomic.

I don't know how old you are, but recall that in those years it
was a massive effort to synchronize the atomic clocks of each
national timing laboratory. Everyone completely takes it for
granted these (post-GPS) days that all labs agree on the SI
second or agree what time it is to the nanosecond.

But this was not at all the case in the 60's where countries or
labs would vary by tens or hundreds of microseconds or even
many milliseconds.

See: http://www.leapsecond.com/hpj/v17n12/v17n12p16.jpg
And: http://www.leapsecond.com/hpj/v19n4/v19n4p18.jpg

A huge part of UTC was the formation of the paper clock where
all national labs contributed to the ensemble. This has little or
nothing to do with the earth or stars. No one back then doubted
that a competent astronomer or navigator knew how to apply a
simple DUT1 correction to UTC before they pointed a telescope
or steered a ship.

It won't bother me one way or another what ITU decides or
how UTC evolves over time, but I sure hope that astronomers
wake up, stop complaining, and use UT1 and DUT1 for what
they were designed for.

/tvb
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