[time-nuts] Pendulums & Atomic Clocks & Gravity

[John Ackermann N8UR]

Tom Van Baak said the following on 05/26/2007 10:51 PM:

> I don't know how many time nuts are interested in this but
> you need to realize that the first hint that the Earth itself was
> an unstable timekeeper came, not from quartz or atomic
> oscillators, but from these astronomical pendulum clocks.

This is another chance to plug one of my favorite books, Tuxedo Park by
Jennet Conant (ISBN 978-0684872889).

It's the story of Alfred Loomis, an amateur physicist of extreme talent,
who was also a Wall Street operator on the highest levels.  He made
himself a large fortune in the 20s, and was clever enough to sell out
just before the great crash.  He was one of the initial forces behind US
scientific mobilization before WW2, and some of the original radar
research was done at his mansion/laboratory in Tuxedo Park, NY.

The time-nuts link is that he was interested in precise timekeeping.  On
a trip to London, he stopped in to Shortt's shop and ordered three of
his clocks, paying up-front for them.  This was at a time when Shortt
had sold maybe half a dozen!

He put the three clocks on separate pedestals solidly connected to the
bedrock below his home.  They were accurate enough that he was able to
observe their gravitational interaction -- he had to arrange them so the
pendulums swung at 120 degree angles to each other in order to avoid
what we would call injection locking!

He used the clocks to measure earth's rotation among other experiments.
 He also had early quartz oscillators and had a dedicated phone line to
Bell Labs where they sent him a 1kHz tone generated from their quartz
standard for intercomparison.

One of the anecdotes in the book is that Loomis would send QSL cards to
the various national time/frequency broadcasters, carefully noting how
much they were in error!

John