[time-nuts] time-nuts Digest, Vol 70, Issue 31

clock trust contact at clocktrust.com
Thu May 13 08:40:41 UTC 2010

Dear all

A potted history. Before I start a warning I suffer from dyslexia and 
twitter like a buddie, not a god combination. The aim of the effort in 
writting this is to forge a way forward to get young people involved with 
the concept of time and the recording of it. Hence www.timemachinefun.com . 
Also to preserve the industrial heritage. Another sad day, yesturday, an 
important shortts derivate 'frequency standard' went under the hammer. I 
hope the buyer realises what they have brought and need to be done to record 
and preserve this clock/oscillator.

Its quite a while ago that the pendulum was used as an oscillator. In fact 
it was a triple shortts pendulum clock that helped develop quartz 
oscillators, in the bell insititute. They needed a 'rock solid' (gravity) 
reference and at the time the Shortts clock was it.

The pendulum, giving low frequency oscillation, was a mass and a rod. 
Temperature compensation was soon realised and too the affect of humidity 
and air pressure. The other major problem was circular error. So low 
amplitude, in a vacumm! The other compromise, how to keep the pendulum 
going, so it acted like a pure pendulum. It took 300 years of history to 
think outside the box, a free pendulum, first in production the Shortts 
clock, retailed by synchronome.

When the first one was formed it went up the the Royal Astro of the time. He 
first measured the gravity of the earth, over the month the moon, then the 
sun, then the flux due to the wobble of the earth. They knew they had struck 
gold, but it was the end of the pendulum. These elements could be 
compensated for, but not controllable, they needed something to beat, that 
was independent of the solar system and something a bit quicker than parts 
of a second. The rest is history.

If you did compensate for variation of the solar system, you would just peel 
another layer off, you would have to cater for any mass (all mass has 
gravity), even a rain drop or us. We have a Huws model of the shorts clock 
in the TimeMachineFun museum and other technology advances, towards 
synchronisation of society. Just got on display the BBC 1960 crystal 

We take time and frequency synchronisation for granted, without it the whole 
fabric of society would revert back to a much distant time. A time you could 
walk around London, go from church to church, take 30 minutes to do so and 
the time was the same on both dials. From the mechanical age, to electric, 
broadcast, electronic and computer, we have now divided time so precise and 
small, its atomic. Again in the computer age its the division of time that 
holds us back, also making smaller and smaller circuits, running at highwer 
and higher frequencies. Its not steam trains colliding, or data on bus's its 
messing around with groups of particles.

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