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
oscillator.
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.
From solar system to crystal and now atomic, we still dont measure time at
all. It cant be measured, we measure the dynamic behaviour of 'things'
within time, not time itself. To measure you need to take a measure, the
rules of a measurement minimal change to what is being measured. We could
have a billion frequency standards in an area, and apart from increasing the
density of mass in the area, we would not change time. (The assumption is
you dont compress the thunderbolts so dense that you have to use the special
rules of relativity) The concept of time if an oditity, its the same at all
points, but the universe is like measuring jelly with an elastic band! The
universe is expanding at the speed of light, we sit within the ring of this,
we rotate, the solar system does, as do the gallaxies. The concept of any
measure thus becomes problematic, as even the centre of the orginal super
mass, at the start of the big bang, might not be the current assumed center,
this relies on uniform expansion. So is there a reference frame that can be
used, other than two perspectives, or more. Forces come in pairs as well,
frames come in pairs, but time? Unipolar and uniform?
To end this potted note on the pendulum, there is something called pendulum
sympathy. The mass of one pendulum, close to another will mutually effect
each other. The pendulum has had it, regards the recording of time, but it
is fantastic in education to open up pandoras box, what is gravity and what
is energy, we know the latter becomes mass and a force that is left over in
this loop of energy, gravity. Without it nothing would attract, we would
have a universe of uniformity, nothing would join!
It is vital that we preserve the journey, how we attempted to first record
the passing of time, to the synchronisation of society, to the future and
beyond. Nyquist to quote, the highest frequency of the plant, means the
sample time is half this, to be controllable, in a causual system. This is
challenged by predictive control, that if you had a model so good, you could
not tell it from plant, you could vary time and also make time run in
parallel and at different rates. But to run the model twice as fast as
reality, to optimise the clock you would need a clock for the model, oh
another pandoras box, nothing for nothing, something we all want. So does
the clock (sample rate) always have to be twice as fast as what can be
controlled?
I hope that was not too much of the record, and hope you enjoyed the
journey.
We currently need public support for the project, so if you could join the
facebook on www.timemachinefun.com we would all be very grateful.
If any of you want to display to the public your heritage you have saved,
please contact us. Also when you buy industrial heritage, please keep all
the history, what the item was used for, this is living history, it needs to
be captured. I sadly see turret clocks every day out of their context. There
history and duty to us wiped away. A simple post card, that offer a way of
recording tracability, will make you frequency standards preserved with
there history. For this we run www.clocktrust.com and have a historic
frequency standard group, pendulum based, the synchronome. We also run
www.reclaimfun.com, where children take apart mass produced items and do a
treasure trail to find the beating heart, the oscillator.
Very best wishes Paul
Paul Strickland
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