[time-nuts] Non electrical time-nuttery

Sun Jan 10 02:46:08 UTC 2010

Falling water has been used by the Earl of Meath
to make a sustained pendulum.
It was large and damp and it probably inspired Heath Robinson.
The water fell in a stream that impinged on an angled plate to give a  
force to propel the pendulum.
The stream was then interrupted by a plate on the pendulum rod.
Because the water took a finite time to fall there was a phase shift so
that the returning pendulum missed the water impulse.
The pendulum then drove a count wheel that drove the dial.

Conical pendulums are a good idea except that no-one has found a good  
way to excite them.
They were used on the clock motion of telescopes to track stars for  
time photography,
as you could not afford to have a ticking clock drive.

cheers, Neville Michie

On 10/01/2010, at 1:24 PM, Lux, Jim (337C) wrote:

> Sunlight?  You have a clock driven heliostat generate a fixed beam  
> of light.
> Sure, your sync mechanism only works half the day (half the "clear"  
> days)...
>
> There's a whole literature on regulating light intensity of flames,  
> dating
> back to Faraday, if not earlier.
>
>
> On 1/9/10 6:13 PM, "Bob Camp" <lists at cq.nu> wrote:
>
>> Hi
>>
>> It's probably independent of the light as long as you have a  
>> linear spring. My
>> concern is that you likely do not have a completely linear spring.
>>
>> Since by definition you can't use an electric light, some kind of  
>> gas light
>> would be an option. I suspect that if you regulate pressure you  
>> could keep the
>> light pretty constant.  Dry gas for both the fuel and oxidizer  
>> would take out
>> the humidity issue.
>>
>> Bob
>>
>>
>> On Jan 9, 2010, at 8:39 PM, J. Forster wrote:
>>
>>> No, I don't think so.
>>>
>>> The period of a pendulum is independent of the amplitude of the  
>>> swing to
>>> first order, at least. I think the same applies to a torsional  
>>> pendulum.
>>> Maybe moreso if the fiber is a linear torsional spring.
>>>
>>> -John
>>>
>>> =================
>>>
>>>> Hi
>>>>
>>>> All you would still need is a way to regulate the light intensity.
>>>>
>>>> Bob
>>>>
>>>>
>>>> On Jan 9, 2010, at 7:58 PM, J. Forster wrote:
>>>>
>>>>> Consider this:
>>>>>
>>>>> A torsion pendulum with blackened vanes on the perimeter  
>>>>> suspended from
>>>>> a
>>>>> fiber. Part way up the fiber is an optical shutter and a small  
>>>>> fixed
>>>>> magnet so the shutter is stable in two positions with some  
>>>>> hysteresis.
>>>>> One
>>>>> position lets light fall on the vanes, one does not.
>>>>>
>>>>> This would make an optically pumped pendulum w/ no electronics.
>>>>>
>>>>> -John
>>>>>
>>>>> ==============
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>> Hi
>>>>>>
>>>>>> If you abandoned the non-elecronic side of the requirement,  
>>>>>> you could
>>>>>> hit
>>>>>> it with a pulsed LED and probably get phase data off of a  
>>>>>> couple of
>>>>>> photo
>>>>>> detectors.
>>>>>>
>>>>>> Crazy stuff ...
>>>>>>
>>>>>> Bob
>>>>>>
>>>>>>
>>>>>> On Jan 9, 2010, at 6:21 PM, J. Forster wrote:
>>>>>>
>>>>>>> Maybe you could "pump" the pendulum optically, using a beam  
>>>>>>> of light,
>>>>>>> like
>>>>>>> those glass bulb "radiometers" they sell that spin on a sunny  
>>>>>>> window
>>>>>>> ledge.
>>>>>>>
>>>>>>> -John
>>>>>>>
>>>>>>> =============
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>> Like a magnetically coupled escapement
>>>>>>>> Sent via BlackBerry by AT&T
>>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Bob Camp <lists at cq.nu>
>>>>>>>> Date: Sat, 9 Jan 2010 12:36:11
>>>>>>>> To: Discussion of precise time and frequency
>>>>>>>> measurement<time-nuts at febo.com>
>>>>>>>> Subject: Re: [time-nuts] Non electrical time-nuttery
>>>>>>>>
>>>>>>>> Hi
>>>>>>>>
>>>>>>>> How about a rotary pendulum on a quartz fiber spring with  
>>>>>>>> some kind
>>>>>>>> of
>>>>>>>> trick magnets to drive it  / read it out? Put the pendulum  
>>>>>>>> and spring
>>>>>>>> inside an evacuated glass envelope to get around the vacuum  
>>>>>>>> pump
>>>>>>>> issue.
>>>>>>>> The enclosure could be pretty small.
>>>>>>>>
>>>>>>>> Drive the magnets with a second external clock, and feedback
>>>>>>>> compensate
>>>>>>>> it. Let the external clock do all the readout via a very  
>>>>>>>> normal gear
>>>>>>>> and
>>>>>>>> pointers system. The trick would be getting the feedback  
>>>>>>>> loop to work
>>>>>>>> purely mechanically with enough gain to "unload" the master  
>>>>>>>> pendulum.
>>>>>>>>
>>>>>>>> Bob
>>>>>>>>
>>>>>>>>
>>>>>>>> On Jan 9, 2010, at 2:07 PM, Lux, Jim (337C) wrote:
>>>>>>>>
>>>>>>>>> OK.. So we're moving back in electrical technology....
>>>>>>>>> But what about mechanical?  Could modern technology get a
>>>>>>>>> substantial
>>>>>>>>> (>order of magnitude) improvement over 19th century  
>>>>>>>>> chronometers
>>>>>>>>> (either
>>>>>>>>> pendulum or balance wheel or whatever).  I know there's  
>>>>>>>>> some really
>>>>>>>>> good
>>>>>>>>> quartz fiber torsional spring schemes, but I think they  
>>>>>>>>> still need
>>>>>>>>> electrical means to keep them moving and to read it out.
>>>>>>>>>
>>>>>>>>> So how good can one do with a mechanical, hydraulic, (or  
>>>>>>>>> chemical, I
>>>>>>>>> suppose) system?  Let's assume it has to have a "direct"  
>>>>>>>>> readout
>>>>>>>>> that
>>>>>>>>> is
>>>>>>>>> human readable by a causal bystander.  (this starts to  
>>>>>>>>> sound like
>>>>>>>>> the
>>>>>>>>> 10,000 year clock or whatever it is..)
>>>>>>>>> _______________________________________________
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>>>>>>>>>
>>>>>>>>
>>>>>>>>
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>>>>>>>
>>>>>>>
>>>>>>>
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