[time-nuts] Non electrical time-nuttery

[J. Forster]

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..)
>>>>>> _______________________________________________
>>>>>> time-nuts mailing list -- time-nuts at febo.com
>>>>>> To unsubscribe, go to
>>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>>>> and follow the instructions there.
>>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-nuts at febo.com
>>>>> To unsubscribe, go to
>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>>> and follow the instructions there.
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-nuts at febo.com
>>>>> To unsubscribe, go to
>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>>> and follow the instructions there.
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to
>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>>
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>