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 <[email protected]> >>>>> Date: Sat, 9 Jan 2010 12:36:11 >>>>> To: Discussion of precise time and frequency >>>>> measurement<[email protected]> >>>>> 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 -- [email protected] >>>>>> To unsubscribe, go to >>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>> and follow the instructions there. >>>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> >> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
