Eric - I like your creative suggestions for displays. Regarding the pendulum - you could add: observing how the period changes with amplitude. A notable portion of technical people think that the period of a pendulum is independent of the amplitude of its swing. Of course, anyone in this field knows it is only approximately true for arbitrarily small-amplitude swings, the general case being given by Jacobi's elliptic function rather than a harmonic solution. Skip Newhall JPL (Retired) ----------------- Skip Newhall ------------------ Valencia, CA E-mail: [email protected] Phone: 1-661-259-9999 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Eric Fort Sent: Tuesday, April 03, 2012 1:40 PM To: Leap Second Discussion List Subject: Re: [LEAPSECS] props for talks? Somewhat depends upon the intended audience but the following items come to mind and I'll finish with 2 references from which to pick more. The props chosen might also depend somewhat at to what "the presented philosophy of what time is" is. Here's a few things that come to mind: Various calendars (Mayan, Hebrew, Julian, Gregorian, etc. illustrating their significance <and making a joke or 2 about the "end of time" according to the Mayan long count coming soon) . Telescope/transit/sextant - translate where you are to when it is. Rubidium Oscillator (a cesium beam is probably a bit big to take along but a modern rubidium easily fits in a suitcase) WWV/WWVH audio receivers WWVB and GPS receivers with display (time/frequency transfer methods & radio controlled clocks) finished and unfinished quartz crystals. marine chronometer pendulum (could be as simple as a mass on a string, variable length being nice as one can observe how the period changes with length <and with variation in g should you be able to arrange such ;) > ) heliometer pocket watch clepsydra (aka water clock) candles Hourglass sundial tally stick (used for the counting of days) Eric On Tue, Apr 3, 2012 at 10:59 AM, Rob Seaman < <mailto:[email protected]> [email protected]> wrote: > > I'm giving a colloquium in a couple of weeks and would welcome suggestions > for neat timekeeping gizmos (borrowed or bought) to spark interest. > > Rob > > _______________________________________________ > LEAPSECS mailing list > <mailto:[email protected]> [email protected] > <http://six.pairlist.net/mailman/listinfo/leapsecs> > http://six.pairlist.net/mailman/listinfo/leapsecs _______________________________________________ LEAPSECS mailing list <mailto:[email protected]> [email protected] <http://six.pairlist.net/mailman/listinfo/leapsecs> http://six.pairlist.net/mailman/listinfo/leapsecs
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