[Physltest] [Phys-L] Re: Looking for a Mars Clock?

[Karl Trappe <trappe@PHYSICS.UTEXAS.EDU>]

Scott's prank solution actually happened to me as a grad student.  I
was doing heat capacity measurements, turning on a heater for a set
time, then measuring the temperature change.

Unknown to me, the University clocks were set and maintained with a 3
KHz pulse which was superimposed on the line voltage.

I began discovering numerous unknown phase transitions in the sample.
I was elated.  But, I could not get them to reoccur.  At that time,
data was manually transcribed to keypunch cards and the analysis
handled 2 blocks away at the computation center.  Since I was taking
milidegree increments over several degrees, it took quite a while to
figure out that the timer was synchronizing to the intermittent clock
resetting pulses. Of course, my data taking was dependent on sample
cooling via LN2 or LHe, and was not in step with the clocks. Needless
to say, I got rid of that timer...
Thanks for the memories...Karl

> Since you seem to be looking for very cheap (I understand) perhaps you
> can modify a prank we played on a student.
>
> My buddy had a student after for detention. The kid asked if he could
> go and my buddy looked at the clock and said yes. It was later
> discovered that the kid had set the clock forward. This kind of
> challenge cannot be ignored. The detention was rescheduled, but we
> hooked the wall clock up to a lab frequency generator and fiddled until
> the rate was about two to one (parents were informed). The half hour
> detention scheduled was upped to one hour - which actually took two
> hours of clock time.
>
> If you have a freq. generator doing nothing,  you could fake a mars
> clock.
>
>
> Scott
>
>
>
> **********************************
> Scott Goelzer
> Physics Teacher
> Coe-Brown Northwood Academy
> Northwood NH 03261
> 603-942-5531e218
> sgoelzer@coebrownacademy.com
> **********************************
>
> On Jan 13, 2005, at 3:20 PM, Bernard Cleyet wrote:
>
> >  "I am looking for a wall hung Mars clock.  The only one I can find on
> >  the internet is $125 and I can't swing that right now.  Does anyone
> >  know of a source that won't cost quite as much?
> >
> >  Cliff Parker"
> >
> >  If one values their time at say $30/ h as I do, I suspect Brian's $125
> >  is a steal.  A very rough estimate is ~ $30 parts, plus one hour
> >  ordering / driving and purchasing from the local spares store, and a
> >  few hours wiring on a bread board.  The result is not a professional
> >  in appearance (and actually) wall clock.  Of course, if one is
> >  interested in the experience, that's something else.
> >
> >  If there were a demand even 1% of that of earth clocks, Brian could
> >  not compete even if he had to hire a bunch of workers and sold several
> >  a day.  I estimate in such a case he could sell them at ~ < $50, but a
> >  company out shoring to China would sell for, say $25?
> >
> >  bc, very amateur micro-economist.
> >
> >  p.s. I googled mars clock to find the price of Brian's clock (I knew
> >  he'd made one for NASA or an observatory) and assumed that's how Cliff
> >  found it.
> >
> >  p.p.s reminds me of a David Dorfan * statement.  (paraphrase) Rarely
> >  will an analog design work w/o tinkering; usually a digital works
> >  first time.
> >
> >  * Spice expert and teaches analog electronics, inter alia, at UCSC.
> >
> >
> >
> >  Edmiston, Mike wrote:
> >
> > >  By typing "Mars Clock" into Google, I came up with over 600 hits, one
> > >  of
> > >  which has plans for a digital Mars Clock.  Here is the URL
> > >
> > >  http://www.marsbase.net/m/mars-clock.php
> > >
> > >  It's not something anyone can do, but anyone who dabbles with digital
> > >  circuitry could do it.
> > >
> > >
> > >  Michael D. Edmiston, Ph.D.
> > >  Professor of Chemistry and Physics
> > >  Bluffton University
> > >  Bluffton, OH 45817
> > >  (419)-358-3270
> > >  edmiston@bluffton.edu


--
> Dr. Karl I. Trappe, outreach consultant      Home (512) 264-1616
> Research Scientist Associate V,              Desk (512)
> 471-4152/471-1823    Senior Lecturer in Physics
> Physics Department, Mail Stop C-1600
> The University of Texas at Austin
Austin, Texas 78712-1081
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