[time-nuts] gravity controlled pendulumn clock?
Tom Van Baak
tvb at LeapSecond.com
Mon Dec 12 06:33:47 EST 2011
Jim Lux writes:
> intriguing. From your parenthetical remark, I'm assuming you move the
> whole assembly up and down to adjust the speed?
> I was thinking about a huge mass that moves around?
Got one already -- it's called the moon!
> let's see.. period is proportional to sqrt(1/g)
> g is proportional to 1/r^2, so period is proportional to r.
> Earth is roughly 7000 km radius, so moving it 1 meter higher or lower
> changes the period by 1part in 7million... interesting.
Yes, cool isn't it? There's an entire history of using pendulums
to measure altitude, and latitude -- and time or distance: at some
locations on earth a 1 meter pendulum is so close to a 1 second
beat there was consideration to define the meter that way.
Some articles on gravity, earth tides, and pendulum clocks:
John Allen writes:
> Hi Tom - what is HSN?
Horological Science Newsletter, http://www.hsn161.com
It's a collection of people who still find precision pendulum clocks
fascinating, a specific strain of the time nut disease. It's a small
group (officially Chapter #161, Horological Science) of the larger:
National Association of Watch & Clock Collectors, http://www.nawcc.org
More information about the time-nuts