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Re: [Phys-L] another DIY relativity experiment




On 2016, May 20, , at 13:04, John Denker <jsd@av8n.com> wrote:

On 05/20/2016 11:45 AM, Bob Sciamanda wrote:

the rate of some changes are, by their physics, already dependent on
the strength of local gravity. For instance, a clock whose period is
determined by a pendulum would not even work on the ship which is in
gravity free space! So the above statement opens the question of how
it applies to phenomena whose physics of time evolution includes a
dependence on gravity apart from any relativistic effects?

The short answer is that metrologists stopped depending on
pendulum clocks a long time ago, circa 1736.


https://snr.org.uk/sea-trial-john-harrisons-chronometer-1736/ <https://snr.org.uk/sea-trial-john-harrisons-chronometer-1736/>




I think John is confused about the use of pendula clocks and balance wheel (torsion pendula) clocks. The better land pendula clocks are considerably better than all seafaring chronometers.


Until Marrison observatories used only pendulum clocks, e.g. Rieflers, Shortts, et alia.


bc amateur horologist.

p.s. Before Harrison (>50 years), Huygens invented a chronometer, but inadequate. And cosmonauts use a pendulum to mass themselves.