At 12:51 AM 3/20/5, Grimer wrote: >At 06:32 am 20-03-05 +0000, you wrote: >>The Foucault Pendulum is a fascinating thing. >>I suppose the best place to observe one is at >>the poles where the complete rotation can be >>seen. Indeed, in summer time at the north pole >>it would be even more weird since it would be >>turning in time with the sun.
Actually it would be turning in sidereal time, maintaining fixed relationship with the stars. [snip] >Back to the drawing board. ;-) [snip] A gyroscope very well gimballed in all axes and oriented in the equatorial plane should work (though not as a pendulum). A nifty thing about that in the old days is it could have replaced an accurate clock as the means of determining longitude. A good gyro, combined with an accurate lunar ephemieris to be used for periodic gyro calibration, could have been used to achieve fairly accurate navigation and mapping. The technological problems then "merely" consist of achieving frictionless bearings and a nearly perfect vacuum. Regards, Horace Heffner
