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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Laser to the Moon, was: next lunar eclipse
From: Frank Reed CT
Date: 2004 May 9, 16:51 EDT
From: Frank Reed CT
Date: 2004 May 9, 16:51 EDT
Brooke C wrote:
"There are optical retro reflectors on the moon used with lasers to range the moon."
Of course they don't work too well with handheld laser pointers... <g>
By the way, those corner cube reflectors were originally proposed as a test of general relativity (though they have many other uses, too). A competing theory of gravitation, the Brans-Dicke theory, indicated that there should be subtle variations in the Moon's orbit if "GR" was not quite right. As it turned out after analyzing the reflections for several years, the prediction of general relativity is accurate. This seems worth mentioning in 2004 because there is yet another test of general relativity just about to begin in orbit (after FORTY YEARS of planning). It has the slightly retro name "Gravity Probe B", and you can read about it here:
http://einstein.stanford.edu
It is primarily designed to detect a "whirlpool in space" --the slight "swirling" of space itself generated by the rotation of the Earth.
Frank R
[X] Mystic, Connecticut
[ ] Chicago, Illinois
"There are optical retro reflectors on the moon used with lasers to range the moon."
Of course they don't work too well with handheld laser pointers... <g>
By the way, those corner cube reflectors were originally proposed as a test of general relativity (though they have many other uses, too). A competing theory of gravitation, the Brans-Dicke theory, indicated that there should be subtle variations in the Moon's orbit if "GR" was not quite right. As it turned out after analyzing the reflections for several years, the prediction of general relativity is accurate. This seems worth mentioning in 2004 because there is yet another test of general relativity just about to begin in orbit (after FORTY YEARS of planning). It has the slightly retro name "Gravity Probe B", and you can read about it here:
http://einstein.stanford.edu
It is primarily designed to detect a "whirlpool in space" --the slight "swirling" of space itself generated by the rotation of the Earth.
Frank R
[X] Mystic, Connecticut
[ ] Chicago, Illinois
