Re: [Phys-l] Weightless

[Jack Uretsky <jlu@hep.anl.gov>]

Hi all-
	There are probably better places to look for practical uses of
GMm/r^{2}, or its vector equivalent, than the world of commerce.  Both 
NIST (at Boulder, CO) and U. Wash., Seattle, (Eotwash project) have, for 
the past several years, been making precision measurements of G by 
doing refined versions of the Cavendish experiment.  I have heard 
presentations from members of both of these groups.
	The experiments are sensitive to accumulations of large 
accumulations of matter, such as mountains (which are plentiful, both in 
Washington and Colorado), so corrections must be calculated and accounted 
for in the experiments.  I understand that there are web sites for both of 
these experimental groups; I've not investigated them.  But that is where 
the current state of the art of calculating gravitational fields is to be 
found.  I doubt that swimming pool contractors would be useful as 
consultants.
				Regards,
					Jack


On Wed, 22 Nov 2006, Robert Carlson wrote:

> John,
>
> If I were to hire a contractor to build a pool, I
> doubt that the definition of weight would come into
> our conversation.  I certainly would ask for
> references and visit pools they have already built.
> Good luck with your quest.
>
> Bob Carlson
>
>
> On 11/21/2006 09:39 PM, Robert Carlson wrote:
>
> > please name one
> > engineer you know of that has been fired because
> they
> > studied Hibbeler or Beer and Johnston and used their
> > definition of weight.
>
> 1) Please name one engineer who was ever silly enough
> to
> use the formula
>                  - G M
>    "g_vector" = -------- r_vector       (???)
>                    r^3
>
> for any precision terrestrial engineering application.
>
> 2) Suppose you hired contractors to install an
> in-ground
> swimming pool in your back yard.  Suppose they wanted
> to
> build it so that the rim was "horizontal" in the sense
> of
> being perpendicular to the "g_vector" defined above.
> Would
> *you* fire them, or not?
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