Re: [Phys-L] weightlessness

[Hugh Haskell <haskellh@verizon.net>]

At 11:56 AM -0700 6/27/12, John Denker wrote:
> In all cases, g is frame-dependent.  This is required by Einstein's
> principle of equivalence.
>
>   a) In the frame of the space station, g *is* zero.
>
>   b) In the frame of the earth, g in the vicinity of the space station
>      is on the order of 9.8 m/s/s.
>
> Talking about "the" g field without specifying which frame is being
> used is ill-posed.
>
> Contradicting one ill-posed statement and replacing it with another is
> not an improvement.
>   http://www.av8n.com/physics/weight.htm

OK, I'll give you that. This more or less answers my question, but in 
a way I neglected to anticipate. I am wondering if the orbital 
influence on the space station is detectable, or is it, like that on 
the earth pretty much negligible. From a pedagogical POV, I realize 
that I neglected to specify my frame of reference, and that was 
wrong, but I also think that it isn't all that terrible to assume 
that our "default" FOR is usually the earth, and assume that for most 
practical purposes we can also assume it to be inertial, granting the 
obvious exception when one deal with coriolis effects, which can 
sometimes be surprisingly noticeable, even aside from the weather.

Hugh
--
Hugh Haskell
mailto:hugh@ieer.org
mailto:haskellh@verizon.net

I have been wondering for a long time why some of our own defense 
officials do not
put more emphasis on finding a good substitute for oil and worry less 
about where
more oil is to come from.  Our people are ingenious. New discoveries 
are all around
us, and when we have to make them, we nearly always do.

						Eleanor Roosevelt
						February 13, 1948