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Re: Centrifugal force



Without the functioning rocket, he would know when the earth was removed!
Re-think this!

-Bob


Bob Sciamanda trebor@velocity.net
Dept of Physics
Edinboro Univ of PA http://www.velocity.net/~trebor
Edinboro, PA (814)838-7185
-----Original Message-----
From: Hugh Logan <hlogan@ix.netcom.com>
To: phys-l@atlantis.uwf.edu <phys-l@atlantis.uwf.edu>
Date: Friday, May 01, 1998 11:44 PM
Subject: Re: Centrifugal force


Hugh Logan wrote:

Chuck Britton wrote:

Next question. Let's ignore the 'slight bump' but keep in mind that
the
rocket DOES have a finite size. If our experiments are accurate
enough can
we not measure that two falling objects in the rocket will move
closer to
each other because of the non-uniformity of a 'real' gravitational
field,
than they would when the acceleration is 'caused' by the rocket
blast?

I'm familiar with the word 'local' used to describe the principle of
equivalence and GR, but is there a fundemental arguement that
forbids our
experimentally distinguishing between the divergent gravitational
field and
the uniform acceleration of the rocket??

I don't think there is anything, in principle, that would prevent
measuring the tidal effect other than whether or not the precision of
the instrumentation used was adequate to do so -- whether or not the
rocket ship was large enough in relation to the effects of the
divergence of the gravitational field of the earth to allow such
effects
to be detected.

As an afterthought, would it make any difference in the outcome of
Chuck's proposed experiment if the unpowered rocket were resting on the
launch pad (a launch pad one meter higher to be exact) instead of
hovering? A lot of fuel could be saved that way. I would not expect it
to make any difference whether the rocket was supported by the contact
force of the launch pad or the thrust of the rocket engine.

Hugh Logan