Re: is free-fall an inertial frame?

[Bob Sciamanda <trebor@VELOCITY.NET>]

----- Original Message -----
From: Stefan Jeglinski <jeglin@4PI.COM>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, August 18, 1999 1:16 AM
Subject: Re: is free-fall an inertial frame?

> 2)  . . .
> Yes, I seem to understand the GR situation much better (oddly in my
> estimation). I wonder why in searching for an inertial frame in the
> Newtonian response, free-falling frames are ignored or avoided (see
> my response to John Denker's post). There would not appear to be the
> same basis for "avoidance" of a free-fall as for a rotating frame,
> when trying to find an inertial frame.
> Stefan Jeglinski

Let me re-emphasize (ad nauseam) that within the Newtonian model an object
in free fall (near the earth) is accelerating.  If you (the observer) also
go into free fall, you will not measure this acceleration because YOU are
"co-accelerating".  (I re-re-emphasize also that it is presumed that you
have already discovered the law of universal gravitation, which tells you
that the object in free fall [which you may now observe to be at rest] is
accelerating relative to inertial frames.)

Addendum query:  The earth is in free fall in the gravitational field of
the solar system. Could a Newtonian scheme make this an inertial frame and
also make an inertial frame out of an apple falling to the earth's
surface?

Bob

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor

Quine, Willard Van Orman:
Just as the introduction of the irrational numbers ... is a convenient
myth [which] simplifies the laws of arithmetic ... so a physical scheme of
physical objects is [likewise] a convenient myth, simpler than the literal
truth and yet containing that literal truth as a scattered part.
In J. Koenderink, Solid Shape, Cambridge Mass. MIT Press, 1990.