Re: The Elevator in Free Fall

Jonathan Thornburg [remove -color to reply] il 21/12/2024 09:27:44 ha
scritto:

...
Now let's look at the same system from a GR perspective, i.e., from a
perspective that gravity isn't a force, but rather a manifestation of
spacetime curvature.  In this perspective it's most natural to measure
accelerations relative to *free-fall*, or more precisely with respect
to a *freely-falling local inertial reference frame* (FFLIRF).  An
FFLIRF is just a Newtonian IRF in which a fixed coordinate position
(e.g., x=y=z=0) is freely falling.

Can we define the interior space of the elevator as "local" or is it
too big?

If it is too big, how big must it be to be considered "local"?

If it is shown that there are real forces inside the free-falling
elevator, can we still consider this reference system inertial?

Are tidal forces real?

Do we mean by "freely falling bodies" only those that fall in the very
weak gravitational field of the Earth or also those that fall in any
other gravitational field, such as that of Jupiter or a black hole?

Luigi Fortunati.