From: fortunati.luigi@gmail.com   
      
   Julio Di Egidio sabato 07/05/2022 alle ore 15:00:52 ha scritto:   
   >>> A free-falling brick is an inertial frame?=20   
   >   
   > A free-falling brick is *in* "an" inertial frame.  Which more precisely   
   > means that we can find an inertial frame in which the brick is in   
   > uniform motion, then just a special case is an inertial frame in=20   
   > which the brick is at rest, and and even more special case is the   
   > frame in which the brick is at rest at the origin of space.  And we   
   > might call that last one "the brick's own frame", because there is   
   > indeed something "privileged" about it as far as that brick is   
   > concerned: OTOH, though, notice that the fact that the brick is in   
   > *free-fall* requires no frame to state or verify at all, it's altogethe=   
   r   
   > a *true* physical property that can be verified *locally*.   
      
   How small must this be "locally"?   
      
   As small as a brick? A half brick? A tenth of a brick?   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)