Re: Inertial Frames

From: Sam Wormley (swormley1_at_mchsi.com)
Date: 10/11/04 

Date: Mon, 11 Oct 2004 00:20:09 GMT

Starfish wrote:
> Could someone please provide me with a clear formal definition of what
> is meant by "the homogeity of space and time" and "the isotropy of
> space"? I am particularly interested in the formal definition, not a
> physical explanation. My confusion lies in the fact that my
> interpretations of some basic concepts of classical mechanics are
> contradictory:
>
> 1.) An inertial reference frame is defined as a frame with the
> properties of homogeneity of time and space and isotropy of space.
> 2.) Isotropy means invariance under rotation; homogeneity means
> invariance under translation.
> 3.) There exist noninertial reference frames which the equations of
> motion are invariant under rotations and translations.
>
> Clearly, these ideas cannot all be simultaneously correct. Where's my
> error? Please do not reply with some treatise on special relativity;
> in this question I am simply interested in the foundations of
> classical mechanics.

Isotropy
   http://scienceworld.wolfram.com/astronomy/Isotropy.html

Homogeneity
   http://scienceworld.wolfram.com/astronomy/Homogeneity.html