Author: Edward Green Date: Nov 28, 2006 02:59
> Bill Hobba wrote:
>> "fitz" yahoo.com> wrote in message
>>> When can we use special relativity?
>> When no, or at the most only weak, gravitational fields are present.
> Does gravity change retarded potential or the speed of light?
We can use SR locally in any old case, provided "local" is defined as
"not on such scales of time, distance and precision where SR begins to
fail"; in other words, we can use it, except when we can't. ;-)
Hmm... though what does that say about laboratories not in free fall?
I dropped my pencil... oops! Gravitational effect! Can't use SR!
Perhaps we can continue to use SR in some situations with significant
gravitational effects (like falling pencils), under an approximation of
Newtonian gravity; i.e., where a gravitational force is added by hand.