Re: When can we use special relativity?


Eric Gisse wrote:
Sue... wrote:
Edward Green wrote:
Sue... wrote:
Bill Hobba wrote:
"fitz" <zeusrdx@xxxxxxxxx> 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. ;-)

That's the sort of non answer I'd expect from Hobba or Roberts...but
then
I posed the question to Hobba so I'll give you a B+ on pinch hitting.
;-)


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.

The question is not when can you *abuse* SR. It is important
that we don't attach inertial effects where the term "uniform motion"
is used in the 1920 paper. The 1923 Gothenburg lecture offer some
insight why. The Tajmar / de Matos experiment is another clue.

a) The Tajmar/de Matos experiment has yet to be published anywhere
other than the arXiv and an ESA press release. For such groundbreaking
work, some folks certaintly are dragging their feet.

Indeed they are!
<< As of November 20, we are well into Phase III of the data
analysis, which we expect to be concluded by late February,
2007. Whereas in Phases I and II, the focus was on individual
gyro performance, during Phase III, the data from all four gyros
is being integrated over the entire experiment. The results of
this phase will be both individual and correlated changes in
gyro spin axis orientation covering the entire 50-week experimental
period for all four gyros. During this final analysis phase, we are
continuing to pursue both geometric and algebraic interpretations
of the data, which is enabling us to improve the accuracy of the
results. >>
http://einstein.stanford.edu/

Sue...




b) That is GR, the subject is about SR. Learn the difference.

[snip word salad and irrelevant links]

.

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