Re: A Geometrical Proof of the Non-invariance of the Spacetime In terval

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

This may be obvious to others, but I'll keep at it.

It appears to me that the problem is that you think person F' can not
determine the city in which they are located at any particular time.  Which
as your intuition is telling you is patently absurd.  And *is not* the
implication of SR.

Sure his stomach's coordinates are always zero, but the spatial coordinates
of breakfast as measured by F' is a different question than what city
breakfast occured in and F' is fully capable of answering either question.

F' can easily determine in what city he ate breakfast.  His stomach is the
origin of F' and he eats breakfast at t' = 0.  So the coordinate location of
breakfast is F's origin, as is lunch.  But the city in which breakfast
occured is simply determined by F' noticing that LA's coordinates are also
at the origin at breakfast (hence breakfast is in LA).  But San Diego's
coordinates are at the origin when he eats lunch, therefore he concludes
that he at lunch in the city of San Diego.

Joel

> -----Original Message-----
> From: David Rutherford [mailto:drutherford@SOFTCOM.NET]
> Sent: Monday, January 20, 2003 1:01 PM
> To: PHYS-L@lists.nau.edu
> Subject: Re: A Geometrical Proof of the Non-invariance of the
> Spacetime
> Interval
>
>
> "RAUBER, JOEL" wrote:
> > > > Let me pose a slightly different question.  Its 10am
> according to
> > > > F' several hours after breakfast and several hours before lunch
> > > > according to F'
> > > >
> > > > In what city does F' say his breakfast occured?
> > >
> > > According to SR, F' _always_ (at and after the occurrence of
> > > breakfast) considers breakfast to have occurred wherever F' (the
> > > origin of F') happens to be at the time.
> >
> > I infer from what you say above that F' considers breakfast
> to occur in LA,
> > since his origin was in LA at the time of breakfast. n'est
> pas? Or have I
> > misinterpreted what you say?
>
> If that were the case, F' would not measure zero distance between
> breakfast and lunch at the time of lunch. SR definitely says
> that F' will measure zero distance between the two, in the example I
> posed. F' makes the measurement of the distance between breakfast and
> lunch at the time of lunch. At that time, he places one end
> of his tape
> measure at the place he considers breakfast to have occurred (his
> origin), and the other end at the place he considers lunch to
> occur (his
> origin). Therefore, he determines that there is zero distance between
> breakfast and lunch.
>
> --
> Dave Rutherford
> "New Transformation Equations and the Electric Field Four-vector"
> http://www.softcom.net/users/der555/newtransform.pdf
>
> Applications:
> "4/3 Problem Resolution"
> http://www.softcom.net/users/der555/elecmass.pdf
> "Action-reaction Paradox Resolution"
> http://www.softcom.net/users/der555/actreact.pdf
> "Energy Density Correction"
> http://www.softcom.net/users/der555/enerdens.pdf
> "Proposed Quantum Mechanical Connection"
> http://www.softcom.net/users/der555/quantum.pdf