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From: jlg@lanl.ARPA (Jim Giles)
Newsgroups: net.physics,net.origins
Subject: Re: Bogus physics reamplified
Message-ID: <424@lanl.ARPA>
Date: Thu, 13-Mar-86 21:05:35 EST
Article-I.D.: lanl.424
Posted: Thu Mar 13 21:05:35 1986
Date-Received: Sat, 15-Mar-86 22:17:23 EST
References: <368@ihnet.UUCP> <2057@jhunix.UUCP> <2874@sjuvax.UUCP> <446@3comvax.UUCP>
Reply-To: jlg@a.UUCP (Jim Giles)
Distribution: net
Organization: Los Alamos National Laboratory
Lines: 42
Keywords: general relativity, justifying assertions, name-calling
Xref: watmath net.physics:3939 net.origins:2953

In article <446@3comvax.UUCP> michaelm@3comvax.UUCP (Michael McNeil) writes:
>Returning to Ken's original point, which started off this whole series
>of articles, in the above reference Bertrand Russell writes as follows:  
>
>	But in the modern theory the question between Copernicus and
>	his predecessors is merely one of convenience; all motion
>	is relative, and there is no difference between the two
>	statements:  `the earth rotates once a day' and `the heavens
>	revolve about the earth once a day.'  The two mean exactly the
>	same thing, just as it means the same thing if I say a certain
>	length is six feet or two yards.  Astronomy is easier if we
>	take the sun as fixed than if we take the earth, just as
>	accounts are easier in decimal coinage.  {Signet, pp. 13-14}

Whatever Bertrand Russell's qualifications in mathematics are, no one
would ever accuse him of being a great physicist.  One of the paramount
features of General Relativity is that the laws of physics should
appear the same in ALL reference frames.  In a reference frame which
is fixed with respect to the average motion of the nearby stars, those
stars all appear to be traveling with low (relatively) velocities.  In a
'reference frame' which is fixed to the spinning Earth, the nearby stars
appear to be traveling MUCH FASTER than the speed of light. (Consider A-
Centauri: radius of 'orbit' around Earth is 4.2 light years, it 'orbits'
once per day, total distance traveled per day is 2*4.2*PI light years or
about 26 light years per day.) The consequences of stars being tachyons in
one 'frame' and not being tachyons in the other would cause the observers
in the two frames to come to different conclusions about the laws of
physics in Earth local space (that is, the only way to reconcile the two
observations is to assume that there is a space-time singularity between
the two observers, but when they go to look they won't find one).

The bottom line is that rotation is LOCALLY discernable and is therefore
NOT a property of Einstein's reference frames (whether they are lorentz
frames or not).  One way of locally measuring rotation is with a foucault
pendulum (which you even mentioned).  Meanwhile ALL Einstein frames are
LOCALLY indistinguishable from lorentz frames.

For the definition of 'frame' and 'local' I suggest you read the first few
chapters of MTW ('Gravitation') again.  I just did - fascinating stuff!

J. Giles
Los Alamos