Re: Yes, Paul?Re: Equivalence my ass! Re: Well, Hobba? Re: A. Newtonian Invariance vs SR-cult fraud and corruption (Rev B)

From: Bill Hobba (bhobba_at_rubbish.net.au)
Date: 10/24/04 

Date: Sun, 24 Oct 2004 05:34:12 GMT

"Mike" <eleatis@yahoo.gr> wrote in message
news:9c1b39be.0410231519.7062b3e0@posting.google.com...
> "Bill Hobba" <bhobba@rubbish.net.au> wrote in message
news:<dnhed.35776$5O5.2466@news-server.bigpond.net.au>...
> > "eleaticus" <eleaticus@bellsouth.net> wrote in message
> > news:aBfed.43875$pi7.23026@bignews4.bellsouth.net...
> > >
> > > "Paul Draper" <pdraper@yahoo.com> wrote in message
> > > news:74768d2d.0410221336.6341411@posting.google.com...
> > > > daryl@atc-nycorp.com (Daryl McCullough) wrote in message
> > > news:<clap4r01dmn@drn.newsguy.com>...
> > >
> > > > > So the conclusion of your demonstration is observably false.
> > > >
> > > > There's another demonstration that shows this beautifully. You and a
> > > > buddy go to the playground with a basketball and get on one of those
> > > > rotatable turntables that the kids spin on until they get nauseous.
> > > > Once you've gotten up to speed, you and your buddy stand at opposite
> > > > points on the perimeter of the turntable and toss the ball to each
> > > > other. The path of a thrown ball in this rotating frame is something
> > > > that has to be seen to be believed! With practice, you can throw the
> > > > ball directly across the turntable and catch it yourself!
> > >
> > > I told y'all how to do it, how to show that the relative velocity wrt
to
> > an
> > > accelerating system has nothing to do with the question of whether the
> > > inertial obect actually travels a straight line as defined by the
> > continual
> > > comparison of 'milestone' coordinates: B'-A' = C'-B'.
> >
> > Get real. When the turntable is not rotating push the ball and
(neglecting
> > air resistance and gravity) it travels in a straight line relative to
you
> > and a Cartesian coordinate system say painted on the turntable and a
pole
> > where you are standing - experimental fact. Spin the turntable and
relative
> > to exactly the same coordinate system the ball no longer travels at
constant
> > velocity in a straight line - again experimental fact. Thus how the
ball
> > behaves when it is thrown are different. The whole issue boils down to
what
> > one counts as a law of physics - it is obvious that free particles no
longer
> > travel at constant velocity (but see my other comments below) so if you
> > count that as a law of physics (and most would - it is Newton's first
law of
> > motion) then the laws of physics are different. However what Einstein
says
> > with the principle of general invariance is that is not how we should
> > express laws of nature - we should write then in covariant form so they
are
> > the same in any coordinate system. Thus you either say - Newton's first
law
> > of motion is not a valid law because it is not expressed conveniently or
you
> > say that the laws motion are different in accelerated frames. Take your
> > pick - each is ok by me - although I generally opt for the second one.
> >
> > But care is also required - Newton's first law of motion is really
> > circular - it says a free particle moves at constant velocity unless
acted
> > on by a force. We release the ball - we find nothing else in the system
> > acting on it (remember we are neglecting air resistance and gravity) so
> > according to our intuitive idea of free particle it is not acted on by a
> > force so should move at constant velocity - so we conclude the frame is
not
> > inertial. Or we can say - hey it is not moving at constant velocity so
is
> > not free thus Newton's first law still holds. Newton's first law is
seen to
> > be rather vacuous (force free means moving at constant velocity - so
what do
> > we count as force free?) - it is in fact circular so it is quite
reasonable
> > to say it is not a law worth saving. We would be better of basing our
> > definition of inertial frame and formulation of the laws of motion on
the
> > principle of equivalence and the symmetries of an inerital frame - that
way
> > we never run into problems. But it is a bit sad we need such an
advanced
> > theory to get around these issues - which is why I generally opt for the
> > second option and say the laws of physics are not the same in
accelerated
> > frames. However I am happy with either view as long as the person makes
it
> > clear which view they are advocating and use it consistently. In fact
if
> > Newton's laws were scrapped in teaching mechanics (see
> > http://www.eftaylor.com/pub/FmaAJPguest5.pdf - ie it was all based on
the
> > PLA) and we define an inertial frame by its symmetry properties then
IMHO le
> > ss problems would arise and we would all be better off. The laws of
physics
> > would be the same in all frames right from the outset - conservation of
> > momentum, energy etc would be seen for what they are - simply a
reflection
> > of the underlying symmetry of an inertial frame.
> >
> > Bill
> >
>
> You do not know what you're talking about. Now I am convinced. So is
> your prof. Taylor. Hidding the problem does not eliminate it.

Taylor is a well respected physicist, world renewed for his textbooks on
relativity written with Wheeler - an acknowledged master of relativity. If
Wheeler and Taylor do not know what he is talking about no one does.

>
> Tell me something. How would you teach the LPA?
>

What is the LPA? Do you mean PLA - the principle of least action.?

> as a 'a priori truth',

The only 'a priori truth' is logic - and even there debate exists.

> as an empirical proposition or as a mathematical model in a
> constructivism sense.

I would simply point out, as Taylor does, that an alternative formulation of
QM is Feymans sum over histories approach. The little arrow that turns in
this explanation cancels all paths except those where the exponent s in e^is
does not vary - this s is in fact the Lagrangeian. Another method as
espoused in Landau - Mechanics and Classical Mechanics, Quantum Mechanics
and Field Theory by Amnon Katz is to take the PLA as foundational and
develop mechanics from it. QM is seen to result from what is known as
saddle point integration (page 40-41 of the reference byAmnon Katz). In
this formulation one can introduce the powerful Noether theorem. But this is
a problem for educators and choosing a style suitable for the kinds of
students they have, their background and interests. I am simply noting the
circularity one has with Newton's first law disappears in such an approach.

> Is it a Platonic, Formalistic or Constructivist
> approach to physics?

This is physics not mathematics - so the answer is none of the above or more
specifically who gives a ****. I leave such to the person who writes the
book. In Taylor's case his style has been described as 'pedagogically
sound' but informal and 'pokey'. As Feynman says in his lectures there is
no standard answer to such questions - one chooses the teaching style
depending on the material - just like he choose different styles in his
famous lectures.

>
> Do you think the PLA would make sense in lieu of Newton's Laws?
>

Do you ever ensure brain is engaged before opening mouth or do you always
sprout off about what you obviously know nothing about? Their is a well
known mathematical theorem saying the two approaches are equivalent. The
Lagrnagian approach is better because it generalizes beyond classical
mechanics, has a closer relationship to QM, and allows wielding of Noethers
powerful theorem.

> Do you
> want to taylor physics teachings so they can be understood by the
> average moron who pays for education? Do you think such approach is
> for the benefit of society?

I do not think in such terms. I think in terms of trying it out on a small
scale and seeing what happens - which is exactly what is occurring. What we
need in education is less perception on what must be done and more choice
for the student. Teaching physics by the PLA as advocated by Taylor is part
of such a process. If it paves successful it will expand - if not it will
go the way of the dinosaurs and students will wait for graduate school be
exposed to it.

>
> Are you trying to set the foundations for the next round of dark ages?
> Don't you feel any shame at all?
>

It is obvious you understand very little about physics at all.

Bill

>
> Mike

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