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Re: Car decelerates...

From Mike Fontenot <mlfasf@comcast.net>
Newsgroups sci.physics.relativity
Subject Re: Car decelerates...
Date 2016-01-28 09:46 -0700
Organization A noiseless patient Spider
Message-ID <56AA45E1.7020002@comcast.net> (permalink)
References <69476ed3-b8bc-4a33-b883-6e6e9de59188@googlegroups.com>

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On 1/27/16 8:42 PM, Jon Price wrote:
> Drivers body moves forward.
>
>  From cars reference frame, what causes forward body movement?
>
> A gravitational field?
>

Using a frame of reference in which the observer, who's perspective is 
being given, is perpetually located at the spatial origin does NOT 
require that the observer consider himself to be unaccelerated. This 
same thing happens in the classic twin "paradox", at the (often assumed) 
instantaneous turnaround when the rocket-twin fires his rocket.  It is 
perfectly OK (and vastly simpler and less contorted) for the rocket-twin 
to contend that his rocket causes him to suddenly accelerate (and to 
essentially instantaneously change his velocity wrt the 
perpetually-inertial home-twin).  The alternate GR-equivalent 
explanation is that the rocket-twin contends that he is perpetually 
inertial, and that he uses his rocket only to counteract the sudden 
gravitational field that is somehow momentarily mysteriously switched on 
everywhere, and which causes everyone and everything ELSE to suddenly 
accelerate. Those other people FEEL no acceleration, because gravity 
works on each tiny piece of a person's body, and no internal stresses in 
their bodies are produced, because none of those pieces are acted on by 
any other force.  The rocket-twin DOES feel a force, from his rocket 
firing, because that force does NOT act directly on each of his body 
pieces, but only directly on a few of those pieces (like those pieces in 
contact with the seat of his spacecraft), thus producing internal 
stresses in his body.

As an explanation of the twin "paradox", the GR-equivalent explanation 
is clumsy, unnecessary, and needlessly confusing.  Its value was really 
only as a consistency check on the general relativity theory of 
gravitation (and on some of its early results), and as an illustration 
of the equivalence principle.

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame

   "Accelerated Observers in Special Relativity", PHYSICS ESSAYS, 
December 1999, p629.

   All you ever need to know about the twin "paradox".

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Thread

Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:42 -0800
  Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 04:44 +0100
    Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 19:48 -0800
      Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 15:28 +1100
        Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 22:58 -0800
          Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 19:57 +1100
            Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 01:07 -0800
              Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-28 22:08 +1100
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 03:51 -0800
                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 10:53 +1100
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 19:31 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 06:40 +0100
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:29 -0800
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 22:57 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:08 +0100
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:18 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:24 +0100
                Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:25 -0800
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-29 10:19 -0800
                Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-29 13:30 -0600
                Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 12:21 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:48 +0100
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-31 13:55 +0100
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-31 13:16 -0800
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 00:35 -0800
                Re: Car decelerates... Polikwaptiwa <polikw@polikwamail.org> - 2016-01-30 16:32 +0000
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-30 18:02 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:19 +0100
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:23 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-29 08:28 +0100
                Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 23:39 -0800
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 09:56 +0100
                Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-30 10:09 +0100
                Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 11:34 +0100
                Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:20 -0800
                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-29 23:12 +1100
                Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-29 12:33 +0000
                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:16 +1100
                Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 12:25 +0100
                Re: Car decelerates... Sylvia Else <sylvia@not.at.this.address> - 2016-01-30 22:34 +1100
                Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-30 13:45 +0100
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 04:42 -0800
                Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-29 06:17 -0800
                Re: Car decelerates... mlwozniak@wp.pl - 2016-01-29 06:23 -0800
                Re: Car decelerates... Maciej Woźniak <mlwozniak@wp.pl> - 2016-01-29 06:17 +0100
      Re: Car decelerates... Melzzzzz <mel@zzzzz.com> - 2016-01-28 13:37 +0100
      Re: Car decelerates... moroney@world.std.spaamtrap.com (Michael Moroney) - 2016-01-28 19:33 +0000
  Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:08 -0800
    Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:28 -0800
      Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 20:34 -0800
        Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:50 -0800
        Re: Car decelerates... mlwozniak@wp.pl - 2016-01-27 23:00 -0800
          Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-27 23:34 -0800
            Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-28 07:23 -0800
            Re: Car decelerates... Odd Bodkin <bodkinodd@gmail.com> - 2016-01-28 09:59 -0600
              Re: Car decelerates... mlwozniak@wp.pl - 2016-01-28 22:27 -0800
            Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 16:49 +0000
            Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:29 +0100
      Re: Car decelerates... rotchm <rotchm@gmail.com> - 2016-01-27 20:53 -0800
      Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 07:47 +0100
        Re: Car decelerates... Juan Sebastián <jseb@montserrat.info> - 2016-01-28 18:22 +0000
          Re: Car decelerates... Poutnik <poutnik4nntp@gmail.com> - 2016-01-28 22:31 +0100
  Re: Car decelerates... Koobee Wublee <koobee.wublee@gmail.com> - 2016-01-27 23:59 -0800
    Re: Car decelerates... Jon Price <jonelwoodprice@gmail.com> - 2016-01-28 00:19 -0800
  Re: Car decelerates... jamesl51165@gmail.com - 2016-01-28 08:18 -0800
  Re: Car decelerates... Mike Fontenot <mlfasf@comcast.net> - 2016-01-28 09:46 -0700

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