Groups > sci.physics.relativity > #371497

Re: On length contraction

From	wugi <brol@brol.be>
Newsgroups	sci.physics.relativity
Subject	Re: On length contraction
Date	2015-12-06 18:18 +0100
Organization	Aioe.org NNTP Server
Message-ID	<n41qns$4ga$1@speranza.aioe.org> (permalink)
References	<480b34d8-19e3-4189-a293-4cf298956389@googlegroups.com>

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kenseto schreef op 5/12/2015 om 16:55:
> On length contraction according to SR:
> 1. A meter stick M is moving wrt observers A, B and C.
>
> 2. A predicts (SRians claim "Measures") the contracted length of M is 1/gamma_am.
>
> 3. B predicts (SRians claim "Measures") the contracted length of M is 1/gamma_bm.
>
> 4. C predicts (SRians claim "Measures") the contracted length of M is 1/gamma_cm.
>
> It is obvious that M cannot have different contracted material lengths as
>predicted by the different observers.

Says who? It can and does have them very well.

>That means that length contraction in SR is not material (not real).

Yes it is (real material).

 >So what is length contraction in SR? SRians
>claim that length contraction is the geometric projection of the meter stick
>onto the x-axis of observer's coordinate system.

It is that too. Besides real and material.

What appears to bother most "SRian-bashers", is the seeming 
incompatibility worded by stating that "if (1) A < B, then (2) B < A 
can't be".
This stems from the lack of realisation that different events are to be 
considered in establishing (1) and (2). For your case for instance: in 
defining and comparing lengths of M in A, and again of A in M. (And of 
B; and C...).
Once one does realise so, it is easily understood that the studied 
"moving object" itself (its set of world lines) is not affected nor 
changed by this or that measurement. It is only the sets of "events to 
be chosen" for this or that measurement that are different.
And their differences turn out to be nicely mutual, so yes
A=B/gamma and B'=A'/gamma
are not contradictary but obvious.
http://home.pi.be/~pin12499/MySRT/LorentzObjects.PNG

Now, if for its measurement a moving object is not affected, "identical" 
objects moving wrt each other *are* affected in that they could not 
"instantly become each other". During the acceleration process that 
makes one object approach the other's frame, a physical change has to 
happen, which pertains to the physical reality of length contraction 
(and time dilation).
Some classical paradoxes use (or abuse:) this feature.

-- 
guido
http://home.pi.be/~pin12499/paratwin.htm

Thread

On length contraction kenseto <setoken@att.net> - 2015-12-05 07:55 -0800
  Re: On length contraction Maciej Woźniak <mlwozniak@wp.pl> - 2015-12-05 18:40 +0100
  Re: On length contraction kenseto <setoken@att.net> - 2015-12-05 15:49 -0800
  Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-05 22:39 -0600
    Re: On length contraction Maciej Woźniak <mlwozniak@wp.pl> - 2015-12-06 10:28 +0100
    Re: On length contraction alsor@interia.pl - 2015-12-06 05:40 -0800
      Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-06 09:03 -0600
        Re: On length contraction alsor@interia.pl - 2015-12-09 02:37 -0800
      Re: On length contraction fuller.david@hotmail.com - 2015-12-06 08:14 -0800
        Re: On length contraction fuller.david@hotmail.com - 2015-12-06 08:27 -0800
          Re: On length contraction fuller.david@hotmail.com - 2015-12-06 10:37 -0800
    Re: On length contraction kenseto <setoken@att.net> - 2015-12-06 06:21 -0800
      Re: On length contraction rotchm <rotchm@gmail.com> - 2015-12-06 08:19 -0800
        Stephane Baune tries to correct Ken Shito and, in the process, embarrasses himself "Dono," <sa_ge@comcast.net> - 2015-12-07 08:35 -0800
  Re: On length contraction Thomas Heger <ttt_heg@web.de> - 2015-12-06 08:24 +0100
    Re: On length contraction Poutnik <poutnik4nntp@gmail.com> - 2015-12-06 08:41 +0100
    Re: On length contraction kenseto <setoken@att.net> - 2015-12-06 07:06 -0800
    Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-06 09:20 -0600
      Re: On length contraction Thomas Heger <ttt_heg@web.de> - 2015-12-06 21:43 +0100
        Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-07 09:46 -0600
    Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-06 15:09 -0600
      Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-07 09:49 -0600
  Re: On length contraction rotchm <rotchm@gmail.com> - 2015-12-06 08:10 -0800
    Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-07 10:01 -0600
      Re: On length contraction rotchm <rotchm@gmail.com> - 2015-12-07 08:28 -0800
        Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-07 10:57 -0600
          Re: On length contraction mlwozniak@wp.pl - 2015-12-07 22:58 -0800
          Re: On length contraction Thomas Heger <ttt_heg@web.de> - 2015-12-08 08:44 +0100
          Re: On length contraction kenseto <setoken@att.net> - 2015-12-08 14:33 -0800
            Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-08 17:56 -0600
            Re: On length contraction moroney@world.std.spaamtrap.com (Michael Moroney) - 2015-12-10 20:07 +0000
              Re: On length contraction kenseto <setoken@att.net> - 2015-12-10 13:13 -0800
                Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-10 17:19 -0600
                Re: On length contraction moroney@world.std.spaamtrap.com (Michael Moroney) - 2015-12-11 02:45 +0000
                Re: On length contraction kenseto <setoken@att.net> - 2015-12-10 21:11 -0800
                Re: On length contraction rotchm <rotchm@gmail.com> - 2015-12-11 06:57 -0800
                Re: On length contraction kenseto <setoken@att.net> - 2015-12-11 19:20 -0800
                Re: On length contraction moroney@world.std.spaamtrap.com (Michael Moroney) - 2015-12-11 19:55 +0000
                Re: On length contraction Plexippus Kritikos <plexik@laertesegidio.org> - 2015-12-11 23:25 +0000
                Re: On length contraction kenseto <setoken@att.net> - 2015-12-11 19:25 -0800
                Re: On length contraction pnalsing@gmail.com - 2015-12-11 19:48 -0800
                Re: On length contraction pnalsing@gmail.com - 2015-12-13 14:33 -0800
                Re: On length contraction moroney@world.std.spaamtrap.com (Michael Moroney) - 2015-12-12 17:27 +0000
                Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-14 10:12 -0600
                Re: On length contraction kenseto <setoken@att.net> - 2015-12-10 21:08 -0800
                Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-11 08:04 -0600
    Re: On length contraction kenseto <setoken@att.net> - 2015-12-08 14:26 -0800
      Re: On length contraction Plexippus Kritikos <plexik@laertesegidio.org> - 2015-12-08 22:40 +0000
        Re: On length contraction kenseto <setoken@att.net> - 2015-12-09 06:50 -0800
          Re: On length contraction alsor@interia.pl - 2015-12-09 09:06 -0800
      Re: On length contraction rotchm <rotchm@gmail.com> - 2015-12-09 09:47 -0800
        Re: On length contraction Plexippus Kritikos <plexik@laertesegidio.org> - 2015-12-09 18:11 +0000
          Re: On length contraction Sam Wormley <swormley1@gmail.com> - 2015-12-09 12:32 -0600
            Re: On length contraction alsor@interia.pl - 2015-12-09 11:18 -0800
            Re: On length contraction kenseto <setoken@att.net> - 2015-12-10 06:57 -0800
        Re: On length contraction kenseto <setoken@att.net> - 2015-12-10 06:46 -0800
  Re: On length contraction wugi <brol@brol.be> - 2015-12-06 18:18 +0100
    Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-06 12:35 -0600
      Re: On length contraction wugi <brol@brol.be> - 2015-12-06 21:58 +0100
        Re: On length contraction wugi <brol@brol.be> - 2015-12-06 22:31 +0100
        Re: On length contraction Tom Roberts <tjroberts137@sbcglobal.net> - 2015-12-07 10:16 -0600
      Re: On length contraction John Gogo <jfgogo22@yahoo.com> - 2015-12-06 13:08 -0800
        Re: On length contraction John Gogo <jfgogo22@yahoo.com> - 2015-12-06 14:26 -0800
          Re: On length contraction John Gogo <jfgogo22@yahoo.com> - 2015-12-06 14:38 -0800
          Re: On length contraction John Gogo <jfgogo22@yahoo.com> - 2015-12-06 15:39 -0800
  Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-06 15:07 -0600
    Re: On length contraction benj <none@gmail.com> - 2015-12-14 02:21 -0500
      Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-14 10:44 -0600
        Re: On length contraction alsor@interia.pl - 2015-12-14 08:59 -0800
        Re: On length contraction kenseto <setoken@att.net> - 2015-12-14 09:05 -0800
          Re: On length contraction alsor@interia.pl - 2015-12-14 09:48 -0800
          Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-14 12:18 -0600
            Re: On length contraction kenseto <setoken@att.net> - 2015-12-15 05:49 -0800
              Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-15 08:21 -0600
                Re: On length contraction mlwozniak@wp.pl - 2015-12-15 23:29 -0800
                Re: On length contraction kenseto <setoken@att.net> - 2015-12-16 07:04 -0800
                Re: On length contraction Odd Bodkin <bodkinodd@gmail.com> - 2015-12-16 09:14 -0600

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