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Groups > sci.physics.relativity > #363251 > unrolled thread

SR is just another name for LET

Started bykenseto <setoken@att.net>
First post2015-09-06 09:18 -0700
Last post2015-09-16 11:24 -0700
Articles 20 on this page of 151 — 17 participants

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  SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 09:18 -0700
    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-06 09:26 -0700
      Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-06 12:53 -0400
      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 11:38 -0700
        Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-06 15:25 -0700
        Re: SR is just another name for LET "Dono," <sa_ge@comcast.net> - 2015-09-06 17:16 -0700
          Re: SR is just another name for LET kenseto <set...@att.net> - 2015-09-07 01:39 +0000
          Re: SR is just another name for LET moroney@world.std.spaamtrap.com (Michael Moroney) - 2015-09-07 02:44 +0000
            Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-06 19:56 -0700
    Re: SR is just another name for LET alsor@interia.pl - 2015-09-06 10:00 -0700
      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 11:50 -0700
        Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-06 15:24 -0400
          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 12:47 -0700
        Re: SR is just another name for LET alsor@interia.pl - 2015-09-06 13:25 -0700
    Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-06 18:33 -0500
      Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-06 17:52 -0600
        Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 17:55 -0700
          Re: SR is just another name for LET alsor@interia.pl - 2015-09-06 18:47 -0700
        Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-06 22:19 -0500
          Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-07 09:18 -0600
            Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 08:39 -0700
              Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-07 10:05 -0600
                Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 09:34 -0700
                  Pretender Stephane Baune strikes again. "Dono," <sa_ge@comcast.net> - 2015-09-07 12:10 -0700
                Re: SR is just another name for LET Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-09-07 21:48 +0200
              Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 12:37 -0400
                Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 09:53 -0700
                  Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 13:13 -0400
                    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 10:24 -0700
                      Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 14:42 -0400
                        Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 13:06 -0700
                          Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 16:50 -0400
                            Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 14:23 -0700
              Re: SR is just another name for LET wugi <brol@brol.be> - 2015-09-12 17:07 +0200
                Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-12 14:08 -0500
                  Re: SR is just another name for LET Frances Espinosa <franesp@portio.org> - 2015-09-12 20:07 +0000
                    Re: SR is just another name for LET JanPB <filmart@gmail.com> - 2015-09-12 13:50 -0700
                      Re: SR is just another name for LET Frances Espinosa <franesp@portio.org> - 2015-09-12 21:25 +0000
                      Re: SR is just another name for LET Maciej Woźniak <mlwozniak@wp.pl> - 2015-09-13 10:21 +0200
                    Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-12 19:45 -0500
                      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-13 06:00 -0700
                        Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-13 09:14 -0500
                          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-13 09:12 -0700
                            Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-13 16:34 -0700
                            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-14 12:50 -0500
                              Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-14 16:20 -0500
                                Re: SR is just another name for LET Maciej Woźniak <mlwozniak@wp.pl> - 2015-09-14 23:26 +0200
                                Re: SR is just another name for LET Frances Espinosa <franesp@portio.org> - 2015-09-14 22:36 +0000
                                Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-15 07:01 -0700
                                  Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-15 09:11 -0500
                                    Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-15 08:00 -0700
                                      Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-15 10:15 -0500
                                        Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-15 13:40 -0700
                                          Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-15 16:21 -0500
                                            Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-16 06:28 -0700
                                              Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-16 11:15 -0500
                                                Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-16 11:36 -0700
                                                  Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-16 16:22 -0700
                                                    Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-16 19:03 -0500
                                                      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-17 08:18 -0700
                                                        Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-17 10:32 -0500
                                                          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-17 08:43 -0700
                                                            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-17 12:16 -0500
                                                    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-16 19:04 -0700
                                                      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-17 08:20 -0700
                                                    Re: SR is just another name for LET alsor@interia.pl - 2015-09-17 07:09 -0700
                                                Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-16 16:21 -0700
                                      Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-15 08:30 -0700
                                Re: SR is just another name for LET alsor@interia.pl - 2015-09-15 14:43 -0700
                              Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-15 06:51 -0700
                                Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-15 09:10 -0500
                          Re: SR is just another name for LET Maciej Woźniak <mlwozniak@wp.pl> - 2015-09-13 20:49 +0200
                          Re: SR is just another name for LET Koobee Wublee <koobee.wublee@gmail.com> - 2015-09-14 00:20 -0700
                      Re: SR is just another name for LET Frances Espinosa <franesp@portio.org> - 2015-09-13 14:37 +0000
                  Re: SR is just another name for LET alsor@interia.pl - 2015-09-13 11:17 -0700
                  Re: SR is just another name for LET wugi <brol@brol.be> - 2015-09-13 21:15 +0200
                    Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-13 15:46 -0500
                      Re: SR is just another name for LET alsor@interia.pl - 2015-09-14 09:17 -0700
                  Re: SR is just another name for LET Koobee Wublee <koobee.wublee@gmail.com> - 2015-09-14 00:16 -0700
                    Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-14 03:53 -0400
                      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-14 07:15 -0700
                        Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-14 11:12 -0400
                          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-14 10:18 -0700
                            Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-14 16:37 -0400
                    Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-14 12:55 -0500
                      Re: SR is just another name for LET alsor@interia.pl - 2015-09-14 11:13 -0700
                      Re: SR is just another name for LET Maciej Woźniak <mlwozniak@wp.pl> - 2015-09-14 22:08 +0200
                      Re: SR is just another name for LET Koobee Wublee <koobee.wublee@gmail.com> - 2015-09-14 23:25 -0700
                Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-12 14:03 -0700
                  Re: SR is just another name for LET wugi <brol@brol.be> - 2015-09-15 18:42 +0200
                    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-15 11:46 -0700
                      Re: SR is just another name for LET wugi <brol@brol.be> - 2015-09-16 16:10 +0200
                        Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-16 08:15 -0700
            Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-07 10:38 -0700
              Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 12:55 -0700
            Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-08 10:23 -0500
              Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-08 09:29 -0700
              Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-08 10:44 -0600
                Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-08 10:11 -0700
                  Stephane Baune poser strikes again "Dono," <sa_ge@comcast.net> - 2015-09-08 11:30 -0700
                  Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-08 12:50 -0600
                    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-08 12:23 -0700
                      Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-08 13:46 -0600
                        Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-08 13:02 -0700
                          Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-08 15:27 -0600
                            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-09 09:10 -0500
                              Re: SR is just another name for LET alsor@interia.pl - 2015-09-09 08:05 -0700
                                Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-10 23:52 -0500
                                  Re: SR is just another name for LET alsor@interia.pl - 2015-09-11 08:33 -0700
                                    Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-11 13:53 -0500
                                      Re: SR is just another name for LET alsor@interia.pl - 2015-09-11 14:11 -0700
                        Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-10 23:50 -0500
                          Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-11 11:02 -0600
                      Re: SR is just another name for LET alsor@interia.pl - 2015-09-08 13:26 -0700
                      Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-10 23:39 -0500
                        Re: SR is just another name for LET JanPB <filmart@gmail.com> - 2015-09-10 23:00 -0700
                Re: SR is just another name for LET Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-09-08 20:47 +0200
                  Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-08 14:23 -0500
                    Re: SR is just another name for LET Mike Fontenot <mlfasf@comcast.net> - 2015-09-08 15:36 -0600
            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-08 13:55 -0500
          Re: SR is just another name for LET alsor@interia.pl - 2015-09-07 10:58 -0700
            Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 14:56 -0400
              Re: SR is just another name for LET alsor@interia.pl - 2015-09-07 12:29 -0700
                Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 16:39 -0400
                  Re: SR is just another name for LET alsor@interia.pl - 2015-09-08 10:05 -0700
      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-06 17:35 -0700
        Re: SR is just another name for LET Tom Roberts <tjroberts137@sbcglobal.net> - 2015-09-06 22:22 -0500
          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-07 06:21 -0700
            Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-07 09:35 -0400
              Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-07 06:42 -0700
            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-08 13:38 -0500
            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-08 13:39 -0500
              Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-09 08:36 -0700
                Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-09 10:50 -0500
                  Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-09 20:23 -0700
                    Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-09 20:30 -0700
                    Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-10 08:01 -0500
                      Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-11 09:53 -0700
                        Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-11 12:07 -0500
                          Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-11 10:54 -0700
                          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-11 14:24 -0700
                            Re: SR is just another name for LET alsor@interia.pl - 2015-09-11 14:48 -0700
                            Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-11 16:48 -0500
                              Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-12 06:10 -0700
                                Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-13 22:13 -0500
                        Re: SR is just another name for LET rotchm <rotchm@gmail.com> - 2015-09-11 10:45 -0700
        Re: SR is just another name for LET Odd Bodkin <bodkinodd@gmail.com> - 2015-09-08 13:35 -0500
          Re: SR is just another name for LET kenseto <setoken@att.net> - 2015-09-09 08:41 -0700
    SR is just another name for LET fuller.david@hotmail.com - 2015-09-16 06:50 -0700
      Re: SR is just another name for LET kefischer <emoneyjoe@iglou.com> - 2015-09-16 10:59 -0400
        Re: SR is just another name for LET fuller.david@hotmail.com - 2015-09-16 11:24 -0700

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#363489

FromMike Fontenot <mlfasf@comcast.net>
Date2015-09-08 12:50 -0600
Message-ID<55EF2E01.6020407@comcast.net>
In reply to#363477
On 9/8/15 11:11 AM, rotchm wrote:
> On Tuesday, September 8, 2015 at 12:44:05 PM UTC-4, Mike_Fontenot wrote:
>
>> In LET, the Lorentz equation derivation
>> doesn't assume anything about what the moving frame concludes about the
>> ether frame.  But that then means that IF we can invert those two
>> equations, and get X and T as functions of x and t, then those inverse
>> equations will tell us what a moving (inertial) frame will conclude
>> about the ether frame.
>
> You might think so, but if you look closely, all conspires that you can never solve
> for the ether's X and T. This is why, "we dont need the ether frame" as Einstein
> pointed (and as pointed out by Poincare, before Einstein!) out.  We only have access
> to (x,t) via measurements.  You cant find the v thus there exist infinite possibilities
> for X and T.
>

What I was trying to get at, was that I THINK Lorentz arrived at the 
Lorentz equations WITHOUT assuming at the outset that any two inertial 
observers who were moving relative to one another would each come to the 
SAME conclusions about the other observer's clocks and rods.  I may be 
wrong about that ... it's been a LONG time since I read about how 
Lorentz arrived at those equations.  But I think I do remember reading 
that Lorentz didn't get it right the first time ... as I remember it, he 
initially included length contraction, but not time dilation.  It seems 
clear that, in THAT form, the equations wouldn't have had the property 
that the inverse of the equations were essentially the same as the 
equations themselves ... so at that stage, he wouldn't have thought each 
of two relatively-moving inertial observers would come to the same 
conclusions about the other observer's position and time coordinates. 
On the other hand, Einstein DID assume reciprocity (along with the 
assumption that any light pulse would always be measured to have the 
same speed c) to drive the Lorentz equations, without having to assume 
the existence of an ether.  So I suspect their derivations were 
different, even though the ultimate equations which resulted from those 
derivations were exactly the same.  I think it may have been a complete 
surprise to Lorentz that the inverse of his equations would be 
essentially the same as the original equations themselves, and therefore 
that observers moving wrt the ether would think that it was the 
ether-frame clocks and rods that were the ones which were slowed and 
contracted.  And I think Lorentz may have (at least initially) thought 
that it should be possible to identify the ether frame.  But I may well 
be wrong about that, and about the history of Lorentz' derivation of his 
equations.

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame
   All you ever need to know about the twin "paradox".

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#363493

Fromrotchm <rotchm@gmail.com>
Date2015-09-08 12:23 -0700
Message-ID<f29e02d6-a16b-491b-bf04-7d47c9223308@googlegroups.com>
In reply to#363489
On Tuesday, September 8, 2015 at 2:50:45 PM UTC-4, Mike_Fontenot wrote:
 
> What I was trying to get at, was that I THINK Lorentz arrived at the 
> Lorentz equations WITHOUT assuming at the outset that any two inertial 
> observers who were moving relative to one another would each come to the 
> SAME conclusions about the other observer's clocks and rods.  

What Lorentz sought out to do was to find eqs that will leave Maxwell's eqs invariant; iow, all inertial observers should/must obtain the same Maxwell's eqs. Lorentz almost found the correct eqs...Poincare corrected him and gave him the eqs, now called Lorentz eqs. But Lorentz and Poincare had differing views on what the variables actually meant. Poincare realized that they simply represented the values obtained by measurements, by the *conventional measurement procedures*. His 1898 treatise in "the measure of time" goes on into this and where he introduces the beginnings of relativity...

> as I remember it, he initially included length contraction, 

Also called the Lorentz-Fitzgerald contraction. 

> but not time dilation.  It seems 
> clear that, in THAT form, the equations wouldn't have had the property 
> that the inverse of the equations were essentially the same as the 
> equations themselves ... so at that stage, he wouldn't have thought each 
> of two relatively-moving inertial observers would come to the same 
> conclusions about the other observer's position and time coordinates.

Indeed. The time dilation appeared when he (or Poincare) found the transformations that kept Maxwells eqs the same.

> On the other hand, Einstein DID assume reciprocity (along with the 
> assumption that any light pulse would always be measured to have the 
> same speed c) 

Yes. Note that that postulate is not necessary since the Maxwells eqs imply it. 
And there is reciprocity in LET if one considers that the Maxwells eqs must be the same for all inertial observers. 

> to drive the Lorentz equations, without having to assume 
> the existence of an ether.  

Correct. Einstein showed that based on the relativity principle alone (and/or with the light postulate), we did not need of an ether nor of the Maxwell eqs or other stuff to get the Lorentz eqs. 

> So I suspect their derivations were different, 

Correct. Totally different. 

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#363499

FromMike Fontenot <mlfasf@comcast.net>
Date2015-09-08 13:46 -0600
Message-ID<55EF3B19.7080403@comcast.net>
In reply to#363493
On 9/8/15 1:23 PM, rotchm wrote:
>
>  Note that that postulate is not necessary since the Maxwells eqs imply it.
> And there is reciprocity in LET if one considers that the Maxwells eqs must
> be the same for all inertial observers.
>

I've often heard that, but I've never understood why that is true.  When 
I studied Maxwell's equations (admittedly, a LONG time ago), I never 
could see that the issue of "with respect to what" was ever addressed, 
nor did I see reciprocity addressed anywhere.

I'd really appreciate some help in understanding how reciprocity and the 
equivalence of all inertial frames was inherent in Maxwell's equations. 
  I vaguely remember reading somewhere that the way magnetic fields 
enter the equations doesn't make sense without the idea that the 
equations are exactly the same (with the same value for "c") in all 
inertial frames, but I've never understood that. (I think that the most 
recent look I've had at Maxwell's equations have been in the "Feynman 
Lectures" books).

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame
   All you ever need to know about the twin "paradox".

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#363502

Fromrotchm <rotchm@gmail.com>
Date2015-09-08 13:02 -0700
Message-ID<e43b411c-d6b8-4fe5-9c0c-48d0669f6df6@googlegroups.com>
In reply to#363499
On Tuesday, September 8, 2015 at 3:46:36 PM UTC-4, Mike_Fontenot wrote:
> On 9/8/15 1:23 PM, rotchm wrote:
> >
> >  Note that that postulate is not necessary since the Maxwells eqs imply it.
> > And there is reciprocity in LET if one considers that the Maxwells eqs must
> > be the same for all inertial observers.
> >
> 
> I've often heard that, but I've never understood why that is true.  When 
> I studied Maxwell's equations (admittedly, a LONG time ago), I never 
> could see that the issue of "with respect to what" was ever addressed, 
> nor did I see reciprocity addressed anywhere.

Good recognition. True that that is seldom pointed out. Maxwell found those equations by analyzing past exp's and of his own. Since all those exp's satisfied those eqs, and that those exp were done at random times/orientation throughout history, then those eqs were independent of where and when they were performed. IOW, they were found to be valid for all observers. So, the quantities in the Max.eqs are wrt the observer (the given lab frame).

> equivalence of all inertial frames was inherent in Maxwell's equations. 

Yes, by construction one may say. 

>   I vaguely remember reading somewhere that the way magnetic fields 
> enter the equations doesn't make sense without the idea that the 
> equations are exactly the same (with the same value for "c") in all 
> inertial frames, but I've never understood that. 

Not sure what you are referring to...

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#363515

FromMike Fontenot <mlfasf@comcast.net>
Date2015-09-08 15:27 -0600
Message-ID<55EF52BD.9090909@comcast.net>
In reply to#363502
On 9/8/15 2:02 PM, rotchm wrote:
>
> Yes, by construction one may say.
>

Perhaps its is true that, even if Maxwell's equations were derived (or 
formulated) to agree with experimental observations in just one 
particular lab's inertial reference frame, the equations once obtained 
can be shown to be invariant under a general transformation to any other 
inertial frame.

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame
   All you ever need to know about the twin "paradox".

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#363552

FromOdd Bodkin <bodkinodd@gmail.com>
Date2015-09-09 09:10 -0500
Message-ID<mspeka$3uc$1@speranza.aioe.org>
In reply to#363515
On 9/8/2015 4:27 PM, Mike Fontenot wrote:
> On 9/8/15 2:02 PM, rotchm wrote:
>>
>> Yes, by construction one may say.
>>
>
> Perhaps its is true that, even if Maxwell's equations were derived (or
> formulated) to agree with experimental observations in just one
> particular lab's inertial reference frame, the equations once obtained
> can be shown to be invariant under a general transformation to any other
> inertial frame.
>

But not invariant under a Galilean transformation between inertial frames.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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#363559

Fromalsor@interia.pl
Date2015-09-09 08:05 -0700
Message-ID<178afe19-9832-49b0-b7a0-1d1c2259091f@googlegroups.com>
In reply to#363552
W dniu środa, 9 września 2015 16:10:33 UTC+2 użytkownik Odd Bodkin napisał:
> On 9/8/2015 4:27 PM, Mike Fontenot wrote:
> > On 9/8/15 2:02 PM, rotchm wrote:
> >>
> >> Yes, by construction one may say.
> >>
> >
> > Perhaps its is true that, even if Maxwell's equations were derived (or
> > formulated) to agree with experimental observations in just one
> > particular lab's inertial reference frame, the equations once obtained
> > can be shown to be invariant under a general transformation to any other
> > inertial frame.
> >
> 
> But not invariant under a Galilean transformation between inertial frames.

The waves perception is invariant under that transform:

x' = k(x-vt);
t' = t;

because that is fully equivalent to the Lorentz Transform.

simply:
r' = c't = kc(t - xv/c^2);
and is replaced - reinterpreted to the ct' in the SR model, 
so this nithing changes because:

r' = c't = ct' = r';

any interpretation has no effect on the math... it's just:
r' = r'.

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#363739

FromTom Roberts <tjroberts137@sbcglobal.net>
Date2015-09-10 23:52 -0500
Message-ID<doqdnc7MKKGFw2_InZ2dnUU7_8xi4p2d@giganews.com>
In reply to#363559
On 9/9/15 9/9/15   10:05 AM, alsor@interia.pl wrote:
> The waves perception is invariant under that transform:
> x' = k(x-vt);
> t' = t;
> because that is fully equivalent to the Lorentz Transform.

Why do you just make stuff up and claim it is true?

ESPECIALLY when it is so blatantly obvious that you are wrong?


Tom Roberts

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#363772

Fromalsor@interia.pl
Date2015-09-11 08:33 -0700
Message-ID<a3c79b6f-1971-454d-a93b-dcecab998e49@googlegroups.com>
In reply to#363739
W dniu piątek, 11 września 2015 06:52:42 UTC+2 użytkownik tjrob137 napisał:
> On 9/9/15 9/9/15   10:05 AM, alsor@interia.pl wrote:
> > The waves perception is invariant under that transform:
> > x' = k(x-vt);
> > t' = t;
> > because that is fully equivalent to the Lorentz Transform.
> 
> Why do you just make stuff up and claim it is true?
> 
> ESPECIALLY when it is so blatantly obvious that you are wrong?

Your naive claims are equivalent to say:
Lorentz, Poincare and even Einstein was wrong.

The:
x' = k(x-vt);
t' = t;

is just the Lorentz transform, but in a classical form,
because the LET is a classical theoery -
there is no the spacetime, four-vectors Minkowski algebra.

The LET basis is/was just that:

I. any material body contracts under motion (in the ether frame);
what is described by:
x' = ...

II. there is nothing...
because all the rest is just derived...
from classical physics/math.
including the clock slow down effect;
there is no time dilation, but the slow-down,
because that and therefore I stil wrote,
like stupid idiot: t = t' = inv.


And the famous historical Lorentz time transform:
t' = ...;
it's just an artificial Lorentzs time concept;
a suplementary thing only - it's irrelevant at all in this theory...

The sense of such art. time is that:
if we use such time (as a convention of time),
then we don't bother about our motion - 
we just can assume we are always stationary (in the ether frame).

So, in this way we arrived just to the SR basis - a model, convention;

LET --some simplifications, conventions--> SR;

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#363799

FromTom Roberts <tjroberts137@sbcglobal.net>
Date2015-09-11 13:53 -0500
Message-ID<au6dncZR2vuRvm7InZ2dnUU7_8xi4p2d@giganews.com>
In reply to#363772
On 9/11/15 9/11/15 - 10:33 AM, alsor@interia.pl wrote:
> The:
> x' = k(x-vt);
> t' = t;
> is just the Lorentz transform, but in a classical form,

No, it is NOT.

I repeat: why do you just make stuff up and claim it is true?

ESPECIALLY when it is so blatantly obvious that you are wrong?


Tom Roberts

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#363815

Fromalsor@interia.pl
Date2015-09-11 14:11 -0700
Message-ID<e32e0f43-7f1e-40a6-8140-b076e42d37c5@googlegroups.com>
In reply to#363799
W dniu piątek, 11 września 2015 20:53:03 UTC+2 użytkownik tjrob137 napisał:
> On 9/11/15 9/11/15 - 10:33 AM, alsor@interia.pl wrote:
> > The:
> > x' = k(x-vt);
> > t' = t;
> > is just the Lorentz transform, but in a classical form,
> 
> No, it is NOT.

It is and exactly.
 
> I repeat: why do you just make stuff up and claim it is true?

Do you really aspire to disprove the whole classical math, my stupid babe?
 
> ESPECIALLY when it is so blatantly obvious that you are wrong?

Relly? then show taht insetead of talking.

Oh! these stupid babes... :)

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#363738

FromTom Roberts <tjroberts137@sbcglobal.net>
Date2015-09-10 23:50 -0500
Message-ID<doqdnc_MKKEwwG_InZ2dnUU7_8ydnZ2d@giganews.com>
In reply to#363499
On 9/8/15 9/8/15   2:46 PM, Mike Fontenot wrote:
> I'd really appreciate some help in understanding how reciprocity and the
> equivalence of all inertial frames was inherent in Maxwell's equations.

But it ISN'T.

Maxwell wrote his equations in the unique frame in which the aether was at rest. 
Note that he has several more equations and fields, which are not used today; 
some are related directly to the aether frame.

Everybody expected to apply a Galilean transform to his equations to get 
equations valid on earth. But that turned out not to work, creating the major 
puzzle I discussed in the article I posted in this thread a few minutes ago.

 From a basis of mathematics and ways of solving particle differential 
equations, Poincare' knew to look for their invariance group, and he found it.

 From a basis of physical intuition, Einstein figured out how the ME transform. 
Remarkably, they found the same answer (at the time that was rather amazing, but 
in retrospect it is obvious).



 From a theoretical standpoint, one can write equations in a specified frame 
(e.g. the aether frame), and specify the transforms to apply them in other 
frames (e.g. the Galilean transforms). The problem is that this gives a theory 
that is incompatible with many experiments and observations. Maxwell's 
derivation of his equations was inherently in the aether frame, but they were 
found to be valid on the (moving) earth, yielding a conundrum. Poincare' and 
Einstein resolved it in different but related ways, and Einstein's approach 
(based on symmetry) has become the foundation of all modern fundamental theories 
of physics.


Tom Roberts

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#363782

FromMike Fontenot <mlfasf@comcast.net>
Date2015-09-11 11:02 -0600
Message-ID<55F3090A.6070300@comcast.net>
In reply to#363738
On 9/10/15 10:50 PM, Tom Roberts wrote:
> On 9/8/15 9/8/15   2:46 PM, Mike Fontenot wrote:
>> I'd really appreciate some help in understanding how reciprocity and the
>> equivalence of all inertial frames was inherent in Maxwell's equations.
> [...]

Thanks to Tom for his responses, and also thanks to rotchm for his 
responses ... both were helpful.  It sounds like I could profit by 
reading some Poincare'.

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame
   All you ever need to know about the twin "paradox".

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#363507

Fromalsor@interia.pl
Date2015-09-08 13:26 -0700
Message-ID<044c595a-89fb-452a-9c36-3d576afffebe@googlegroups.com>
In reply to#363493
W dniu wtorek, 8 września 2015 21:23:52 UTC+2 użytkownik rotchm
> 
> Einstein showed that based on the relativity principle alone (and/or with the light postulate), we did not need of an ether nor of the Maxwell eqs or other stuff to get the Lorentz eqs. 

He just showed, proposed some simplified version, ie. a model.

LET is not an algebraic trifle, like SR is,
but it's a foramally correct classical theory.

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#363736

FromTom Roberts <tjroberts137@sbcglobal.net>
Date2015-09-10 23:39 -0500
Message-ID<buqdne5oUbVxx2_InZ2dnUU7_8ydnZ2d@giganews.com>
In reply to#363493
On 9/8/15 9/8/15   2:23 PM, rotchm wrote:
> On Tuesday, September 8, 2015 at 2:50:45 PM UTC-4, Mike_Fontenot wrote:
>> What I was trying to get at, was that I THINK Lorentz arrived at the
>> Lorentz equations WITHOUT assuming at the outset that any two inertial
>> observers who were moving relative to one another would each come to the
>> SAME conclusions about the other observer's clocks and rods.
>
> What Lorentz sought out to do was to find eqs that will leave Maxwell's eqs
> invariant;

His initial quest was not for invariance, as that concept had not really been 
fully developed, and its importance was completely unknown back then.

Lorentz was looking to find a transform from the ether frame to the earth frame 
that resulted in the Maxwell's equations that had survived experimental tests. 
But as any earth (moving) frame must work, we now recognize he was indeed 
looking for invariance.

	Poincare' and Einstein provided the initial incentive for
	invariance as we know it today. Not Lorentz (though he provided
	important contributions).


> iow, all inertial observers should/must obtain the same Maxwell's
> eqs. Lorentz almost found the correct eqs...Poincare corrected him and gave
> him the eqs, now called Lorentz eqs. But Lorentz and Poincare had differing
> views on what the variables actually meant. Poincare realized that they
> simply represented the values obtained by measurements, by the *conventional
> measurement procedures*. His 1898 treatise in "the measure of time" goes on
> into this and where he introduces the beginnings of relativity...

Yes. And then Einstein completely upset the applecart with his then-outrageous 
notion that the transforms actually described the world and measurements of it, 
and that the coordinates in the "moving frame" represent what clocks and rulers 
at rest in that frame actually measure.


>> as I remember it, he initially included length contraction,
> Also called the Lorentz-Fitzgerald contraction.
>> but not time dilation.  It seems clear that, in THAT form, the equations
>> wouldn't have had the property that the inverse of the equations were
>> essentially the same as the equations themselves

But Lorentz was not looking for inverse equations at all -- he was looking 
aether => earth, and the inverse makes no sense in the worldview of the time.

But once one recognizes invariance, then it also becomes clear that the 
transform equations must form a group, and that implies the inverse transform 
must be the same as the forward transform.


>... so at that stage, he
>> wouldn't have thought each of two relatively-moving inertial observers
>> would come to the same conclusions about the other observer's position and
>> time coordinates.

Yes. "reciprocity" has no place in the worldview of Lorentz, because the aether 
frame is fundamentally QUITE different from whichever moving frame the earth 
happens to be at rest in.

	I mean Lorentz in 1895-1904 while he was developing LET.
	Later, he embraced Einstein's notions to a considerable degree.


>> On the other hand, Einstein DID assume reciprocity (along with the
>> assumption that any light pulse would always be measured to have the same
>> speed c)

Yes. "Reciprocity" is essentially his Principle of Relativity, and your 
parenthetical is a consequence of his two postulates (it is NOT one of them).


> Yes. Note that that postulate is not necessary since the Maxwells eqs imply
> it.

Then one must replace Einstein's second postulate with the postulate that 
Maxwell's equations are laws of nature. While that is surely what Einstein was 
thinking, it is a MUCH more complicated assumption than his actual second postulate.

	REMEMBER THE CONTEXT. In 1905 a MAJOR puzzle was the
	incompatibility between Newtonian mechanics (with its Galilean
	transforms) and Maxwell's equations (which were of course
	expressed in the unique aether frame). That is, when one applies
	a Galilean transform to the ME, aether-frame to earth-frame, one
	obtains equations which are NOT consistent with experiments and
	observations. This is the puzzle that Lorentz, Poincare', and
	many others were attempting to address, 1890-1905. Einstein's
	first postulate was a central part of NM, and his second
	postulate was right in line with then-current aether theories.
	So no knowledgeable reader in 1905 would have trouble with
	either of his postulates; his resolution of that major puzzle
	was remarkable and innovative. And it's rather amazing that it
	has turned out to be so important to modern theoretical physics!


> And there is reciprocity in LET if one considers that the Maxwells eqs
> must be the same for all inertial observers.

Not really. In LET the frame moving faster relative to the ether is PHYSICALLY 
contracted and dilated MORE than a slower frame; it is pure happenstance that 
the Lorentz transforms imply "time dilation" and "length contraction" for the 
slower frame when observed from the faster frame [#].

	Of course TODAY this is not "happenstance", but rather a
	direct consequence of the derivation of SR.

	[#] As I keep stressing, TD and LC are primarily consequences
	of the difference in simultaneity between the frames, and the
	measurement procedure used.


> Einstein showed that based on the relativity principle alone (and/or
> with the light postulate), we did not need of an ether nor of the Maxwell eqs
> or other stuff to get the Lorentz eqs.
>
>> So I suspect their derivations were different,
>
> Correct. Totally different.

Yes.


Tom Roberts

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#363741

FromJanPB <filmart@gmail.com>
Date2015-09-10 23:00 -0700
Message-ID<c3f242d5-011b-46ef-ae96-c9da48bbef98@googlegroups.com>
In reply to#363736
On Thursday, September 10, 2015 at 9:39:11 PM UTC-7, tjrob137 wrote:
> On 9/8/15 9/8/15   2:23 PM, rotchm wrote:
> > 
> > iow, all inertial observers should/must obtain the same Maxwell's
> > eqs. Lorentz almost found the correct eqs...Poincare corrected him and gave
> > him the eqs, now called Lorentz eqs. But Lorentz and Poincare had differing
> > views on what the variables actually meant. Poincare realized that they
> > simply represented the values obtained by measurements, by the *conventional
> > measurement procedures*. His 1898 treatise in "the measure of time" goes on
> > into this and where he introduces the beginnings of relativity...
> 
> Yes. And then Einstein completely upset the applecart with his then-outrageous 
> notion that the transforms actually described the world and measurements of it, 
> and that the coordinates in the "moving frame" represent what clocks and rulers 
> at rest in that frame actually measure.

Einstein mentions this, as quoted by R. S. Shankland(*): "I asked Professor Einstein how
long he had worked on [special relativity] before 1905. He told me that he had started
at age 16 and worked for ten years [...] He abandoned many fruitless attempts, "until
at last it came to me that time was suspect!""

(*) Am. J. Phys. 31, 47 (1963)

--
Jan

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#363490

FromThomas 'PointedEars' Lahn <PointedEars@web.de>
Date2015-09-08 20:47 +0200
Message-ID<1696771.bjEZ1HktUM@PointedEars.de>
In reply to#363474
Mike Fontenot wrote:

> I've also thought more about WHY the M/M results were consistent with
> LET,

You have it backwards.  Lorentz ether theory (1892, 1895) has been proposed 
*after* the Michelson–Morley experiments (1881, 1889) were performed, in 
order to explain the null results.

The problem with the LET, even the revised variant, by Poincaré, is not that 
it cannot be experimentally confirmed; but that, as SR shows, it makes 
extraneous assumptions, “many of which later turned out to be incorrect”.  
You do not need a luminiferous ether if you only make the following two 
initial assumptions:

  1. The principle of relativity applies to inertial frames.
  2. The speed of light is constant.

Those were not entirely new assumptions at the time: Galilei and Newton had 
already shown that mechanics works the same in all inertial frames, and 
previous experiments had shown the speed of light to be equal and constant 
in all media with equal optical density.

See also: <https://en.wikipedia.org/wiki/Lorentz_ether_theory>


PointedEars
-- 
Q: What did the nuclear physicist order for lunch?  
A: Fission chips.

(from: WolframAlpha)

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#363492

FromTom Roberts <tjroberts137@sbcglobal.net>
Date2015-09-08 14:23 -0500
Message-ID<Pamdnfnxv6ErqHLInZ2dnUU7_8ydnZ2d@giganews.com>
In reply to#363490
On 9/8/15 9/8/15 - 1:47 PM, Thomas 'PointedEars' Lahn wrote:
> You do not need a luminiferous ether if you only make the following two
> initial assumptions:
>
>    1. The principle of relativity applies to inertial frames.
>    2. The speed of light is constant.

Indeed, one does not need the second assumption, either. The PoR and the 
definition of inertial frames admit only three transformation groups among 
inertial frames, and some very basic experiments and observations single out the 
Lorentz group for modeling the world we inhabit (the other two groups are the 
Galilei group and the Euclid group in 4d).

	Einstein identified some additional, implicit assumptions
	in 1907:
	  * clocks and rulers have no memories (in that their tick
	    rate and length do not depend on their history)
	  * space is isotropic and homogeneous
	  * time is homogeneous
	And we should add one from 1915:
	  * applies only in a region small enough so any spacetime
	    curvature does not affect measurements significantly

This approach has the advantage of keeping separate things separate -- E&M and 
light are not mixed into relativity, which is really a theory about geometry.


Tom Roberts

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#363516

FromMike Fontenot <mlfasf@comcast.net>
Date2015-09-08 15:36 -0600
Message-ID<55EF54DC.3050401@comcast.net>
In reply to#363492
On 9/8/15 1:23 PM, Tom Roberts wrote:
> On 9/8/15 9/8/15 - 1:47 PM, Thomas 'PointedEars' Lahn wrote:
>> You do not need a luminiferous ether if you only make the following two
>> initial assumptions:
>>
>>    1. The principle of relativity applies to inertial frames.
>>    2. The speed of light is constant.
>
> Indeed, one does not need the second assumption, either. The PoR and the
> definition of inertial frames admit only three transformation groups
> among inertial frames, and some very basic experiments and observations
> single out the Lorentz group for modeling the world we inhabit (the
> other two groups are the Galilei group and the Euclid group in 4d).

I don't know enough group theory to understand that proof (I HAVE seen 
it previously), but I can see how the requirement that the inertial 
reference frame transformation be equal to its inverse is a very 
restrictive and powerful requirement that probably can only be satisfied 
by a very small number of transformations.

> [...]
> This approach has the advantage of keeping separate things separate --
> E&M and light are not mixed into relativity, which is really a theory
> about geometry.
>

That certainly is a very desirable state of affairs.

-- 
   https://sites.google.com/site/cadoequation/cado-reference-frame
   All you ever need to know about the twin "paradox".

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#363491

FromOdd Bodkin <bodkinodd@gmail.com>
Date2015-09-08 13:55 -0500
Message-ID<msnava$jdm$1@speranza.aioe.org>
In reply to#363359
On 9/7/2015 10:18 AM, Mike Fontenot wrote:
> Michelson-Morley (I think) said that no matter where the earth is in its
> orbit, it is always at rest wrt the ether (if there IS an ether).

No, that's not what it says. That's true for a NONLorentz ether.

-- 
Odd Bodkin --- maker of fine toys, tools, tables

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