Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.physics.relativity > #583886

Re: Annotated version of SRT

Show all headers | View raw

Am 24.04.2022 um 10:23 schrieb JanPB:

>>>> Before you crank out insults, you should at least ask google for the
>>>> meaning of 'Gallileo transformation'.
>>>>
>>>> The very first result would be this:
>>>>
>>>> https://en.wikipedia.org/wiki/Galilean_transformation
>>>>
>>>> Quote:
>>>>
>>>> " x' = x- v*t "
>>>>
>>> Just because the Galilean transformation is x' = x-vt doesn't mean every
>>> instance of "x'=x-vt" is the Galilean Transform.
>>> This is an example of the logical fallacy: If A then B implies If B then
>>> A. (If NOT B then NOT A is true, however)
>> You are absolute right, that this was not meant as Galilean
>> transformation, even if the equation of that transform was used.
>>
>> In fact Einstein made an error:
>>
>> he used 'x' in his equation "x' = x- v*t"
>
> No, this is correct.
>
>> Instead of that, actually:
>> x' = xsi - v*t
>> was meant with xsi=0.
>
> No.
>
>> The setting was: a light beam was sent from the zero spot of k to the
>> point x'. There was a mirror placed, which reflected the beam back to
>> the source.
>>
>> Now the zero spot of k has the xsi-coordinate xsi=0.
>>
>> This point moves along the X-axis of K with velocity v. Now we have:
>> x' = xsi - v*t (correcting Einstein's obvious error from above).
>
> No, this is wrong.  x'  is defined as  x - vt.  It's just a definition of a new
> variable called  x',  introduced for convenience.  One could call this
> "Galilean transformation" only in the sense that the coordinates  (x, y, z, t)
> are being changed to  (x', y, z, t) the "Galilean" way but the physical
> context is wrong: the term "such-and-such transform" usually refers
> to two observers whose space and time coordinates are being related
> by the transformation. But here the context is that we have only one
> observer (K) who for convenience relabels one of the axes.

What did you mean by:

"It's just a definition of a new variable called  x',  introduced for 
convenience."

To me this sounds like nonsense, because what kind of convenience is 
required and for which purpose? Where was that purpose introduced?




This is the sentence of §3, page 6, which contains that equation.

"If we place x' = x −vt, it is clear that a point at rest in the system 
k must have a system of values x', y, z, independent of time."

Now the question arises, what Einstein meant with his statement.

 From the context I had assumed, he provided the mathematical 
description to his 'thought experiment', where a beam of light is 
emitted from the center of k towards a mirror placed somewhere on the 
x-axis of K at a point with the name x'.

But if you disagree about this interpretation, I'm lost, because after 
weeks of dealing with that particular part,  I have not found any other 
possible interpretation.

Therefore, I have to ask you, if you could be so kind and say, what 
Einstein actually meant with the quoted text.



> Note that it's important that this relabelling be linear since the final
> transform (x, y, z, t) -> (ksi, eta, zeta, tau) is required to be linear.
>
>> Therefore the point x' must be the zero spot of K, which has the
>> x-coordinate x'=0.
>
> There is no "spot of K" corresponding to  x'.  What  x'  is is simply
> a mathematical formula involving  K's  x  and  t  coordinates designed
> to remain a fixed number when  x  and  t  refer to a point moving at
> speed  v  wrt  K.
>
>> This is all nice and possible, but would invalidate most of the
>> subsequent equations for a number of reasons.
>
> Nothing is invalidated, everything is corret there.
>
>> For instance del x' in the denominator would not make much sense, if x'=0.
>
> I'm compelled to ask at this point: do you know calculus?
>

To me it is totally idiotic to put zero into a denominator in a 
differential equation.

But if x' denotes a fixed position, the value of del x'/del tau is zero. 
Now the inverse would be infinite.

That can hardly be what Einstein had in mind.

So please be so kind and explain to me, what else he had in  mind.


TH

Back to sci.physics.relativity | Previous | Next — Previous in thread | Next in thread | Find similar

Thread

Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-21 08:53 +0200
  Re: Annotated version of SRT Reinhardt Behm <rbehm@hushmail.com> - 2022-04-21 13:13 +0000
    Re: Annotated version of SRT Paul Alsing <pnalsing@gmail.com> - 2022-04-21 07:32 -0700
    Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-21 13:51 -0700
    Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-21 23:24 +0200
      Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-04-21 21:10 -0700
      Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-22 08:38 +0200
        Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-22 11:00 +0200
          Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-23 08:07 +0200
        Re: Annotated version of SRT RichD <r_delaney2001@yahoo.com> - 2022-04-23 14:59 -0700
          Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-24 07:36 +0200
          Re: Annotated version of SRT nospam@de-ster.demon.nl (J. J. Lodder) - 2022-04-24 10:41 +0200
            Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-04-24 01:59 -0700
            Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-26 09:02 +0200
  Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-21 13:48 -0700
    Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-22 09:00 +0200
      Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-22 01:41 -0700
        Re: Annotated version of SRT Dong Vassilikos <saox@cowrpsho.rb> - 2022-04-24 12:23 +0000
      Re: Annotated version of SRT Python <python@example.invalid> - 2022-04-22 15:39 +0200
        Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-04-22 07:11 -0700
        Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-23 07:55 +0200
          Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-23 03:34 -0400
            Re: Annotated version of SRT Python <python@example.invalid> - 2022-04-23 11:52 +0200
              Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-04-23 05:49 -0700
              Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-24 08:07 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-24 01:52 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-25 09:52 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-25 12:22 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-26 07:02 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-25 23:52 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-26 22:24 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-26 17:35 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-27 07:59 +0200
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-28 07:14 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-28 01:45 -0700
                Re: Annotated version of SRT Rady Konoe <akde@oakoradn.en> - 2022-04-28 09:03 +0000
            Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-24 07:49 +0200
              Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-24 01:23 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-24 11:08 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-24 05:14 -0700
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-04-24 12:46 -0700
                Re: Annotated version of SRT Dong Vassilikos <saox@cowrpsho.rb> - 2022-04-24 21:09 +0000
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-25 10:23 +0200
                Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-24 12:56 -0400
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-25 10:09 +0200
                Re: Annotated version of SRT Michael Moroney <moroney@world.std.spaamtrap.com> - 2022-04-25 11:51 -0400
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-04-26 07:22 +0200
          Re: Annotated version of SRT Cody Sakellariou <yall@ckcldcdd.ar> - 2022-04-23 07:59 +0000
          Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-04-23 12:56 +0000
    Re: Annotated version of SRT Dong Vassilikos <saox@cowrpsho.rb> - 2022-04-24 21:21 +0000

csiph-web