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

Groups > sci.physics.relativity > #585047

Re: Annotated version of SRT

Show all headers | View raw

Am 08.05.2022 um 21:33 schrieb JanPB:

>> Now we are still discussing the question, how Einstein's words should be
>> understood.
>>
>> We have here a simple situation: a beam is sent out by some source and
>> reflected back to its origin.
>>
>> The question is now: which variables belong to which quantities.
>>
>> This should not be a subject to debate in a good paper, but is in this case.
>
> It's not an object of debate among the intended audience of the paper.
> The text admits only one interpretation.

Sure, the intended audience would never ever dare to criticise a single 
word of Einstein.

But authors do not chose their audience.

>> I interpreted the setup this way:
>>
>> the emitter is placed in the zero spot of k at point xsi_0
>
> At the point  ksi_0 = 0.
>
>> the mirror is placed at some positive distance at the point xsi_mirror in k
>
> OK.
>
>> the hole thing moves in K to 'the right' with velocity v
>
> OK.
>
>> the moving setup is watched and measured from K with measures from K
>
> OK.
>
>> Now k is a copy of K, which 'slides' along the x-axis of K with velocity v.
>
> OK, except for the bizarre phrase "a copy of K".

A coordinate system is an imaginary construct, which humans have 
invented to describe spatial relations.

Now we 'materialize' this construct, hence K is a 'thing' (which is 
actually not).

This 'thing' gets duplicated and set into motion.

Then system k is a moving copy of K, which moves with velocity v along 
the x-axis of K.

This is a mutual relation, hence K is also a moving copy of k, which 
moves along the xsi-axis of k.

>> this allows to define the points xsi_0 and xsi_mirror from the
>> perspective of K with K-coordinates:
>>
>> x'= x(xsi_mirror)=xsi_mirror + v*t
>
> No, this is wrong. If you want to express the light source and mirror
> situation through the measurements made by  K,  then you can only
> use K-coordinates (no ksi).

This is in fact true. But the coordinates in K are not arbitrary, but 
defined by given relations.

The relation between K and k was given and also the relation between the 
points of emitter and mirror.

Now the zero spot of k is moving with xsi_0= x_0 + v*t, we can simply 
transform this equation by a trivial operation to x_0= xsi_0 - v*t, 
which we find in the text in a quite similar form.

Now xsi_0 was the position of the emitter and xsi_mirror was the 
position of the mirror.

For a linear transformation we would expect xsi_mirror= x_mirror - v*t.

Actually Einstein had not written so, but x' would fit to x_mirror and x 
to 'position of the emitter at xsi_0 = x_0 + v*t'.

Therefore x'= xsi_mirror + v*t.


> OTOH if you want to express  ksi  in terms of  K-coordinates, then you
> have to derive that relationship first (as Einstein does a bit later). You
> cannot just assume some random formula like "x'= x(xsi_mirror)=xsi_mirror + v*t"
> (you are confusing the actual physical positions with *coordinate values*.
> I understand what your intent is but you are expressing it in a mathematically
> nonsensical manner.

???


...

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> - 2022-05-01 09:59 +0200
  Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-05-01 12:16 +0000
    Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-02 08:03 +0200
      Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-01 23:31 -0700
        Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-05-02 08:56 +0000
          Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-02 02:30 -0700
      Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-02 00:18 -0700
        Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-04 06:53 +0200
          Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-04 01:02 -0700
            Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-05 09:02 +0200
              Crank Thomas Heger keeps on lying "Dono." <eggy20011951@gmail.com> - 2022-05-05 06:38 -0700
              Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-05 22:17 -0700
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-05 22:34 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-06 08:55 +0200
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-06 00:24 -0700
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-06 01:15 -0700
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-06 01:41 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-07 07:19 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-07 00:38 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-08 08:22 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-08 12:33 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-10 07:12 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-10 00:19 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-11 07:55 +0200
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-11 11:25 +0300
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-12 07:39 +0200
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-12 10:31 +0300
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-12 21:05 +0200
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-15 11:26 +0300
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-18 07:38 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-12 11:33 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-12 21:28 +0200
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-13 08:41 +0200
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-14 06:43 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-14 19:49 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-15 08:34 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-15 12:53 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-18 08:01 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-14 19:29 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-15 08:50 +0200
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-06 17:09 +0300
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-07 07:32 +0200
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-07 13:53 +0300
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-07 05:10 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-08 08:33 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-08 12:34 -0700
                Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-09 07:20 +0200
                Re: Annotated version of SRT JanPB <filmart@gmail.com> - 2022-05-09 02:24 -0700
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-09 03:04 -0700
                Re: Annotated version of SRT Mikko <mikko.levanto@iki.fi> - 2022-05-09 10:14 +0300
                Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-09 00:25 -0700
      Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-05-02 11:16 +0000
        Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-02 04:44 -0700
          Re: Annotated version of SRT Odd Bodkin <bodkinodd@gmail.com> - 2022-05-02 12:02 +0000
            Re: Annotated version of SRT Maciej Wozniak <maluwozniak@gmail.com> - 2022-05-02 05:11 -0700
        Re: Annotated version of SRT Thomas Heger <ttt_heg@web.de> - 2022-05-03 08:15 +0200

csiph-web