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Re: Relativistic rotating disc

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On 09-Aug-23 10:27 pm, Richard Hachel wrote:
> Le 09/08/2023 à 11:12, Sylvia Else a écrit :
>> Take a rotating disk whose centre is not moving. Consider a point on 
>> the disk and express the variation of its coordinates with time in 
>> terms of the coordinates of the centre of the disk.
>>
>> Now use the Lorentz transform to transform the coordinates of the 
>> point on the disk into some desired frame in motion relative to the 
>> centre of the disk.
>>
>> Job done.
>>
>> Sylvia.
> 
> My love Sylvia.
> I really like the very simple and very pure way in which you say things.
> It is true and important to note that the center of the rotating disc 
> does not move. This means that if the periphery of the disc is 
> constantly changing, and creates its own reference frame (like each 
> point on the disc), the center remains in the R reference frame of the lab.
> 
> You say that it is then necessary to apply the Lorentz transformations, 
> but the Lorentz transformations apply to the Galilean frames of 
> reference and not to the rotating frames of reference.
> 
> It's not that they are false if we do that, it's that the rotating 
> reference frame, as it accelerates, takes on absolute properties, and 
> deformations appear there.
> 
> But we'll talk about that again, because it's both very simple (once you 
> have all the transformation equations) and very complicated as long as 
> you don't have them all.
> 
> So no, the Lorentz transformations don't work for this specific case, 
> there are deformations while the disk starts accelerating, and it's not 
> the same disk as at the start in R. first convert the disk from R1 
> (resting in R) to R2 (spinning in R) and only later apply the TLs.
> 
> R.H.

You're overcomplicating things. A point is just a point. It has a set of 
coordinates, including time. It cannot be said to be moving, much less 
accelerating, because both of those involve more than one time, and a 
point only has one time coordinate.

Sylvia.

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Relativistic rotating disc Richard Hachel <r.hachel@frite.fr> - 2023-08-08 16:24 +0000
  Re: Relativistic rotating disc "mitchr...@gmail.com" <mitchrae3323@gmail.com> - 2023-08-08 10:59 -0700
  Re: Relativistic rotating disc JanPB <filmart@gmail.com> - 2023-08-08 13:45 -0700
    Re: Relativistic rotating disc Richard Hachel <r.hachel@frite.fr> - 2023-08-08 21:02 +0000
      Re: Relativistic rotating disc "mitchr...@gmail.com" <mitchrae3323@gmail.com> - 2023-08-08 17:09 -0700
      Re: Relativistic rotating disc Maciej Wozniak <maluwozniak@gmail.com> - 2023-08-08 21:38 -0700
      Re: Relativistic rotating disc JanPB <filmart@gmail.com> - 2023-08-08 22:28 -0700
        Re: Relativistic rotating disc Ross Finlayson <ross.a.finlayson@gmail.com> - 2023-08-08 22:39 -0700
          Re: Relativistic rotating disc Ross Finlayson <ross.a.finlayson@gmail.com> - 2023-08-09 19:13 -0700
  Re: Relativistic rotating disc Sylvia Else <sylvia@email.invalid> - 2023-08-09 19:12 +1000
    Re: Relativistic rotating disc Richard Hachel <r.hachel@frite.fr> - 2023-08-09 12:27 +0000
      Re: Relativistic rotating disc Sylvia Else <sylvia@email.invalid> - 2023-08-09 22:39 +1000
        Re: Relativistic rotating disc Richard Hachel <r.hachel@frite.fr> - 2023-08-09 12:52 +0000
      Re: Relativistic rotating disc Athel Cornish-Bowden <athel.cb@gmail.com> - 2023-08-09 19:14 +0200
        Re: Relativistic rotating disc Richard Hachel <r.hachel@frite.fr> - 2023-08-09 17:35 +0000

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