Linearity of the Loentz transformations

  • Context: Graduate 
  • Thread starter Thread starter bernhard.rothenstein
  • Start date Start date
  • Tags Tags
    Linearity Transformations
Click For Summary

Discussion Overview

The discussion revolves around the justification for the linearity of the Lorentz transformations, exploring theoretical underpinnings and implications in the context of special relativity. Participants examine various aspects of the transformations, including their derivation and the physical significance of linearity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that the Lorentz transformations should be linear because each event in one inertial frame corresponds to a single event in another frame.
  • Homogeneity is mentioned as a key principle, suggesting that distance and time intervals must be independent of the choice of origin, as noted in Einstein's 1905 paper.
  • There is a suggestion that linearity is necessary to ensure that straight worldlines in one frame transform into straight worldlines in all other frames.
  • One participant argues that the linearity of the Lorentz transformations arises from Einstein's derivation, which involves a Taylor expansion that leads to linear terms, with higher-order terms proving to be zero.
  • Another participant humorously suggests that the transformations are linear because they are the simplest option available.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the justification for linearity, with no consensus reached on a singular explanation or approach.

Contextual Notes

Some arguments depend on interpretations of Einstein's original work and the implications of homogeneity, while others raise questions about the nature of transformations beyond linearity.

bernhard.rothenstein
Messages
988
Reaction score
1
Please give a plausibile justification for the linearity of the Lorentz transformations. Would you accept: The Lorentz transformations should be linear because to one event in I should correspond a single event in I'
 
Physics news on Phys.org
Homgoneity -distance and time intervals must be independent of the choice of origin. This is mentioned but not explained in detail in Einstine's 1905 paper, I believe.
 
linearity

pervect said:
Homgoneity -distance and time intervals must be independent of the choice of origin. This is mentioned but not explained in detail in Einstine's 1905 paper, I believe.

Thanks. Could that be better: The transformations should be linear because straight worldlines (i.e. constant velocity worldlines) in one frame must transform into stright worldlines in all other?
 
bernhard.rothenstein said:
pervect said:
Homgoneity -distance and time intervals must be independent of the choice of origin. This is mentioned but not explained in detail in Einstine's 1905 paper, I believe.

Thanks. Could that be better: The transformations should be linear because straight worldlines (i.e. constant velocity worldlines) in one frame must transform into stright worldlines in all other?

That's better [since your previous justification allows (say) conformal transformations, which need not preserve lines]. You may recall this earlier thread: https://www.physicsforums.com/showthread.php?p=1079973
 
bernhard.rothenstein said:
Please give a plausibile justification for the linearity of the Lorentz transformations. Would you accept: The Lorentz transformations should be linear because to one event in I should correspond a single event in I'
In physical terms, I would say LT ius linear so that constant velocity in one frame will not lead to acceleration in another frame. That is equivalent to straight world lines.
 
bernhard.rothenstein said:
Please give a plausibile justification for the linearity of the Lorentz transformations. Would you accept: The Lorentz transformations should be linear because to one event in I should correspond a single event in I'

The linearity of the Lorentz transforms comes from the way Einstein derived them in his 1905 paper. He starts with the clock synchronisation condition, uses a Taylor expansion in order to produce a PDE. Solving the PDE produces the LT. By stopping the Taylor expansion to the rank one terms, Einstein forces the LT to be linear.
What if Einstein continued the Taylor expansion to higher terms? It can be proven that the resulting LT transforms are STILL linear! i.e. the coefficients of the higher order terms intervening in the LT's derived this way are zero.
 
Careful, Shubee is linking to (apparently) his own website, everythingimportant.org which generally runs counter to mainstream physics/math. Unfortunately, this is only one of literally hundreds of such websites which pretend to describe relativistic physics... sigh...
 
Why linear? Because they are the easiest.
LOL!

Chris:
Please define "mainstream".
 
Last edited:
linearity

quantum123 said:
Why linear? Because they are the easiest.
LOL!

which are the harder?
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
3
Views
2K
  • · Replies 101 ·
4
Replies
101
Views
7K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 22 ·
Replies
22
Views
2K