My https://www.physicsforums.com/showthread.php?t=297616" was a pretext to discuss the well-known fact that it is nearly possible to derive the full Lorentz transformation without taking into account the constancy of the speed of light.

I went back to my physics hobby and read that in a few papers recently.

I find this interresting, altough this is probably very well known, if not obvious.

Simply assuming that a transformation must make a one-parameter (v) matrix group leads to the Lorentz-like group. (1)

This transformation depends then on an arbitrary parameter which is an unknown velocity (k).

This parameter could be determined from experience.

But it could also be identified as the propagation speed of a invariant massless vector field.

It is striking that the generic transformation groups must admit a limit velocity.

The Galilean solution appears as a very special case.

Why is it so that a limit velocity is the "most natural" solution?

Clearly it is all more about symmetries than about light.

Any thought, anygood reading about that?

Thanks.

(1) rejecting the rotation group

I went back to my physics hobby and read that in a few papers recently.

I find this interresting, altough this is probably very well known, if not obvious.

Simply assuming that a transformation must make a one-parameter (v) matrix group leads to the Lorentz-like group. (1)

This transformation depends then on an arbitrary parameter which is an unknown velocity (k).

This parameter could be determined from experience.

But it could also be identified as the propagation speed of a invariant massless vector field.

It is striking that the generic transformation groups must admit a limit velocity.

The Galilean solution appears as a very special case.

Why is it so that a limit velocity is the "most natural" solution?

Clearly it is all more about symmetries than about light.

Any thought, anygood reading about that?

Thanks.

(1) rejecting the rotation group

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