Shubee says...
>My question is about the Lorentz transformation, which is derivable
>without Einstein's unnecessary requirement that all the clocks and
>rulers are standard.
>http://www.everythingimportant.org/r...ty/special.pdf

Einstein's goal was not to derive the Lorentz transformations,
but to understand the physics of bodies in motion. So it wasn't
enough to derive any old coordinate transformation, but to derive
a coordinate transformation such that the laws of physics have the
same form in any two coordinate systems related by that transformation.

The laws of physics that Einstein was ultimately interested in were:
(1) Newton's laws of motion, which held at least approximately, and
(2) Maxwell's equations for electromagnetism.

But for the thought experiments Einstein used to develop Special
Relativity, he used simpler stand-ins for these complicated laws.
Instead, he just used the following facts:

1. An object moving without the influence of any forces travels
at constant velocity.

2. A standard clock at rest between times t1 and t2 shows elapsed
time t2 - t1.

3. Light has the same speed c in all directions.

4. A standard meterstick at rest has length 1.

--
Daryl McCullough
Ithaca, NY