On Jul 24, 1:53 pm, "Pmb" <some...@someplace.com> wrote:
> "maxwell" <s...@shaw.ca> wrote in message
> 
> news:9f886067-0f46-4f9f-9210-d6b16b13c0f5@z6g2000pre.googlegroups.com...
> 
>> Reading Einstein's 1905 SRT paper shows that he makes extensive use of
>> the concept of a 'rigid body' (or rod). This was a conceptual
>> innovation of Euler and has no reality in a world of discrete atoms.
>> How can Einstein's derivation of the LT etc in this paper have any
>> PHYSICAL relevance when his conceptual tools are purely mathematical?
> 
> There is no problem with Einstein's use of a rigid body. In fact the concept
> of a rigid body is not always wrong. A rigid body is a body for which the
> distance between two points on the body remains constant. That will be true
> when no forces are applied to the body.
> 
> Pete

Wake up, guys. The point about using a 'rigid body' (as Einstein knew)
is that both ends move SIMULTANEOUSLY - a contradiction with his idea
that nothing substantial can move faster than light-speed: hence the
paradoxes.