Re: [Phys-l] how to explain relativity

[Brian Whatcott <betwys1@sbcglobal.net>]

John Mallinckrodt wrote:
>  /snip/ [if you think] an unstressed object whose ends begin accelerating  
> simultaneously in its own original rest frame with identical proper  
> accelerations directed along the line joining them doesn't develop  
> internal tensile stress, then your analysis is mistaken.  As  
> explained in my previous message, references therein, and many more  
> available via Google, the only way for an object to avoid developing  
> internal stress is for it to undergo Born acceleration which requires  
> progressively larger proper accelerations for more rearward portions  
> of the object.
>
> John Mallinckrodt
Forget Born acceleration. Forget ropes. Any object with measurable 
extension along a line of acceleration develops internal stress along 
that line. Doh!

Brian W
(In the non-relativistic case, the stress is compressive towards the 
'aft' end where it is pushed, and extensive towards the fore end where 
it is pulled.)