🚀 go-pugleaf

PD <TheDraperFamily@gmail.com> wrote in message
  08d88bd5-1988-4105-babe-301d55875edd@m19g2000yqk.googlegroups.com
> On Jun 12, 1:51 am, Pentcho Valev <pva...@yahoo.com> wrote:
>> http://math.ucr.edu/home/baez/physics/
>> 
>> http://math.ucr.edu/home/baez/physics/Relativity/SR/barn_pole.html
>> "These are the props. You own a barn, 40m long, with automatic doors
>> at either end, that can be opened and closed simultaneously by a
>> switch. You also have a pole, 80m long, which of course won't fit in
>> the barn. Now someone takes the pole and tries to run (at nearly the
>> speed of light) through the barn with the pole horizontal. Special
>> Relativity (SR) says that a moving object is contracted in the
>> direction of motion: this is called the Lorentz Contraction. So, if
>> the pole is set in motion lengthwise, then it will contract in the
>> reference frame of a stationary observer.....So, as the pole passes
>> through the barn, there is an instant when it is completely within the
>> barn. At that instant, you close both doors simultaneously, with your
>> switch. Of course, you open them again pretty quickly, but at least
>> momentarily you had the contracted pole shut up in your barn. The
>> runner emerges from the far door unscathed.....If the doors are kept
>> shut the rod will obviously smash into the barn door at one end. If
>> the door withstands this the leading end of the rod will come to rest
>> in the frame of reference of the stationary observer. There can be no
>> such thing as a rigid rod in relativity so the trailing end will not
>> stop immediately and the rod will be compressed beyond the amount it
>> was Lorentz contracted. If it does not explode under the strain and
>> it is sufficiently elastic it will come to rest and start to spring
>> back to its natural shape but since it is too big for the barn the
>> other end is now going to crash into the back door and the rod will be
>> trapped in a compressed state inside the barn."
>> 
>> The premise on which this conclusion is based is Einstein's 1905 light
>> postulate so if rationality in science had not been destroyed,
>> Einsteinians would have presented the above deduction as REDUCTIO AD
>> ABSURDUM and, accordingly, would have rejected the light postulate as
>> false.
> 
> Why? There is no contradiction here. There are no measurably
> distinguishable outcomes here where the claim is "A will be observed"
> and "A will NOT be observed". Reductio ad absurdum requires there to
> be internal contradiction.
> 
> A surprise, counter to your intuitive expectations, is not a
> contradiction. It is just a surprise, much as would be finding a
> spider monkey in an elevator. But a spider monkey in an elevator is
> not a contradiction, either.
> 
> Moreover, an equivalent experimental result has been confirmed. There
> is nothing in nature that really occurs that can ever be called a
> contradiction.

A human being as dumb as a spider comes pretty close though.

Dirk Vdm