If you are going on you are ready for the Pole In Barn paradox


You have a 20m pole and a 10m barn and we are going to play games and move it up to 0.9c and pass it thru the barn doors at each end of the barn ... we have 3 different observers

a) Which will be you classical lug heads that says the 20m pole wont fit in the 10m barn. It's obvious you claim as you stood there and measured both with a tape measure. Everyone knows a 20m pole wont fit in a 10m barn ... dah how stupid can you scientists be.

b) This group will sit on the roof of the barn see a the pole as 8.7m long approaching at 0.9c and as it enters the barn they close the doors each end simultaneously fully enclosing the pole in the barn. Quickly open the doors and it exits unscathed. To them you miss measured the pole and it is only 8.7m long and it fits completely in the stationary 10m barn.

c) This group are sitting on the pole approaching at 0.9c and they are on a 10m pole approaching the barn. To them the barn is only 4.37m long and both of you miss measured the length of the barn. They passes thru unscathed because the doors open and close at completely different times.

ALL 3 OBSERVATIONS ARE PERFECTLY CORRECT. The problem is it plays with our view with classical physics that there is only one answer which is (a).

The 3 Observers will never agree on anything and yet every observer is correct smile

You are going to be with group (a) and tell us the other two observers are wrong ... admit it .. you measured it and you know your mathematics.
GOD Dave lives we have our racist frame he will select the "Pure right one" and doubt the other observers laugh

The reality is you can make a 20m pole fit in a 10m barn if you move it at 0.9c because your measurement of length is loaded to a reference frame ... you chose the non moving one to measure. There is no global universal measurement and correctness of length. Your 20m pole is only 20m long in your reference frame.

That is why scientists get upset with mixing measurements from one reference frame to another. A 20m pole wont fit in a 10m barn if both measurements were done in the same reference frame. The mistake the (a) group zealots make is they assume the measurement in there frame is absolute in all reference frames and the pole can never fit in the barn. Move the pole at 0.9c it's actual length is truely 8.7m long if measured in the stationary frame and yes it fits in the barn.

The same problem exists with time it really does change with movement.

Welcome to relativity ... Dave runs screaming from the building no my classical physics says no.

Edited by Orac (08/29/15 11:40 AM)
I believe in "Evil, Bad, Ungodly fantasy science and maths", so I am undoubtedly wrong to you.