1. The problem statement, all variables and given/known data The Pole and Barn Paradox Suppose a very fast runner (v=0.600c) holding a long horizontal pole runs through a barn that is open at both ends. The lenght of the pole (in its rest frame) is 6.00m, and the lenght of the barn (in its rest frame) is 5.00m. In the barn's reference frame, the pole will undergo length contraction and the entire pole can fit inside the barn at the same time. But in the runner's reference frame, the barn will undergo length contraction, and the entire pole can never be entirely within the barn at any time! Explain the resolution of this paradox. (A spacetime diagram may be useful.) 2. Relevant equations u = speed of reference frame S' v = speed of particle Spacetime diagram slopes: Slpoe of worldline of particle: c/v S' reference frame axis slopes: Slope of x'-axis: u/c Slope of ct'-axis: c/u 3. The attempt at a solution Let S be the reference frame of that barn, where the barn is at rest. Let S' be the reference frame of the runner, where the pole is at rest. S' is moving inertially in relation to S at a speed of 0.600c in the positive x-direction. Let event A be the time and position in S when the forward facing end of the pole reaches x=5. Due to length contraction, the pole is 4.8 meters long in S, and the barn is 4 meters long in S'. Since the pole is at rest in S', the worldline of the front end of the pole will be paralell to the ct'-axis and intersect the x-axis at x=5. It will also intersect the x'-axis at x'=6.25. Event A is NOT simultaneous in S and S'. By the time the runner measures that the front end of the pole has passed reached the end of the barn, an observer at rest inside the barn will measure a fraction of the pole have already passed through the barn. In short, the pole passes through the barn later in S' then in S. That is as far as i have gotten with this problem. is it a suffiecient explanation? If not, am I on the right track? Thanks for any help.