This interactive demonstration compares the barn and pole perspectives of whether or not the pole fits inside the barn. Use the slider to set the relative speed between the pole and the barn. As you move the slider, what happens to the length of the pole in the barn’s perspective and the length of the barn in the pole’s perspective? Click the start buttons to see what happens from both perspectives. Don’t forget to reset and replay the animation at different speeds! You’ll observe that at “low” speeds (even at $0.5c$), both perspectives agree that the pole does not fit inside the barn. However, at high speeds, the pole fits inside the barn from the barn perspective, but it does not fit from the pole perspective. Is this a true contradiction? How can you make sense of both perspectives in a logically consistent way?