How do you measure rest length of a moving pole? To estimate, you would have to measure speed and position of the pole before it enters the barn. Then you would have to time the peak of the explosion to coincide with the pole entering the barn. Regardless, at high speed, the pole may not spend enough time in the barn to be damaged by the blast wave.

Suppose we tilt the light clock 90-deg such that the bouncing light within the clock travels in the same direction as the clock’s motion relative to the observer. Can we do a geometric-based time analysis in this case to show that time has slowed in the moving clock?