If the ball was moving at 100 mph as it passed him, he would have to swing at at least 101 mph to “catch up” to it. But a blade moving that slowly would not be able to slice through the ball.
“If the ball was moving at 100 mph as it passed him, he would have to swing at at least 101 mph to “catch up” to it. But a blade moving that slowly would not be able to slice through the ball.”
Huh? No way man. He only has to move fast enough to get the sword in the way of the ball. A pedestrian does not have to run 56 miles per hour to get hit by a car. They only have to step off the sidewalk. He would only have to go faster if he was swinging from behind the ball... sort of like the pitcher standing behind a batter and the batter swinging to ‘catch up’ to the ball. But that is not how this worked. Instead it was more like a bunt. He drew his sword and swung it in the way of the ball and the ball cut itself by flying though the blade. He started is draw when the ball shot out. He moved his sword only about 45 inches and the ball flew several yards. Rough estimate indicates the blade was moving at least a couple times slower than the ball.
But what do I know, my physics education only extends to a degree in mechanical engineering.