I hope you already know you shouldn’t believe every crazy-awesome thing you see on the internet; there’s a lot of fake stuff out there. But don’t worry, it’s possible to use physics and video analysis to see what’s real and what’s not.
In this case, some guys tweeted out this cool-looking soccer trick: One dude kicks a ball toward a wall that has an outline of a soccer goal on it, with two holes in the upper corners. At the same time, another guy tosses a ball from the side, and when the balls collide, they ricochet into the holes like billiard balls. It looks magical. Alas, it’s fake. If you look closely, you can see a cloud make a weird move, indicating a video edit (as spotted in an observant tweet).
But it’s more than just glitchy clouds. This soccer trick also breaks some physics rules. Really, this is the fun part–using some fundamental ideas to show that the video is fake.
I’m going to start with the ball that’s tossed from the the side. I can easily measure the motion of this one because it’s moving across the camera’s field of vision. Using the Tracker video analysis tool, I can mark the horizontal and vertical location of the ball in each frame of the video. Also, by looking at the frame rate, I can put a time stamp on those coordinates.
With that, I get the following plot of horizontal position vs. time for the tossed ball: