This is fantastic. Distort measured people's reaction time by making them catch a falling ruler to see how quickly (or slowly) their brains can translate what they see into what they do. Putting the video to slow motion emphasises how silly our reaction times can be. Some of us are so slow we might not even catch the ruler!
Reaction time is a complicated thing! Most people have a delayed response of about 190 milliseconds. Using a falling ruler to test people's reaction times cleverly gives the test a form of measurement. And though you'll probably laugh and be surprised at how slow people can be, don't make too much fun of them because we're all probably just like that. [Distort]