A series of slits moving rapidly past your eye allows you to see images in short bursts. Such rapid but fragmented views of moving objects can make the objects appear to jerk along, change speed, or even move backward.
Each Tuesday is EducationTuesday here at Adafruit! Be sure to check out our posts about educators and all things STEM. Adafruit supports our educators and loves to spread the good word about educational STEM innovations!