Whether you are studying light in your current science curriculum or just want to have some hands-on fun, these 3 light science experiments are sure to be a hit. Better yet, they don’t require any special tools or equipment. Children (with the help of an adult) can conduct these experiments using materials you’re likely to have on hand!
A stroboscope is a device that cuts of flight at regular intervals of time. When you look through it at a rhythmically moving object, the motion seems to slow down or even to stop. A simple stroboscope is easily made by cutting eight narrow slots at evenly space intervals around the rim of a cardboard circle. Put a pin through the center and stick the pin into the eraser of a pencil so you can spin the disk in front of one eye.
Look through the moving rim at a rotating object (like a fan). Depending on the relative speeds of the stroboscope and object, the object will appear to be stationary or to move slowly in the direction of its actual spin or to move slowly in the opposite direction. This is because you see the object only at regularly space instants and do not see its movements in between.
Stroboscopic illusions are frequent in movies because the movie camera takes its series of pictures at even spaced intervals.