Create a thaumatrope and investigate the phenomenon of persistence of vision.
You Will Need
Index Cards (4”x6”)
Transparent Tape (Optional)
Rubber Stamps etc
Fold the index card in half forming a double 4”x3” surface. Draw two pictures that, if combined, would form one picture. Draw one on each side. For example, you can draw a bird on one side and a cage on the other. NOTE: Make sure that you draw in the middle of each side of the card so your drawings will match up.
Place the drinking straw in the centre of the index card. Tape the straw in place. Fold the index card over to hide the straw. Tape and secure the three sides together with tape.
Hold the straw between the palms of both hands and twirl quickly. The best view is at about 18” from the face at eye level.
When you flip the thaumatrope back and forth you are able to see both pictures at once, thanks to the phenomenon of the persistence of vision. Persistence of vision is the eye’s ability to retain an image for roughly 1/30 of a second after the object is gone. The faster you flip it, the clearer the illusion appears. Cartoons and Movies work in the same way. Our brain interprets the frames as one, moving, composite picture.
You can have younger children use predetermined images that the children can colour and then glue onto the index card. You can even make scaled down copies of their favourite characters that they can use on one side and add something to the drawing on the other side of the index card.
Older children can create their own images and can even try using words or sentences, including their names. When doing this the letters must be carefully lined up so the words are readable.
Thanks to and adapted from tryscience.org (from a contribution by the St. Louis Science Center)