Cartoon Example
45 minutes
What do I need?
  • print-outs of the "Flipstick Cartoons", which you can click on in Step 1, or...
  • white paper that you can use for tracing and black marker or dark pencil
  • scissors
  • bright colored markers
  • clear plastic tape
  • file cards
  • pencil, straw, or chopstick
  • ruler

  What do I do?

1 Print-out the "Flipstick Cartoons". Click Here to go to the Cartoon page, then carefully cut along the dotted lines.


2 Choose one set of cartoons--picture A and picture B. You can color them if you want.


3 Tape each picture to a file card.



Tape each picture to a file card.

Tape each picture to a file card.



4 Turn the first file card over, so the picture is facedown. Put the pencil, straw, or chopstick in the center of the card, about 1 inch from the top, and tape it down.



Tape the pencil to the back of the card



Use plenty of tape. (If you're using a straw, you may want to flatten it a little before you tape it down.)



5 Now tape the two cards back to back. Lay the second card over the first, picture side up. Tape the top and sides of both cards together.

Tape the two cards back to back

Tape the bottom of each card to the pencil. You're going to twirl the pencil, so use plenty of tape--otherwise the cards might fly off.


6 Hold the pencil between the palms of your hands and twirl it. The picture changes! (You may need to play around with your twirling to find the best speed. Keep your thumbs flat against your fingers so they don't hit the card when you twirl.)

Wow! I didn't know that!

If a light is flashing on and off more than thirty times a second, you see it as a steady light--you don't notice the flickering. When you watch a movie, the screen is dark about half the time. But because the bright picture is flickering seventy-two times a second, you don't even notice the moments of darkeness between the pictures.


Why does your Flipstick work?

When you look at a picture, then quickly flip to another picture, your eye and brain remember the first picture for a fraction of a second, and blend it with the second picture. This visual ability, known as persistence of vision ,makes the pictures in movies appear to move.

When you watch a movie, the light from the projector is flickering 72 times a second. Your eye and brain blend the flickering frames of the movie to make a single moving picture.


Return to the Science Explorer

This and dozens of other cool activities are included in the Exploratorium's Science Explorer books, available for purchase from our online store .

About the Books

Published by Owl Books,
Henry Holt & Company, New York,
1996 & 1997

ISBN 0-B050-4536 & ISBN 0-8050-4537-6 ,
$12.95 each

© 1998 Exploratorium