You will need:
- Sticky tape
1. Fold your paper in half and cut down the crease to make two identically sized pieces of paper.
2. Draw a sausage on one of the pieces of paper. Tip: do it in pencil first and go over in pen so it’s nice and bold!
3. Place the other piece of paper over the top of the first so that you can see the shape of the sausage underneath.
4. Draw some silly features onto the top piece of paper in pencil before colouring in.
5. Lay the piece of paper with the sausage on face down and use sticky tape to attach your pencil to it.
6. Use glue to securely attach the two pieces of paper together (with the pencil in the middle) back-to-back.
7. Rub the pencil backwards and forward between your fingers and watch to see your illusion appear!
How does the optical illusion work?
You’ve made a thaumatrope, a type of optical toy. As the pencil spins your brain isn’t able to see the two images separately so instead combines them into one. This is called persistence of vision.