This optical illusion lets you turn two pictures into one.
What you need:
- white cardboard
- pencils and colouring pens
- Cut out two shapes from a sheet of white cardboard.
- Draw whatever you want, but we tried some fish on one piece and the tank on the other.
- Glue or sellotape a pencil in between the two pictures.
- Hold the pencil between your palms and rub your hands to make the picture spin around.
The Science bit
The fish should look like they are inside the tank.
This is the same concept used for making cartoons, still pictures are moved very quickly to create an illusion of movement.