Science Experiments: Ghost Fish

This experiment is all about Visual Perception. These are “after images”. They happen because the light-sensitive cones and rods at the back of your eye grow tired of the colour you stare at and then when you stare at white – other colours appear! So grab your little one and experience the ghost fish for yourself!

GHOST FISH

Visual perception – after images.

WHAT YOU NEED:

• 4 sheets of white card
• Coloured paper – red, blue and yellow
• Scissors
• Black marker
• Glue

WHAT TO DO:

• Draw the same simple fish shape on each sheet of coloured paper. Cut them out.
• Glue each coloured fish onto white card.
• Draw a small black eye on each fish.
• On the last white card, draw the outline of a bowl for your fish.
• Put the cards in a bright area.
• Stare at the eye of the red fish for 20-30 seconds, then quickly stare at the outline of the fishbowl.
• What do you see? Ghost fish appear! (You should see a pale green/blue fish!)
• Stare at the blue fish and a ghostly yellow fish appears!
• Stare at the yellow fish and a ghostly blue fish appears!