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Build a Thaumatrope!

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Physics Volunteer Activities
Main Image
Physics Volunteer Activities
Activity Language
Time Needed for Activity

Students will design an illusion in order to understand how motion is perceived.

What You Need

For each child:

  • White Cardstock (Alternative: white paper)
  • Object with a circle base about 2 inches in diameter (ex: cup)
  • Scissors
  • Pencil crayons, markers, etc.
  • Tape
  • Pencil, straw, dowel or skewer

PowerPoint:

Safety Notes

Ensure you are familiar with Let's Talk Science's precautions with respect to safe delivery of virtual outreach to youth. These precautions can be found in the manual for this activity. 

What To Do

  1. Use the object with the circular base to trace out two circles on the cardstock or paper. Cut the circles out.
  2. Choose a simple image to create an illusion out of. (Examples: clouds and rain, butterfly and flower, bowl and goldfish)
  3. Draw one part of the image on the first circle (ex: goldfish)
  4. Draw the second part of the image on the second circle (ex. fishbowl)
  5. Tape the circles to either side of the pencil, straw, dowel, or skewer. Ensure the pictures are facing outwards.
  6. Wrap your fingers around the dowel and spin it. What do you see?

When you spun the circles at the top speed, circle 1 and 2 merged together and you saw goldfish in the fishbowl, even though they were on separate circles. Your brain doesn’t process the two sides as two different images and creates one whole picture! Our brain does this to help us understand movement better. For example, when you watch a person walk across a room, you don’t visualize every single movement they perform. Instead, you see it as one continuous motion. 
 

What happens with you keep your eyes open vs. blink?

When you started blinking and spinning the thaumatrope, your brain could not connect the separate images as it did when your eyes were open so you would have observed more disconnected movements. 
 

What's Happening?

When you spun the circles at the top speed, circle 1 and 2 merged together and you saw goldfish in the fishbowl, even though they were on separate circles. Your brain doesn’t process the two sides as two different images and creates one whole picture! Our brain does this to help us understand movement better. For example, when you watch a person walk across a room, you don’t visualize every single movement they perform. Instead, you see it as one continuous motion. 
 

Investigate Further

What happens with you keep your eyes open vs. blink?

When you started blinking and spinning the thaumatrope, your brain could not connect the separate images as it did when your eyes were open so you would have observed more disconnected movements.