The Badge Archive

Newton Disk Spinner

Activity Description: Scouts build and test a Newton Disk spinner to explore how combining colors creates white light.

Info Needed: Visible light is made up of many colors, even though it looks white to our eyes. When light bends, reflects, or spreads out, we can see those colors as a rainbow or pattern. Scientists use these color patterns to study stars and space, learning what stars are made of, how they move, and how much energy they give off

Items Needed:

  • White paper (one sheet per scout)
  • CDs or DVDs (used as templates)
  • Pieces of cardboard larger than the CD or DVD (one per scout)
  • 36 inches of string (one per scout)
  • Colored pencils: red, orange, yellow, green, blue, purple
  • Pencils
  • Scissors
  • Glue sticks
  • Rulers
  • Star Notebook

Instructions (Estimated Total Time: 35–45 min):

  1. Record predictions in the notebook (5–7 min)
    • Scouts answer: What color is sunlight? How do we know? Is it made of more than one color?
    • Organize answers for later comparison.
  2. Create the colored disk (10–12 min)
    • Trace the inner and outer circles of a CD/DVD onto white paper.
    • Divide the large circle into six equal parts and color each section with a different color.
    • Cut out the large circle, leaving the center circle intact.
  3. Build the spinner base (8–10 min)
    • Trace the same circles onto cardboard and cut out only the outer circle.
    • Glue the colored paper circle onto the cardboard, colored side facing out.
    • Punch two holes on opposite sides of the inner circle.
  4. Add the string and assemble (5–6 min)
    • Feed each end of the string through the holes to form a loop on one side and two loose ends on the other.
    • Tie the loose ends together in a knot.
  5. Spin and experiment (5–7 min)
    • Scouts spin the disk by pulling and loosening the string.
    • Try different speeds and directions.
    • Observe how the colors blend and what changes occur.
  6. Record and compare results (5–7 min)
    • Scouts write down what they saw and compare it to their predictions.
    • Discuss how combining colors can create white light.
  7. Share discoveries with the group (3–5 min)
    • Scouts take turns sharing one observation or surprise.
    • Reflect on how scientists use light to study stars and space.

Step by Step Tutorials

  • Newton Disc Spinner – Instructables – A hands-on guide with photos and optional 3D-printing instructions. It explains how spinning colored segments blends light into white and introduces the concept of temporal optical mixing.
  • Newton Disc – My World Their Way – A kid-friendly tutorial with clear visuals and printable templates. It walks through each step using household materials and explains how the disc demonstrates the blending of rainbow colors into white light.
  • Newton’s Disk – Little Bins for Little Hands – A printable PDF with step-by-step instructions and diagrams. It includes a color wheel template and explains the science behind color addition and how our eyes perceive white light.
Tia Kennard