Butterfly Wing

Challenge

How do butterflies get iridescent colored wings?

Supplies

• • Butterfly

  • Images of butterfly wing at nanoscale

What to do

• 1. Look at the blue butterfly wing

  2. Ask visitors where else in nature they have seen that color

  3. Compare the blue top of the wing to the brown underside

  4. Examine the nanoscale structure of the wings

Inquiry Questions

• • What causes the blue color?

  • How does the surface texture affect what we see?

  • How does this relate to the colors seen in bubbles?

What’s happening?

The blue color come from the nanoscale structures on the surface of the wing. These fins are only 400 nanometers long which is about the same as the wavelength of violet light. These structures cause interference patterns in the light that bounces off them and we see it as blue.

The interference of reflected light is also what gives rise to the rainbow of colors we see in bubbles. There the interference is between the front and back of the bubbles.