Physics
Thin Film Optics
Quick fact
A thin film needs to be only about a quarter-wavelength of light thick—approximately 100 to 200 nanometers—to produce strong visible interference colors.
Why this is interesting
Have you ever wondered why soap bubbles shimmer with rainbow colors, or why an oil slick on water shows swirling patterns? The answer lies in a surprising trick that light plays when it bounces off thin layers.