Level: Elementary
Subject Tag(s): Physics, Optics
Effort Level: Low

Related Projects: Rainbows (Advanced)


White paper
Glass of Water
1. Fill a glass with water and place it on a white sheet of paper
2. Take a flashlight and shine it onto the glass of water at an angle such that the light hits the top surface of the water and shines through the glass, onto the white paper.
3. Play around with the angle and distance until you see a rainbow form on the paper


Sunlight contains all the colors of the rainbow, and so do our phone flashlights. Any light that looks white to us is actually made up of many colors. When we shine this white light into some thing other than air (ex. water), each color bends a different amount. So when we look at the like light afterwards, it has separated into different colors, making a pretty rainbow.


There are lots of other ways to make a rainbow-like effect. Try these out!
1. Prism Rainbows (show more...)
2. Mirror Rainbows (show more...)

Feeling gypped from this experiment? You sort of should 😛 There's so much more rainbow knowledge and fun to be had!  Learn more about natural rainbows, how they form, and the underlying physics/optics principles.