Did you know that rainbows are caused by an aspect of refraction called dispersion? Light waves of different frequencies (colors) bend different amounts. In most cases, this is not noticeable, but prisms make use of this to spread out the spectrum so we can see all of the colors. Violet light bends the most, with each color bending a little less up to red, which bends the least.

 

Recently, our Earth Explorers summer campers (pictured here) had the opportunity to experiment with prisms and examine light in this way in our gardens and around our science exhibits.

 

If you have a prism, there are all kinds of ways you can examine light, too. Try it out for yourself! Here are just a few things (of many!) you can explore:

• Do the colors appear in the same order every time?
• How much sunlight do you need to make a rainbow?
• Can you change the size of the rainbow?

What other ways can you use a prism to play with light?

[Photos by Stefanie Tanaka, summer intern]