Rainbows can multiply. Double, tertiary (triple) and quaternary (quadruple) rainbows all can occur. Double rainbows occur when light gets reflected twice inside water droplets. When this happens, the second rainbow appears above the main one and is fainter. Its colors are also reversed (red is on the inner section and violet on the outer arch) due to the second reflection [source: National Geographic].
A tertiary rainbow occurs when light is reflected a third time. But you have to be facing the sun to see one because the sun is its center. Tertiary rainbows are very difficult to notice partly because you're looking into the sun, and partly because they're quite faint and very broad. Even harder to see are quaternary rainbows, which form when light is reflected a fourth time. You also need to be facing the sun to spot these, and they're even fainter than tertiary rainbows [source: National Geographic].
And it doesn't stop there: Scientists have detected a 200th order rainbow (that's a rainbow with light reflected 200 times) in the lab!
So now it's time to confess. Were you stumped by any of these? If you weren't, I'd suggest investigating a career in meteorology.
Author's Note: 10 Myths About Rainbows
I definitely learned a thing or two (or three or four) from researching this article. Now I'm on a mission to spot a moonbow. Guess that means I need to go to the Caribbean ...
More Great Links
- Colours of the Rainbow. "Rainbow Legends." (Feb. 23, 2015) http://www.colours-of-the-rainbow.com/legends.html
- Edens, Harald. "Frequently asked questions about the rainbow." Weatherscapes. (Feb. 27, 2015) http://www.weatherscapes.com/techniques.php?cat=optics&page=rainbowfaq
- Howard, Jacqueline. "Two People Never See The Same Rainbow – And 6 More Amazing Facts About The Optical Phenomenon." The Huffington Post. Aug. 31, 2013. (Feb. 24, 2015) http://www.huffingtonpost.com/2013/08/31/facts-about-rainbows_n_3779801.html
- Lewin, Adrienne Mand. "7 colorful facts you didn't know about rainbows." Today. June 21, 2012. (Feb. 25, 2015) http://www.today.com/id/47891913/ns/today-weather/t/colorful-facts-you-didnt-know-about-rainbows/#.VO6NeyyGNCA
- Mahlen, Gena. "How a Rainbow is Formed." (Feb. 27, 2015) http://faculty.cord.edu/manning/physics215/studentpages/genamahlen.html
- Merali, Aliya. "Create Your Own Rainbow." Physics Central. (March 1, 2015) http://physicscentral.com/experiment/physicsathome/rainbow.cfm
- Mystical Myth. "Irish Pot of Gold." (Feb. 26, 2015) http://www.bellaterreno.com/art/irish/irish_potgold.aspx
- National Geographic. "Rainbow." (Feb. 23, 2015) http://education.nationalgeographic.com/education/encyclopedia/rainbow/?ar_a=1
- Plait, Phil. "Polarized rainbow, what does this mean???" Discover Magazine. Aug. 18, 2011. (March 1, 2015) http://blogs.discovermagazine.com/badastronomy/2011/08/18/polarized-rainbow-what-does-this-mean/#.VPMpVi6wjfY
- Polarization. Rainbow. "A Polarized Arch? Halos? Glories?" (March 1, 2015) https://www.polarization.com/rainbow/rainbow.html
- Rao, Joe. "Rainbows: How They Form & How to See Them. Live Science." March 15, 2011. (Feb. 27, 2015) http://www.livescience.com/30235-rainbows-formation-explainer.html
- Science Kids. "Rainbow Facts For Kids." (Feb. 23, 2015) http://www.sciencekids.co.nz/sciencefacts/weather/rainbows.html
- Your Irish. "The Magical Legend Of The Leprechaun." (Feb. 26, 2015) http://www.yourirish.com/folklore/the-leprechauns/
HowStuffWorks looks at why the U.S. stubbornly sticks with the Fahrenheit scale instead of switching to Celsius like the rest of the world.