Explanation
Mnemonic for the order & colors of the rainbow (Red, Orange, Yellow, Green, Blue, Indigo, Violet). The first letter of each word gives you the first letter of what it stands for.
This order isn't random - it's the order light naturally splits into whenever it bends, whether that's raindrops making a rainbow or a glass prism on a windowsill, so it comes in handy in both art and science class.
A rainbow forms because sunlight bends as it enters a raindrop, bounces off the inside back wall of the drop, and bends again on its way out. Sunlight looks white, but it's actually made up of all the rainbow colors at once - all that bending fans the colors apart, and that fanned-out light is exactly the colored arc you see.
Sometimes you'll spot a second rainbow above the first one, fainter and wider, with the colors reversed:
- VIBGYOR
Note: whether indigo really deserves its own separate band in the rainbow has long been debated among physicists. Newton added indigo to land on seven colors (to match the seven notes of a musical scale), but the human eye struggles to tell indigo apart from blue and violet in practice. For a test, it's safest to include it whenever you're asked for "the colors of the rainbow," but don't be surprised if you see it left out elsewhere.
Light is just a part of the spectrum of EM-waves: see our mnemonic on all EM-waves
Variations
- Read Out Your Good Book In Verse
- Richard Of York Gave Battle In Vain
- Richard Of York Got Buggered In Venice