Witnessing a double-rainbow in nature may seem like a mystical experience, according to the famous video shot in Yosemite where the cameraman yells out in bliss: “What does this mean!”  Discovery de-mystifies what causes a double-rainbow to look so perfect, as though out of a fantasy movie or a commercial for Lucky Charms.


[youtube http://www.youtube.com/embed/zzrXA0-8sTg]

Image credit: puuikibeach/Flickr