By NewEnglandBob (not verified) on 08 Sep 2010 #permalink Thanks for a lesson relatively easy to understand. By ThirtyFiveUp (not verified) on 08 Sep 2010 #permalink The quote is from Leonardo Da Vinci. Nice pics though, Thanks for sharing them. By Tom (not verified) on 08 Sep 2010 #permalink Excellent post! I had seen photo's like that before, but never realised what was causing the rainbow. @Tom, actually I think Ethan got it right. The quote (one of my favourite aviation quotes) is commonly attributed to da Vinci. However, no-one can actually point to a verifiable da Vinci source for it - see the comments on this website, and the author's attempts to verify the source (near the bottom) http://www.skygod.com/quotes/