The text accompanying E. Blaise Saccocio’s double rainbow picture should have pointed out the existence of supernumerary rainbows clearly visible inside the primary rainbow. Although the primary and secondary rainbows are explainable in terms of geometric optics, the supernumerary rainbows are not, because they are a manifestation of light interference within a raindrop. In fact, it was an observation of supernumerary rainbows that prompted Thomas Young to perform the famous double-slit experiment in 1801, which confirmed the wave nature of light and led to his explanation of these rainbows in 1803. For more information and pictures, see references 1 and 2.
REFERENCES
1.
Raymond L.
Lee
Jr , Alistair B.
Fraser
, The Rainbow Bridge: Rainbows in Art, Myth, and Science
, Pennsylvania State U. Press
, University Park, PA
(2001
); see especially chap. 8, available at http://www.usna.edu/Users/oceano/raylee/RainbowBridge/Chapter_8.html.2.
M.
Sawicki
, P.
Sawicki
, Phys. Teach.
38
, 19
(2000
). Available at http://www.jal.cc.il.us/~mikolajsawicki/rainbows.htm. © 2004 American Institute of Physics.
2004
American Institute of Physics
