Peacock feathers have often been considered a sign of bad luck. With their beautiful patterns and colours of blues, greens and yellows, how could anyone ever think a peacock feathers are bad luck? Of course the belief that peacock feathers are bad luck is nothing more than superstition, but what about the colours and patterns that you see on them? They are easily one of the most recognisable animal features on this planet. Ask just about anyone, from a small child up and they will be able to recognise what bird it came from. But did you know that the colours that you see on a peacock’s feathers are an optical illusion and the feathers are actually brown?
I bet you are now wondering how a brown feather can display such a varied mix of colours as an illusion. The peacocks feathers can display the different colours because they have structural coloration, and this is something that is really only visible under a microscope. The pigment of the feathers are brown, but its surface is microscopically scored with fine parallel lines which distort the visible light. These fine lines on the feathers mix with the brown pigmentation to display the beautiful colours that we see. But they can do something else, and you may have noticed it when looking at them.
Not only do the delicate and intrinsicate structures of their amazing feathers display the different colours that you see, they also make the feathers appear iridescent (appear to change colour as the angle of view changes). This is because of their structure. As they move the light strikes the lines in their feathers at different angles. This makes them appear to change colour in a similar way to a two-dimensional moving hologram that we see on cheap cards and toys.
So the next time you see a peacock remember that nature has created a wonderful optical illusion for you to enjoy. And remember, Peacock feathers are no more bad luck than a black cat or walking under a ladder. But keep an eye out for that evil Friday the 13th.