A wing and a prayer

So I discovered this experimental apparatus whilst on my lunch break. I didn't have much time to get a good shot and couldn't find a tripod, so apologies for that.

This experiment is designed for undergraduates to shine light onto fragments of iridescent butterfly wings and observe the properties of the scattered light. The colour of this wing comes not from a pigment, but from the nano-scale structure. Think about a soap bubble for a minute - why do you think it is rainbow-coloured? (Hint: the thickness of the soap skin is important).

The wing is a gorgeous, deep blue. Its colour changes depending on the angle you observe it from. It's wonderful!