In Praise of Buttercups

We all have fond memories of playing the buttercup game. You simply hold a buttercup flower underneath your chin, and if your neck lights up yellow then it's conclusive, empirical proof that you like butter.

But physicists at the University of Cambridge have discovered the real reason that these flowers give off that golden glow. Disappointingly, it's more about the unique interplay of the petals' epidermal layers, and less about your fondness for margarine.