Coke, Light, Caustics, and a Pokemon Face?
When a nearly empty plastic bottle of Coca-Cola is illuminated from above, the freeform lens that's created focuses light, forming fanciful caustics. A four-light lamp in the ceiling projected the pattern projected onto a white sheet of paper, and the pattern was shot using an iPhone. Do you see the face?
—José A. Díaz, Universidad de Granada, Spain