This week, Charlotte Birkmanis is chilling out, as she answers Alan's cool question: "I have heard it said many times that no two snowflakes are the same. Given the billions and billions of them that have fallen to Earth, this really does seem unlikely. Since nobody has looked at them all, would you agree with me that the only thing to be said with any certainty, is that no researcher has ever found two the same?" Like this podcast? Please help us by supporting the Naked Scientists