Science of snowflakes:
Caltech physicist Ken Libbrecht wrote the book on snowflakes. In fact, he is the author of several, including the Field Guide to Snwoflakes and The Secret Life of a Snowflake. We've posted before about Libbrecht's work and now he's the subject of a Smithsonian profile, The Art and Science of Growing Snowflakes in a Lab. Below, a fantastic animated gif of a snowflake's growth, accelerated.