John Green is a busy guy. Besides being the bestselling author of The Fault in Our Stars, John and his brother Hank Green, together known as the Vlogbrothers, also produce a variety of YouTube channels with millions of subscribers. The Crash Course channel features clever, fast-paced, fun and very educational videos on all sorts of topics. John covers humanities with courses on World History, US History, and English Literature. Hank’s courses in the sciences cover Biology, Ecology, Chemistry, Physics, and Psychology. Most of videos are about 10-12 minutes long and feature fun animation and an engaging lecture. If you need to get a quick overview of Mary Shelley’s Frankenstein or to find out about Heredity, try a Crash Course with a Green brother. And, as the Green brothers say, DFTBA!