Futurama is both one of the funniest and one of the smartest TV shows ever made. In addition to just being consistently hilarious, quotable and often poignant, the show is packed to the brim with obscure references that only a handful of fans will probably pick up on the first time through. A lot of these references are math or science related, as many of the show's writers have pretty impressive academic backgrounds. The head writer and executive producer, David X. Cohen, graduated from Harvard with a B.A. in physics. He also has a degree in computer science from the University of California, Berkeley. Another one of the show's writers, Ken Keeler, graduated from Harvard with a PhD in applied mathematics. In fact, Keeler famously invented his own mathematical theorem for the Season 7 episode The Prisoner of Benda. The show is also a love letter to pop culture and other works of science fiction. There are plenty of obvious movie and TV show references throughout the series like to The Wizard of Oz, 2001: A Space Odyssey and Doctor Who, but there are also some references to some more obscure movies, TV shows and books that you may have missed the first time through. From some super nerdy science and math references to jokes based on lesser known books and TV shows, here are 15 great Futurama references you probably missed.