If some deranged lunatic ever puts a gun to your head, demanding to know what alternate universes are and how they work, you should respond to this completely normal turn of events by showing them the episode of Community called, Remedial Chaos Theory. The entire episode revolves around the premise of a single die, and the six distinct timelines that it creates when rolled. All of this is explained explicitly by the TV and movie obsessed character, Abed.
The gang has gathered at a housewarming party for Troy and Abed. As they are gathered around a table, the doorbell rings. Someone has to answer the door. When Jeff Winger suggests rolling a six-sided die to see who should go, Abed warns the gang that they are about to create six different timelines, one for each possible result. When that advice is dismissed, the audience is treated to a glimpse at the new timelines as they unfold, each more hilariously disastrous than the last.
Remedial Chaos Theory does an excellent job of explaining the concept of multiple universe theory. It could also save your life in the event of the highly unlikely scenario with the lunatic.
What are your favourite alt-universe TV episodes? Let us know down in the comments.