I always wanted to know why the Advanced Television Committee went with such an odd aspect ratio for the new digital television standard. Turns out one guy, Dr. Kerns Powers, discovered that this ratio would cover all of the existing formats of film, from super wide screen 2.35 down to TV and old film size of 1.33.
Check out these entertaining and informational instructional videos from Craig Syverson, the videogrunt. Highly recommended.