This is a story about a horse—a horse whose fate was inextricably tied to the invention of film. It all started in 1872, when eventual Stanford University founder Leland Stanford made a bet with some colleagues. The bet in question concerned whether, at any point during a gallop, all four of a horse's hooves were off the ground at the same time. Stanford contacted an English photographer named Eadweard Muybridge to set things straight. With a horse running along a row of cameras all set to tripwires, Muybridge settled the bet in Stanford's favor. But the bet ultimately paled in comparison to Muybridge's achievement: for his tripwire-camera exploits, Muybridge is now considered one of the fathers of the motion picture.