It was always agreed that a galloping horse kept at least one hoof on the ground. But in 1872, Californian governor and railroad tycoon Leland Stanford, who was a race horse owner, took a bet for $25,000 (the equivalent of $500,000 today) that all four hooves sometimes leave the ground. He hired English photographer Eadweard Muybridge to capture the movement of horses to prove his point.
But Standford to wait 5 years for the results. Muybridge, an eccentric persona, was hiding in South America after being blamed for the death of his wife’s lover. On his return to the US in 1877, Muybridge set up 12 cameras at the Sacramento racetrack to photograph a galloping horse. He stuck the images on a rotating disc and shone a light through them. Not only did it prove that a galloping horse sometimes has all fours off the ground, but the photographic technique became the basis for the movie camera.
Also see: First projection of an image on a screen