If you visited Google's home page today, you might have noticed the latest Google doodle — an animation of a man riding a horse that's meant to honor Eadweard J. Muybridge, who was born 182 years ago today. Muybridge is best known for creating the zoopraxiscope, one of the first motion picture devices. Muybridge famously used the zoopraxiscope to prove that all four of a horse's legs left the ground while it gallops, and today's Google doodle pays tribute to his work by displaying an animation very similar to the one he created back in1878. To prove that all of a horse's legs left the ground, he used multiple cameras to take a series of photographes of a horse in a gallop; the horse trigged each camera as it passed. After developing the photos, he had them copied onto glass plates as silhouettes, which were then able to be projected through his zoopraxiscope — both proving the theory and making the zoopraxiscope a precursor to modern motion pictures.