Everyone calls Thomas Alva Edison the father of film but he was actually more like a supporter. Before he could help popularize movies with the Kinetoscope, someone had to have the crazy idea of making movies in the first place. That wouldn’t happen until after the discovery of the phi phenomenon.

First explained in 1916 by psychologist and film theorist Hugo Münsterberg, the phi phenomenon is something that occurs in all of our brains when we watch films, and it is also the reason why the pictures on a film reel are seperated by frames. When the film stock rolls before a camera too slowly, you can see that each still frame is being seperated by darkness, but if you roll the film fast enough, the darkness vanishes and instead we see what appears to be continuous movement. This optical illusion known as the persistence of vision is the reason why movies do not look like a series of rapid still shots but instead look smooth and lifelike. When darkness follows an image, the light receptors in our eyes retain the image for a fraction of a second, but if another image replaces the darkness fast enough, it will look like a continuous action.

Münsterberg describes hallucinating an illusion of continuous movement by mentally and subconsciously filling in gaps as the phi phenomenon. The reason why we can watch films without being distracted by this phenomenon is the same reason why we can go about our day blinking without it disrupting our vision: it goes by too fast to be noticeable.

This idea was introduced to the public after Joseph Plateau invented the Phenakistoscope in 1832, which is an ancestor of the more famous Zoetrope, a circular spinning drum with pictures on the inside invented by William George Horner in 1834. Actually these discoveries were being made simultaneously by different men, primarily in France, England, Germany and the United States. Each country claims to be the birth place of film but all of them would make significant contributions.

The first person to break a continuous action into photographic units was actually an Englishman living in the United States. In 1872, Eadward Muybridge was hired by the governor of California, Leland Stanford, to help win a $25,000 bet that at some point during a racehorse’s stride all four hooves left the ground at the same time. In 1877, after faster exposures became possible, Muybridge set up 24 different cameras along the race track and proved Stanford right.

In 1882, the first person to shoot multiple pictures with a single camera (essentially the first person to actually “film” something in the modern sense) was Etienne-Jules Marey in France. In 1884, George Eastman, founder of the Eastman Kodak camera company, experimented with celluloid, which became the natural material for further experiments in motion picture photography in 1889.

Edison capitalized on the film industry around this time and he and his team of inventors helped launch it into the business that it is today.