timdiggerm said:

What if I devise an equation which, if calculated, results in a number which, when converted to binary, would be a valid file which, when played in VLC, would show the movie? I then delete any copies of the film, but keep the equation.

Well you would still have a copy of the film. The difference would be that your equation would be sort of a parametric representation of the film as opposed to pixel-to-time mapping. Where ever you would put that equation to (paper, hard disk) it would still be a physical copy.