It seems so improbable now that 2001: A Space Odyssey was an actual hit fifty years ago, but it was the single biggest movie of 1968. This is strange because no humans appear for the first half hour, and when they do show up they barely speak. The original cut of the film was three hours long with an intermission, though eventually it was cut to a little under two and a half hours. You could say that attention spans are shorter now, but Renata Adler’s 1968 review acknowledges that the study of astronauts being tormented by a possibly gay supercomputer falls “somewhere between hypnotic and immensely boring… the uncompromising slowness of the movie makes it hard to sit through without talking,” she says, noting that people did, in fact, talk the whole time. Other publications of the time acknowledged that the audiences were largely stoned on psychedelics, too. It’s playing in IMAX for its 50th anniversary.