The only one I've ever noticed on my own in a long life of watching movies is the compressed air tank to overturn a chariot in Gladiator (2000).<p>I was told about the pole that causes the truck to flip in Raiders of the Lost Ark and now I can't unsee it.<p>—Warning to those who enjoy 2001 A Space Odyssey with their blinders on...—<p>2001 made a big impression on me as a kid and I've seen it many times. There was a point when watching for the Nth time in middle age that I first noticed that all the anti-gravity shots show the actors bodies carrying their own weight. Especially in the aisle scene with the floating pen, which itself is rotating about the center of the sheet of clear plastic it's attached to rather than its center of mass. Later in the same sequence, food trays are brought to the bridge after the long scenes of a flight attendant, who picks up trays as they slide downs from a dispenser, and as she hands the trays to the crew, one of them instinctively puts his hand out under the tray to helpfully catch its weight. In the next scene an officer joins other crew by coming up from behind them, leaning over and resting his arms on their chair backs as the scene cuts to details of anti-gravity meal consumption. Finally Floyd stands in front of a toilet reading a 1000 word hard-printed list of instructions after the viewer has been shown electronic displays used everywhere else. The self-consciousness of that clip provides a lovely relief from all the previous cognitive dissonance. I'm not able to unsee any of this now and it detracts from the spectacle. But at the same time, it makes the orchestration and ideas of the movie seem all the more artistic, so nothing lost except innocence. There are many other oddities to find in the movie working on different planes of awareness, including proprioceptive assumptions about reality, intelligence, progress, and spirituality.