All of the special effects footage had to be printed on the original negatives. Stanley Kubrick thought using copies of the negatives would harm the visual quality of effects shots.
Although all advertisements, as well as the soundtrack album and the movie's closing credits, claimed that the film was released in Cinerama, it was not shot in the Cinerama process (three synchronized films that would be shown by three synchronized projectors on a huge, curved screen). All Cinerama films from 1963 on were shot by one camera on 70-millimeter film with a special anamorphic lens that would then project a blown-up image onto the curved screen. This film initially did such poor box office that MGM actually considered pulling it from Cinerama release after completion of a 30-day run. The exhibitors began reporting that audiences were not only increasing, but it was noted that some audience members had come to see the film multiple times. It eventually became one of MGM's biggest hits, yet was the only film to be pulled from Cinerama venues while it was still making a good profit. Metro-Goldwyn-Mayer was anxious to release its completed production Ice Station Zebra.
Although it's commonly believed that the famous "jump cut" is from the bone being tossed in the air to a ship floating in space, it is in fact not a spaceship, it's a nuclear device circling the earth. So the bone being used as the "first" murder weapon is thrown to the "ultimate" weapon. Originally the "star child" was to detonate this device and all the other devices that were circling the earth. Stanley Kubrick decided against the ending as it was too similar to the end of his previous film Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, where nuclear bombs are exploded.
Although the memories of many Los Angeles residents insist that this opened at the famous Cinerama Dome on Sunset Blvd., it actually opened at the Warners Cinerama Theater on Hollywood Blvd., and played there for months. It did not play at the Dome for several years.
Among the model-makers was David Peterson, later Wales's foremost sculptor and a prominent nationalist activist.
An early draft of the script had narration.
Aside from the film's music, no sound is heard in the space sequences. This is because technically in space, there is no sound.
At the end of the film, the only spacesuit that was never used is the blue one. In 2010, the blue suit is missing its helmet, apparently because the producers thought that Dave used it in 2001: A Space Odyssey when disabling HAL. Dave is actually wearing a green helmet, from the green suit which was stowed inside the emergency airlock.
By the year 2001 some of the product placements had become outdated. RCA Whirlpool, the maker of the zero-gravity food preparation unit on the moon shuttle, had become Whirlpool. The Bell System had been divested and the long-distance service became AT&T. Pan Am had ceased operations as an international air carrier (in fact, the Whirlpool change had already happened by the time of the film's original release).
Despite its G-rating, there are five on-screen murders: a man-ape, Frank Poole, and the three hibernating astronauts killed by HAL. The dialogue also includes the words "hell" three times and "damn" twice.
During the trip Bowman takes after leaving the Discovery, some of the images seen are tinted footage of the Isle of Harris in the Outer Hebrides.
Evidence of Stanley Kubrick's attention to detail: there are visible replacement instructions for the explosive bolts in the ejection apparatus of the pods.
Frank Poole and Dave Bowman watch themselves in a television interview on "BBC 12". This was a play on the fact that, at the time of production, there were only BBC channels 1 and 2. The presenter in this scene is Kenneth Kendall, the first newsreader seen on British TV in 1955.
HAL 9000 never once says, "Good Morning, Dave," despite this line being one of his most recognized quotations.
HAL sings "Daisy Bell" (or "A Bicycle Built for Two") as he is shut down. One of the earliest pieces of electronic music, this was the first song ever programmed into a computer to be played back using a simulation of speech synthesis. The machine was an IBM 7094 that was located at Bell Labs in 1961. Furthermore, the lyrics include the phrase "I'm half crazy."
If you consider the relative positions of Bowman when he first arrives in the suite, when he is next standing in the room, when he is in the bathroom, when he is at the table, and when he is in the bed, these points form a star.
In honor of the book and movie, NASA named a Mars orbiter: 2001 Mars Odyssey. This was not the first time NASA had a connotation with the film; the Apollo 13 command module's callsign was Odyssey during the ill-fated mission.
In the French version, Dr. Heywood Floyd's middle name is Richard.
In the novel version of 2001: A Space Odyssey, Arthur C. Clarke used the Latin spelling J instead of I, for the Saturnian moon of Japetus.
In the premier screening of the film, 241 people walked out of the theater, including Rock Hudson who said "Will someone tell me what the hell this is about?" Arthur C. Clarke once said, "If you understand '2001' completely, we failed. We wanted to raise far more questions than we answered."