Harrison Ford actually outran the boulder in the opening sequence of "Raiders of the Lost Ark" (1981). Because the scene was shot twice from five different angles, he had to outrun it ten times. Ford's stumble in the scene was deemed to look authentic and was left in.
In filming the Well of Souls sequence, the producers scoured every pet shop in London and the south of England for every snake they could lay their hands on. Hence, there are snakes that are identifiable from many different geographical areas. However, once all the snakes were on set, it became clear that there were not nearly enough of them, so Steven Spielberg had several hoses cut into lengths, and these were used as well. Looking closely, you can tell which are the real snakes and which are not. Some of the weeds in the scene were lifted by Lawrence Kasdan from the Dagobah set of "Star Wars: Episode V - The Empire Strikes Back" (1980). A sheet of glass separates Ford and the arched (and highly dangerous) cobra when he falls in. The snake actually did spray venom onto the glass. Snake handler Steven Edge noted that unlike Indiana, Ford is not afraid of snakes.
Jones's hat came from the famous Herbert Johnson hat shop in Saville Row, London. The hat was the shop's "Poet" model. On the Bonus Features DVD, costume designer Deborah Nadoolman said that in order to properly age the hat, she grabbed and twisted the hat, then she and Ford both sat on it, and it eventually looked like "a very lived-in, and well-loved" hat.
"My playing Indy was mentioned to me about only six weeks before shooting started, but being second choice wasn't at all offensive. I would always assume that it would be normal for (George Lucas)- once having worked with an actor in a particular part - not to think of him for something else. I'd presume that he'd want to accentuate the difference between the two characters by having another actor. I was more than happy when they did ask me to play Indiana Jones, because it promised to be a terrific role in a great film."
Kubrick spent $750,000, a large portion of his $6 million budget for 2001: A Space Odyssey, on the set for the artificial gravity scenes in the carousel. The set was a vertically-mounted 27 metric ton circular set 38 feet (12 m) in diameter and 10 feet (3.0 m) wide. The entire set could rotate around its axis at up to 3 miles per hour (4.8 km/h). The rim of the carousel would move slowly enough to allow the actors to walk around with it as if they were in a hamster wheel. This created the impression that the actors were walking up the walls of the set, while in fact, the actors remained at the bottom. The same technique was used for the Aries Moon shuttle scenes.
Clarke believed that the ability to transfer between zero-g and artificial gravity areas of a spaceship would be easily learnt by astronauts, and this is how Kubrick portrayed it in the film. However, expert opinion is that this would be somewhat more difficult to achieve, particularly due to the Coriolis force. Long-radius centrifuge experiments by the Naval Medical Research Laboratory starting in 1958 kept subjects in a 30-foot (9.1 m) diameter centrifuge complete with living quarters for up to three weeks. The experiments found that the subjects took three to four days to overcome motion sickness and balance issues.