2001: A Space Odyssey is a film about a series of encounters between humans and mysterious, yet advanced machines built by an unknown alien species that are affecting human evolution. The characters in the film go on a space voyage to Jupiter tracing a signal emitted by one of these machines. You would expect the physics in this movie to be good considering it’s a “science” movie and you’re not wrong. However there are some areas where you can find bad physics. In general, the film does a good job of respecting the laws of physics. In this review, we’ll look at good and bad examples from some scenes that happen on the spacecraft during the voyage.

Good Physics:

When the stewardess is walking with the “grip shoes” up the circular wall and then on the ceiling. This scene is scientifically accurate because; since there is no gravity, there is no sense of direction. This means that being “upside down” is irrelevant due to the fact that there is no difference between upside down and right side up in space. The stewardess would feel completely normal either way. As for the “grip shoes”, there is no scientific reason why they couldn’t work. They would allow her to stay planted in the surface. Although there is no normal force or artificially gravity, the grip shoes keep her from floating off the surface every time she pushes off to take a step.

When the astronaut is jogging around the giant circular section of the spacecraft, it is an example of good physics because of centripetal force. He does not need “grip shoes” here because this section of the spacecraft is actually spinning to create the illusion of gravity. In reality, its not gravity that he’s feeling, it’s an inward force that the floor exerts on the man as a result of the craft spinning in a uniform circle. Just like in the other scene with the woman and the “grip shoes”, since there is no real gravity, there is no sense of direction. So “upside down” does not technically exist. Wherever that man is in that section of the spacecraft, as long as he was touching the floor, he would feel normal thanks to the artificial gravity

In one of the camera shots of the spacecraft cruising through space, we see that the engines are off. This is scientifically accurate because the ship wouldn’t need to have its engines on to maintain speed. There is no friction or air resistance in space so the ship can technically coast to its destination once it has reached a desired speed. Many movies with space ships always show the ship with the engines always running (probably because it looks cool to have blue flames coming out of the back of the spacecraft). But in reality, all that would do is cause the craft to accelerate indefinitely, making for a rather unsafe trip.  

The last scene I will analyze is my favorite for two reasons. This is the scene when the person comes out of the pod and into the spacecraft. There is good physics in this scene because before he closes the hatch, there is no sound. This is scientifically accurate because there is no medium for the sound to travel through, which explains the dead silence. This is a concept that many moviemakers are not aware of; or more likely, tend to ignore; especially when depicting explosions in outer space.

Bad Physics:

Unfortunately, the last scene I mentioned in the good physics section also has some of the worst physics in the movie (in my opinion). One of the reasons this part is bad is because the man holds his breath while floating in the airless, pressure less section of the craft. In reality, he would explode rather spectacularly because the pressure inside of his body is much greater than the pressure outside his body.

Another scene with bad physics goes back in the scene with the rocket engines being off. If you noticed, the light is hitting the spacecraft from the left. However the right side of the craft is still pretty well lit. In reality, the side with no light source would completely pitch black because in space, there is nothing for light to reflect off of. So only the areas in direct contact with light would be lit up.

Despite the major problem in the escape pod scene, and the minor problem with the lighting, this film does a very good job of obeying the laws of physics.