This film is indubitably the greatest science fiction movie ever made. Up to this very day after decades since it's release it still sits comfortably at the top of the list. It's haunting, awe inspiring, astounding, and limitless. There is very little human interaction and character development. There is no focus emphasized on any single character really while all the characters that are addressed and given space are simply conveyed as the representatives of the human race itself.
Stanley Kubrick uses images and sounds as the focal points to tell his story. The pace is slow and the images are given a considerable amount of time so that they can establish themselves into the recesses of our minds for us to ponder upon even long after the film is viewed. The classical compositions are sometimes ominous while at others convey a sense of majesty and glory applied critically to give more dimensions to the scenes. The scenes themselves may come across as tedious at times but sit through it, pay attention, and think well into it later, and you will discover the brilliance of Kubrick's direction.
The subject of the film is the evolution of man. Certain mysterious monoliths are the creative pieces Kubrick puts to convey alien presence. The mystique of the monoliths are carried to the very end of the film and their significance may well be lost on a casual viewer who may find himself frustrated that such central elements of the story are not explored enough to establish their importance in the film. The first time a monolith appears, it triggers a thought process in the apes who are confronted with it and are surprised and captivated by its unnatural existence, which is different from anything they have seen upto that point. This thought process leads to the conclusion that a bone can be used as a weapon. The second time a monolith shows up, mankind has advanced to the point that they can land on the moon, discover and excavate it by themselves. This one serves as a pointer to Jupiter and tantalizes humans to explore the connection. The third one is a wormhole. The final monolith appear after a period of comprehension, and serves the objective of ultimately transcending humans to the level of cosmic intelligence. They appear at turning points in human history as catalysts for change. They are placed at critical junctures in the story where their mystique influences evolution. The great artist Botticelli in the final page of Dante's paradiso where he was supposed to sketch God, instead left it blank . His justification being it's best for that image to be filled individually by the readers rather than impose his own vision on them because perfection is subjective. In a likewise fashion, Kubrick never shows the aliens but uses the monoliths to convey their superiority , presence and mystique. And precisely because of this execution, the viewers reactions to the existence and actions of these extra terrestrials are extremely strong and will forever be a giant invisible presence in our minds.
2001: A space Odyssey and it's message will forever be limitless and open to interpretations like a Mark Rothko painting. To me personally, it ends on a very positive note where the potential for human evolution is conveyed as still incomplete but potentially would reach a status of cosmic intelligence should we choose to recognise and repair the many intrinsic human flaws and accept that our intelligence and consciousness shouldn't be wasted and rather be focused elsewhere to ensure our progress as a species.