Oppenheimer and Star Wars
For a long time now I have sustained that Star Wars is not science fiction - and indeed it isn't. Based on the same criteria, neither is Oppenheimer a movie about science - at least, not explicitly. Science Fiction Science Fiction is a specific genre. Although it lacks an exact definition, it usually involved the exploration of Mankind's "future", based on scientific concepts.
@volkris The Death Star is a valid point. However, keep in mind that the Death Star itself was never a plot point in the movie; the plans for it were but they could be substituted by any number of McGuffins. The fact that the story - which really revolves around the eternal strife between Good and Evil - happens in a technologically advanced environment is trivial, because the same story could be told in any other context (e.g. medieval Japan).
That's fair, and yeah I thought it was kind of a close call, and I did have to think a little long to come up with that scifi angle :)
@volkris Foundation for example is a story that isn't transferrable to another historic context. Its story cannot be directly transposed to a less advanced stage of human history (for example). It's centered about the science of psychohistory and the reactions of people to it.
Another example would be Star Trek, which is centered around warp travel, contact with alien species and the technological future of Mankind. Transferring it into a non-technological context would ruin its main argument.