>Looks like an astronomy problem to me. Aristotle is also considered one of the early astronomers.
I'm not sure what you're getting at here. My point was that Plato and Aristotle (and other early astronomers) realized that astronomy had to be based on observation. No-one (except perhaps a few cranks that no-one remembers) has ever tried to do "armchair astronomy".
>the ones that we have solved we now consider science, the ones that are still unresolved we consider philosophy.
I think the distinction is really just the distinction between empirical science and metaphysics, which is a distinction that Aristotle would also have made, though perhaps in slightly different terms. For this reason, I think the image of armchair philosophy gradually yielding ground to science is wrong. Broadly speaking, philosophers have always worked on philosophical problems using philosophical methods, and scientists have always worked on scientific problems using empirical methods. There hasn't been any great shift from one to the other. What has occurred of course is a shift in prestige: society currently values empirical science much more than it values philosophy.