The words "science" and "settled" probably should not appear together in a sentence. There always seems to be some little complication hiding in the details, such as the cosmic rays you mention, which are affected by the solar magnetic flux, which is somehow tied to the sunspot cycles, which may be in their turn tied to tidal effects from Jupiter and Saturn.
We never run out of things to study. That, at least, is settled.
Another case in point. Just last week, some scientists announced that the DNA in all human cells is NOT identical! My daughter just finished a bio sequence at the university and told me the instructor was drilling into their heads until the last day that all DNA in a human being is the same.