But we can have an explanation, which can be falsified by arguments, without needing to directly test the inside of black holes with instruments.

> Now my reply to instrumentalism consists in showing that there are profound differences between "pure" theories and technological computation rules, and that instrumentalism can give a perfect description of these rules but is quite unable to account for the difference between them and the theories.

I think that's the right quote, Popper often lets me down when I want something terse and uncomplicated.