there's no way to express coherent concepts in things like Ptolomy's epicycles or Aristole's impetus

There are perfectly fine ways to express those things. Epicycles might even be useful in some cases, since they can be used as a simple approximation of what's going on.

The reason people don't use epicycles any more isn't because they're unthinkable, in the really strong "science is totally culture-dependent" sense. It's because using them was dependent on whether we thought they reflected the structure of the universe, and now we don't. Ptolemy's claim behind using epicycles was that circles were awesome, so it was likely that the universe ran on circles. This is a fact that could be tested by looking at the complexity of describing the universe with circles vs. ellipses.

So this paradigm shift stuff doesn't look very unique to me. It just looks like the refutation of an idea that happened to be central to using a model. Then you might say that math can have no paradigm shifts because it constructs no models of the world. But this isn't quite true - there are models of the mathematical world that mathematicians construct that occasionally get shaken up.