Is There a Gap Between Knowledge and Knowledge?

i worry that you're performing a bit of a conjuring trick here. Why mightn't certain transformations of the material world be unachievable, even in the presence of complete knowledge? There definitely are gaps of that kind, and they are all laws of nature. For example, if we want to get to er the nearest star within a year, we can't do so because of the accident of where we happen to be. So i think this argument works because it's an explanatory one - but there isn't a whole other explanation for why these things aren't possible.