Rutherford said that "all science is either physics or stamp collecting." In his view, a field either explains the underlying mechanisms of the universe (physics) or it simply collects and labels data without real understanding (stamp collecting).

Carr was saying, in a hand-wavy way, that we'll see a step-change in technological advancement when AI innovation in physics bears fruit, and that other applications of AI are less likely to be as transformative.

I wasn't quite sure what he was about there. I think there are a couple of different things - firstly AI making a breakthrough on the fundamental laws say combining quantum mechanics with gravity which would be interesting but I don't think was really what he meant. The other thing is using robots and the like to produce better and more stuff which I think he was thinking about though that's more engineering really.