Please help! I read a statement by Lee Smolin (Time Reborn) that an "open" infinite universe necessarily has a "boundary", through which information would be received, which he used as an argument that cosmological models should prefer a "closed" universe approach. In fairness, he said that this was "counterintuitive", but... Huh? Why a boundary in an "open" infinite spacial universe? I obviously don't understand this concept correctly.