Kant limits the sublime to an experience happening in the subject. An experience that can't be probing or cognitive. You can't, for instance, experience the sublime when you look at the ocean if you begin to think about all the lifeforms that swirl and thrash around in there. If you look at space, you can't think about the planets and black holes and possible “rational beings” up there.
In short, you can't speculate in the Kantian sublime.
This is the subject of my Speculations essay. Kant polices the sublime, saying that if you speculate with it, you become a fanatic, mad with reason. And we wouldn't want that! Too revolutionary? I like Kant enormously more than Burke, for whom the sublime is just shock and awe (to use Bush II's phrase for the bombing of Baghdad): the terrifying might of authority. At least Kant supported the French Revolution.