The Black Hole story continues with our Black Hole merch, spanning the whole range from somewhat bonkers to more serious. Check it out here: Sources & further reading: The largest things in the universe are black holes. In contrast to things like planets or stars they have no physical size limit, and can literally grow endlessly. Although in reality specific things need to happen to create different kinds of black holes, from really tiny ones to the largest single things in the universe. So how do black holes grow and how large is the largest of them all?