The term "the universe is infinite" is inaccurate considering the fact that the universe is expanding. Definitions 1.)By definition, an "infinite set" is: a set whose cardinal elements are equal to the subset of the [infinite] set. 2.) By definition, the word "universe" is defined as "all that there is". 3.) By definition, "space" is the set containing all points. Thus interchangeable with "universe". 4.) By definition, "expand" is "To become greater in size, volume, quantity, or scope" If the universe becomes greater in size, then it is increasing the space which constitutes itself [the universe]. But can something infinite increase its size? I am pretty sure that it cannot; I am open to correction. Therefore, (assuming my aforementioned conclusion is correct) saying that "the universe is expanding" is illogical. Rather, "a finite subset of the universe is diffusing itself into the set containing the finite subset." Of course, that would be assuming that space does not neccesarily depend on occupying matter to exist, right? My reasoning is this: The universe is a set containing space which is the set of all points (thus including all of the cardinal elements of the universe) that if only the contents of the universe are expanding, then the entire universe should be too unless not all of space is expanding or only the occupied space is expanding. Another idea I have for this problem is this: If the universe is infinite and is expanding, this means that the way the contents of the universe are arranged is changing? Wait, I just got an idea (or rather a question): The universe cannot be infinite because it would converge to a limit, as in calculus, right? If my ideas are incoherent, please point that out so that I may try to clarify it. I just jotted this down because it has been on my mind for the past week, and I wanted your opinion on it. Thanks.