My experience and knowledge of Set Theory is pretty lacking, so I apologize if I don't seem very assertive while discussing this topic. Anyhow, this is a big picture question that I have found to be, among other things, difficult to analyze: If the number of sets containing subsets is infinite, then how can a universe exist, since in claiming that such a set exists, we are claiming that it is the final set, thereby contradicting Set Theory? I don't know how to approach this question, nor am I even sure that it is valid since Set Theory tends to deal with the abstract, not the physical. Still though, if mathematics and logic can be simplified into sets, which many believe (proven?) and mathematics is one of our greatest tools used in describing the physical behavior and patterns found within space-time, can we ignore a question that carries with it such heavy implications? You start with the empty set,  which is a subset to all sets, then you move on to the set containing the empty set,  and from there it goes on and on, with each additional set containing all of the previous sets. If numbers are sets, and the mechanisms of physics are carried out in conjunction with numbers (mathematics), then is our ideal version of the "universe" as a set containing all other sets of matter and energy, one that is not itself contained by a greater set, incorrect? Oh, and just a side thought: could this be used as an argument in support of the Multiverse Theory?