By definition the suggestion to create multiple universes is ridiculous as the universe in a nutshell is defined as "all existing matter and space considered as a whole". I.e. it is everything that exists and could exist and contains all things we could perceive or not perceive. Something cannot exist outside of the universe. Onto the point in question, what existed before the big bang? Using my definition of universe theoretically it had to exist in some form to allow a big bang to be possible. The big bang postulates that everything at one time existed in a singularity, matter, energy etc. Nothing existed outside of that singularity (supposedly). So one could argue that this singularity was infact the universe. My problem arises firstly what actually caused seemingly dormant matter to suddenly explode and my second problem is what was the singularity actually expanding into? When i blow up a balloon it is possible because it expands into the space around us. However take that same balloon and try to imagine blowing it up outside of the proposed singularity, the notion is ridiculous. So if the previous statement is ridiculous it follows that for everything to be expanding (the singularity which was the proposed universal contents) surely there would have to have existed space in which the matter, time and space could expand into. A more appropriate view would be that actually the universe has always existed and will continue to do so but the state of the universe changes. Modern science puts emphasis on life having a start point (infinite regression). In a similar way to religion when causes causes cant be established; following the religious path leads to GOD, whilst the scientific path leads to the big bang.