Natural Philosophy. Something must be eternal. If there was ever a time when nothing existed then nothing would exist now. Why is there something rather than nothing? The answer is that something has to have existence as an attribute (an unchangeable characteristic). You can go with multiverse theory or with God. they seem to be the only viable alternatives at this point. God has a far superior explanatory power than multiverse. The universe is full of information, this suggests an intelligence behind everything we observe. Try investigating that for a start.