Why is there something rather than nothing?

I am well enough read to have a solid basis for the belief that much, or even, all of religion is superstitious. Clearly, belief in the various doctrines of christianity, for example, require serious and even delusional departures from reason. Yet, there is a profound mystry in the fact that there is a rational universe. The universe after all conforms to the laws of physics, it is in that sense rational. While certainly, I see no necessity to interject a "personal god" to account for this rationality any more than I see a need to personalize mathematics or physics. Nevertheless, the existence of a rational universe is totally mystifying. Why it should be so is hardly answered by what I believe Chris Dawkins wrote, which was somewhat to this effect: "nothing might be unstable and hence that may account for why there is something rather than nothing". I also find the muti universe hypothesis unsatisfying, namely the theory that out of an infinite number of universes, this one has "law" compatible with human existence--hence explaing why it is we are here (an anthropological view). This argument, of course, begs the question of how it is there can be rationality anywhere in however many cosmological schemes that may exist---besides the anthro type arguments really don't answer anything. such arguments, in my opinion, are to the athiest what St Anselm's lame ontological argument is to the believer. My question then is while one may be foolisih to believe in idea of a personal god---what adequately addresses the reality of a rational universe?
Atheist Answer: 

Nothing yet adequately addresses the reality of a rational universe, Jack, not even gods.

You're a little too focused on the multiple-universe hypothesis. It's not intended to be authoratively substituted for Creation myths in the same way as the theory of evolution can be substituted for religious accounts of the origin of modern animals. There's really no evidence for it yet, whereas evolution is supported by vast amounts.

The point of infinite multiple universes in these discussions is that there is at least one conceivable alternative to the hypothesis that an intelligent being created this particular universe to exact specifications, and therefore the theistic or deistic view cannot be presented as the only possible way. It's the standard response to the classic argument from ignorance, or as Dawkins puts it, the "argument from personal incredulity".

In simple terms, theists will often try to prove the existence of gods by pointing to something amazing and rhetorically asking, "How else could that possibly have happened?" The obvious response, in general form: "Like this, for example." Multiple universes are one such "this".

One other alternative hypothesis which serves the above purpose is that the universe is eternal in both directions, going back before the Big Bang. This removes the need for it to be created, or to emerge, or whatever, at all. Again, no evidence yet, but not impossible and therefore lethal to any attempted proof by elimination of a god's necessity.

But let's go in another direction. We'll take your stated view a bit further and reject as implausible (though not impossible) any unintelligent, undirected origins for our universe conceived so far, including the multiple-universe idea.

Where does that leave us? With an intelligent or directed origin, facilitated by an entity which can be satisfactorily described as a god. But then where did the god come from? If no undirected origin will suffice for a collection of matter and energy capable of behaving rationally (in the absence of a clear definition of "rationally" in this context, I would have used "predictably"), what undirected origin would suffice for a fully-formed intelligent entity with the unimaginable power and knowledge required to start (and, for a theist, maintain) a rational universe? Such an entity would be even harder to make without directed labour!

One solution to this is to posit an even more powerful entity to make the god; let's call it an uber-god. If you do this, however, the uber-god itself has to have been brought about by an uber-uber-god, and so on. An infinite regress is set in motion, and we're soon drowning in ubers.

Another solution is to posit an undirected origin for the god, or a lack of origin in the case of an eternal god. But what such solution cannot then be applied directly to the universe, eliminating the necessity of the god and making for a simpler hypothesis all round?

The origin of the universe is a profound mystery indeed. It remains so because the god hypothesis is an inadequate explanation; it requires an even grander explanation for itself, or it forces you to find a viable alternative which can then replace it.

- SmartLX

(This is an excellent follow-up question to two of the Great Big Arguments. Read them here and here for some background.)