Why is there something, instead of nothing?

Why is there something, instead of nothing?

Philosophers are always pondering such questions like why is there something instead of nothing (thanks Jason Fraze for the question prompt) I don't think that this is really an answerable question.

However I would like to ask the question is there such a thing as nothing? In other words is there a place in the universe that is totally devoid of an existent thing?

After spending much too long on the subject I have concluded that no, nothing cannot exist. (In my proof I will prove that non-beings cannot exist, nothing is a subset of the non-beings set).

Proof:

Suppose that there are actually two possible classes of things...beings and non-beings. Assume that a set of non-beings exists. These non-beings are defined in that they are the compliment of the set of all things that are beings (In other words non-beings have no existence). But the set of non-beings is definable. And all things that are definable have a reality (however limited their reality is). But this is a contradiction in that non-beings must not have a reality for they are the compliment of all things real. Therefore by the law of non-contradiction, a non-being, or a nothing cannot be said to have existence or reality.

So what does this mean in practical reality? I'm not sure, but it brings a few thoughts to my mind that there cannot be such a point in history that nothing existed. So at the very least the Big-Bang theory falls short in explaining the universe. For even prior to the Big Bang, there was something. And before that there was something, so on ad infinitum. What is the answer to this "infinite regress" as Aquinas called it? God.