The following argument by Nathanial Branden does, I think, counter successfully ANY "creationism" or "big bang" idea: "FIRST CAUSE" IS EXISTENCE, NOT GOD

Question: Since everything in the universe requires a cause, must not the universe itself have a cause, which is god?

Answer: There are two basic fallacies in this argument. The first is the assumption that, if the universe required a causal explanation, the positing of a "god" would provide it. To posit god as the creator of the universe is only to push the problem back one step farther: Who then created the god? Was there still an earlier god who created the god in question? We are thus led to an infinite regress - the very dilemma that the positing of a "god" was intended to solve. But if it is argued that no one created god, that god does not require a cause, that god has existed eternally - then on what grounds is it denied that the universe has existed eternally?

It is true that there cannot be an infinite series of antecedent causes. But recognition of this fact should lead one to reappraise the validity of the initial question, not to attempt to answer it by stepping outside the universe into some gratuitously invented supernatural dimension.

This leads to the second and more fundamental fallacy in this argument: the assumption that the universe as a whole requires a causal explanation. It does not. The universe is the total of that which exists. Within the universe, the emergence of new entities can be explained in terms of the actions of entities that already exist: The cause of a tree is the seed of the parent tree; the cause of a machine is the purposeful reshaping of matter by men. All actions presuppose the existence of entities - and all emergences of new entities presuppose the existence of entities that caused their emergence. All causality presupposes the existence of something that acts as a cause. To demand a cause for all of existence is to demand a contradiction: if the cause exists, it is part of existence; if it does not exist, it cannot be a cause. Nothing cannot be the cause of something. Nothing does not exist. Causality presupposes existence; existence does not presuppose causality. There can be no cause "outside" of existence or "anterior" to it. The forms of existence may change and evolve, but the fact of existence is the irreducible primary at the base of all causal chains. Existence - not "god" - is the First Cause.

Just as the concept of causality applies to events and entities within the universe, but not to the universe as a whole - so the concept of time applies to events and entities within the universe, but not to the universe as a whole. The universe did not "begin" - it did not, at some point in time "spring into being." Time is a measurement of motion. Motion presupposes entities that move. If nothing existed, there could be no time. Time is "in" the universe; the universe is not "in" time.

The man who asks, "Where did existence come from?" or "What caused it?" is the man who has never grasped that existence exists. This is the mentality of a savage or a mystic who regards existence as some sort of incomprehensible miracle - and seeks to "explain" it by reference to non-existence.

Existence is all that exists, the nonexistent does not exist; there is nothing for existence to have come out of - and nothing means nothing. If you are tempted to ask, "What's outside the universe?" - recognize that you are asking, "What's outside of existence?" and that the idea of "something outside of existence" is a contradiction in terms; nothing is outside of existence, and "nothing" is not just another kind of "something" - it is nothing. Existence exists: you cannot go outside it; you cannot get under it, on top of it, or behind it. Existence exists - and only existence exists: There is nowhere else to go.

-- Nathaniel Branden.