Throughout this thread, you've expressed your assertion that Big Bang cosmology requires an intelligent causal agent. Your assertion, however, has been based on a series of misconceptions about the Big Bang and the nature of the Universe as a whole, coupled with some unfounded assumptions and a few logical fallacies sprinkled on for good measure.
Let's start by pointing out that conceivability by a human brain is not a requirement for any aspect of the Universe. After all, there are stranger things in Heaven and Earth than are dreamed of in your, or any other, philosophy. There are many aspects of the Universe that are counter-intuitive to the human mind - and that doesn't stop those concepts from accurately representing the reality of the Universe. Human beings, after all, evolved on Earth, and our base of knowledge, our familiarity, is based on the limits of our own experiences. We cannot see atoms, we cannot see electrons, we cannot directly observe quarks, we have no experience that can relate to gluons. Galaxies and globular clusters and nebulae are, to us, just pretty pictures from telescopes.
Arguing that alternative hypotheses are invalid because they are "inconceivable" to your mind is nothing more than an Argument from Incredulity, a logical fallacy.
delve into the mysteries of the Universe, we need mathematics. And the math shows us that our experience of the Universe is, frankly, illusory.
You and I experience "time" as a constant-rate continuum of events moving in the direction of increasing entropy. We cannot go backward, and we have no control over its rate of passage (except through relativistic velocities in different inertial frames, but then, we can't actually do that at the moment either). We experience time this way because our brains are themselves entropy machines - our very thoughts require the passage of time in the direction of increasing entropy. That's how the electrochemical processes that drive our minds work. The consequence of this is an anthropomorphized concept of "causality."
To a human mind, we see all events as causes and effects, related points in a never-ending chain that make up the continuum of time.
But time is just another dimension, no different really than length, or width, or height. If you could experience the Universe independently of time, you would be able to see the entire course of your life as a set of interconnected events. You could look forward, or backward, and see the exact state of the Universe at any given moment. The Universe would appear unchanging,
So do causes, and effects. A "cause" is an event which precedes its effect in time. To be "caused," there must be an earlier point in time for the "cause" to occupy.
When we're talking about the Universe as a whole, were talking about time itself as well,
because time is nothing more than a property of the Universe, just like width, or length, or the total mass-energy it contains.
If the opening moment of the Big Bang was in fact T=0, the very earliest moment of time...then when would the "cause" occur? What time, exactly? T=-1?
The concept of an earlier moment in time than the first
moment, a "cause" for the beginning of time itself,
is literally as meaningless as conceiving of a point further North than the North Pole. The concept ceases to make sense to human intuition.
The reality of the first moment of time is that all of our predictive models break down in that first moment. The Universe was too hot, and too small, and too massive for any of our current observations to relate to. The math simply breaks down.
So the real answer, here, is that we don't know
much about the reason
the Universe exists.
Perhaps the Universe was inevitable. Perhaps "existence" is favored over "nonexistence." Perhaps there are infinite Universes floating in some extra-Universal space-like dimension. Perhaps reality exists as a probability field, and the Universe we experience is simply the result of the most probable series of events. Perhaps the Universe hatched from an egg. Perhaps an extra-Universal intelligence, using technology we cannot even yet imagine, created the Universe. Perhaps one of these, or one of an infinite number of alternative hypotheses, explains the origin of our Universe.
The honest answer is that we don't know.
What we do
know is that our concept of causality breaks down when we talk about the origins of the Universe itself, just as the concept of the direction "North" breaks down when we start talking about movement in outer space.
Big Bang cosmology tells us only that, as you look through time, the Universe exists in different states. The farther back you go, the smaller all of the spacial dimensions become, while the mass-energy of the Universe remains the same. If we trace the trend all the way back, we arrive at a point where our ability to mathematically describe the Universe breaks down.
That's all. It does not
even tell us if those so-far-indescribable moments (typically called the Singularity, which is just physics-speak for "we don't know what's going on here with any reasonable degree of accuracy") were the actual
beginning of the Universe...or whether our concept of "beginnings" even has relevance.
These open questions and uncertainties are why we continue to study the Universe, why we create such facilities as the Large Hadron Collider to duplicate as closely as we can the conditions of those first moments, so that we can develop the math to describe them.
But the Big Bang does not
support the idea of a religious "god" as a creator any more than any
other hypothesis. It doesn't contradict
any of them, but then, what would? A magic omnipotent Creator could just as easily Create a static
Universe, one that does not appear to have a beginning. After all, the vast majority of physicists were still religious before the discovery that the Universe is expanding.
If there is
a god, the Big Bang doesn't help us see it. It would look the same to us, either way, given the information we currently have.
"Failing to contradict" is not the same as "supporting evidence." Evidence
needs to adjust the relative probability of accuracy among competing hypotheses...and nothing about the Big Bang increases the likelihood that there is a deity beyond competing hypotheses that are also
The human understanding when it has once adopted an opinion (either as being the received opinion or as being agreeable to itself) draws all things else to support and agree with it.
- Francis Bacon
"There are two novels that can change a bookish fourteen-year old's life: The Lord of the Rings and Atlas Shrugged. One is a childish fantasy that often engenders a lifelong obsession with its unbelievable heroes, leading to an emotionally stunted, socially crippled adulthood, unable to deal with the real world. The other, of course, involves orcs." - John Rogers