This argument can also (but doesn't always, necessarily) draw on the fallacy of "specified complexity" as well; from wikipedia:
1. Nature exhibits complexity, order, adaptation, purpose and/or beauty.
2. The exhibited feature(s) cannot be explained by random or accidental processes, but only as a product of mind.
3. Therefore, there exists a mind that has produced or is producing nature.
4. A mind that produces nature is a definition of "God."
5. Therefore, God exists.
Note how the assumption stated in #2 appeals directly to the "specified complexity" fallacy?
But I digress. What I want to address is the fact that, yes, there is a scientific opening for something to exist beyond this universe. It is entirely possible that some force we have yet to discover is what set this universe in motion. However, let me clarify what I mean (and do not mean) by that statement:
1) I do NOT mean that there is room for a god that actively influences the universe today;since we are talking about a god that can (supposedly) be proven by science, I am going to address this from a physical perspective: our universe is basically one giant closed Thermodynamic System, and the law of conservation of energy tells us that energy can never be created nor destroyed, it can only be transferred. So by these laws, it is theoretically possible that our universe is not the only closed system that exists, but due to physical limitations, if there are other universes that exist, we can never interact with them physically because our spaces are not connected. So that's basically unknowable.
If there existed such a being as a god that acted physically, then this should be easily demonstrable --- any incident in which this god interacted with our universe would cause a disruption of the laws of physics, however temporary, that could be detected in some way (a sort of "supernatural footprint;" I want to attribute that term to Richard Dawkins, but I cannot find a proper citation, so I'll leave it uncredited for now).
Because the system of our universe is closed and stable --- which is to say, every system within it and every bit of mass or energy within it (along with all of their reactions to one another) is mathematically accounted for --- if some force were to intercept any of those processes, it would interrupt them in such a way as to disrupt what should be the natural, physical laws of interaction; such an interception would, in other words, cause things to behave in a way that should not, physically speaking, be possible. That point in time should, at least in theory, be detectable in some way.
On the other hand, if it is NOT detectable --- if the interactions of 'god' with the physical universe are indistinguishable from the natural laws, or if he does not interact with the universe physically --- then god's interactions are not provable by scientific means, because there is no way to tell whether a given event is simply the result of nature following the laws of physics, or of god working through the laws somehow.
Keeping in mind, it's possible that such a god could interact with the universe in a non-physical way --- if you wanted to argue for the existence of some other dimension of which we are not aware --- but I will not touch on that here because it is unknowable and thus not worth discussing from a scientific perspective. The argument I presented above only applies to a god whose existence can be confirmed physically.
2) I do NOT mean that any god of any specific religion exists;
Off the top of my head, I'll refer to Christianity here. The Christian god says that we were created 6000 years ago, at the same time as the planet earth, the universe itself, all life and all laws within it. We can demonstrate that humans and the earth are significantly older than 6000 years, and that many life forms have come and gone since the time it was created; the theory of evolution explains how all life on this earth has changed significantly since it first began, and various dating techniques (such as tree ring dating, carbon-14 dating for small periods of time, etc.) can be overlapped to give us a picture of a planet that is very old, indeed. Not even considering the age of the universe itself, the Biblical literalist account of Genesis has been demonstrated to be scientifically inaccurate. So as I understand it, it is impossible for the legends of Judeo-Christian origin to be literally, specifically true, given what we know about the planet and the universe. Therefore it would be odd to proclaim that the god who supposedly said these things exists. Some god may exist, and maybe he did say something to some humans somewhere which was recorded at some point, but it's possible that if he did, the humans got it very wrong or twisted it of their own accord. In any case, it's unknowable and therefore cannot be proven (or disproven) scientifically.
With that out of the way....
As demonstrated in the SMBC cartoon, it is possible, even for someone who is purely a materialist, to believe in a scientific "creator god" who caused the universe to begin to exist. However, the implications of using this as a proof for god's existence must be understood --- the god inferred by scientific necessity (the 'god' that may have created physics) would likely not be the same as any god claimed by any religion today. Such a god would probably not be personal, like the Christian god; it would not likely actively involve itself with the contemporary universe; the most that we can actually say about this god is that it exists, and that it must (by definition) be as energy, un-creatable and un-destroyable. If we do not assume that much, then it defeats the purpose to assume it in the first place, for we're left with the assumption that such a god can be created, can cease, and therefore had to have a creator itself who was infinite (to avoid an infinite regress of gods who were created by gods who were created by gods, and so forth).
No...a scientific 'creator god' has only two known qualities --- it created the universe, and it can neither be created nor destroyed. That second one may sound familiar; this is because it is also a property shared by the energy that exists in this universe. That's interesting, isn't it? Let's see how far we can extend that analogy without contradicting ourselves:
- God can not be created or destroyed; neither can energy
- Therefore god has always existed; energy has always existed, then, too
- God created the universe; so....did energy create the universe?
One has a slightly more scientific grounding if one wants to claim that energy itself is god, or some extension thereof. For energy seems to have all of the properties of god as far as its nature, and yet it also fuels the interactions within our universe. But notice if we extend the analogy further:
- Energy is uncaring, unfeeling and impersonal....so is god uncaring, unfeeling and impersonal?
- Energy is bound by the laws of physics and cannot behave uncharacteristically....so is god bound by the laws of physics? Can he behave uncharacteristically and defy his own nature?
Odd implications. But also strangely realistic; these are all very possible statements of god. In fact, in my arguments with apologist Christians like Frank Turek, I've been confronted with the argument that God can't defy or change his own nature, and that god essentially is equivalent with the laws of physics and the universe (i.e. the laws are part of god's essence or nature). So the more we extend the analogy, the more we begin to see god as a sort of "robot" (for lack of a better term), a being that does not make decisions, per se, but rather operates "on rails," doing whatever its nature commands it to do....much in the same way that the systems within our universe behave. Physics are not held in check by intelligent life; they run independently of it, obeying their nature and not changing. So could the same be true of god?
I'd tell you, but as an agnostic atheist, I believe god's existence (or non-existence) is ultimately unknowable. It's just something to think about, I guess @_@