The Godless Gaps

I wouldn't normally bother commenting on articles about cosmology and God, but this one is written by the inestimable actual cosmologist Ethan Siegel, so I'll make an exception.

My broad take is that science is in some ways agnostic and other ways antitheistic. Science presumes that observable natural phenomena can in essence explain themselves, that we can discover the mechanisms at work that explain the observable world through observation and testing. Following on from the previous post about knowledge, proposed explanatory mechanisms gradually transmute into observable facts. What begin as untestable or even apparently unknowable ideas are slowly brought into the realm of direct observation. 

For example, atoms were once just a purely philosophical speculation - no-one had any idea of their size, still less if they could ever be measured. There was nothing much of a physical, observational reason to suggest them at all. Later they became a more detailed theoretical construct that helped explain specific observations and made testable predictions, but only in recent years have they themselves become directly observable. The shape of the Earth underwent a similar change, as did the existence of the planet Neptune, evolution and the Big Bang - albeit with rather more uncertainty still hanging over that last one.

Obviously not everything has undergone this full process, or science and philosophy alike would be dead in the cold earth. Gravity has transitioned from being able to explain existing observations to being testable experimentally through interplanetary probes, but that which causes gravity is not yet a direct observable. Particle physics also has reached a stage where testing ever-smaller scales is becoming impossible with currently technology. Past developments might caution us not to assume that such capabilities will be forever inaccessible, so we might perhaps be more charitable to string theory and the like : just because it might take phenomenal energies to test is no real grounds to doubting its validity, only its experimental verifiability. 

At the same time, it might indeed be fundamentally impossible to directly observe the "fabric" of spacetime. Nothing is cut and dried. There might, perhaps, always be gaps.

Science has to presume that those gaps are not, however, the realm of God. It presumes that there must always be another aspect to reality that we have not yet discovered or interpreted correctly, such that observable phenomena are ultimately able to explain themselves. The difficulties posed by competing models and alternative interpretations only indicate that a subject has not yet reached the stage where it can be subject to direct observational test, but there are areas in which this has been achieved. The crystal spheres will not return. The Earth will never be shown to be flat.

So science is strongly antitheistic in this sense. Allow even the slightest possibility that "God did it" and the crack becomes a gaping hole that undermines, if not demolishes, the entire edifice. God could be suggested as the explanation for the tiniest anomaly or the smallest deviation from theory, much as "aliens" are frequently invoked by the less religious. No, where science finds a gap, it has to be content with - and even takes delight in - labelling it as an unknown. It denies that any presently inexplicable phenomena is the work of God.

But this is not the same as denying God itself. Denying each and every specific instance is still not the same as denying the general principle. At last it's time to bring in Ethan :

If you think about it rationally, it makes intuitive sense that something cannot come from nothing. After all, the idea that anything can come from nothing sounds absurd; if it could, it would completely undercut the notion of cause and effect that we so thoroughly experience in our day-to-day lives. The idea of creation ex nihilo, or from nothing, violates our very ideas of common sense.

But our day-to-day experiences are not the sum total of all that there is to the Universe. There are plenty of physical, measurable phenomena that do appear to violate these notions of cause and effect, with the most famous examples occurring in the quantum Universe. As a simple example, we can look at a single radioactive atom. If you had a large number of these atoms, you could predict how much time would need to pass for half of them to decay: that’s the definition of a half-life. For any single atom, however, if you ask, “When will this atom decay?” or, “What will cause this atom to finally decay?” there is no cause-and-effect answer... In fact, there are many interpretations of quantum mechanics — paramount among them the Copenhagen Interpretation — where acausality is a central feature, not a bug, of nature.

To assert that “whatever begins to exist must have a cause” ignores the many, many examples from our quantum reality where — to put it generously — such a statement has not been robustly established. It may be possible that this is the case, but it is anything but certain.

He also makes an interesting link between determinism and causality. Now I believe that everything must have a cause, and that if quantum mechanics says otherwise, this is pointing to some gap in our understanding, some incompleteness (rather than wrongness) in our science. But I'm not sure I'd subscribe to the idea that causality means the Universe is entirely deterministic. And I'm not at all sure how science can robustly accept the idea of acausality, or whether the whole concept of infinite time even makes any sense. That all... doesn't sit right. More on that in a future post, maybe.

Ethan goes on to note that the Big Bang theory does not necessitate a singularity - in fact, inflationary theory forbids it. 

Whereas a Universe filled with matter or radiation will lead back to a singularity, an inflating spacetime cannot. Not just “may not” but cannot lead to a singularity.  Remember, fundamentally, what it means to be an exponential in mathematics... That’s what inflation teaches us: our Universe, for as long as inflation went on, can only get smaller [going backwards in time] but can never reach a size of zero or a time that can be identified as the beginning... To assert that “the Universe began to exist” is completely unsupported, both observationally and theoretically.

Again, as before, a “Universe that came into existence from non-existence” is a possibility, but it is neither proven nor does it negate the other viable possibilities.

So cosmology suggests that the Universe didn't have a beginning, and therefore there is no need for causation to invoke it. And you can hardly have a Creator without a moment of creation. On the other hand, there are many caveats to that : these are theoretical models which hardly have the same rigour as the shape of the Earth, and nothing in them explicitly forbids a creation event. Nothing explicitly says the Universe cannot have begun at a singular point in time but of finite size and other physical conditions, i.e. to begin the same inflationary process as we observe, but with a discontinuity only in time and not in space. But let's push on a bit further first :

 [The necessity of God] is only defensible if you define God as “that which caused the Universe to come into existence from a state of non-existence.” Here are some examples that show why this is absurd.

• When we simulate a two-dimensional Universe on a computer, did we bring that Universe into existence, and are we, therefore, the God(s) of that Universe? 

• If the Universe’s inflationary state arose from a pre-existing state, then is the state that gave rise to inflation the God of our Universe? 

• And if there is a random quantum fluctuation that caused inflation to end and the hot Big Bang — the Universe as we know it — to begin, is that random process equivalent to God?

Although there would likely be some who argue in the affirmative, that hardly sounds like the all-powerful, omniscient, omnipotent being that we normally envision when we talk about God. If the first two premises are true, and they have not been established or proven to be true, then all we can say is that the Universe has a cause; not that that cause is God.

Here I must disagree, because I would be one to argue in the affirmative - in fact I find it strange that anyone would argue otherwise. If I create a simulated Universe, how am I not that Universe's version of a God ? I am omnipotent with regards to that simulation. With respect to that simulation, I have all the supernatural powers of a God - I can even be regarded as eternal, since I can alter the flow of time in that "universe". True, in my world I will age and die, but that's not the case from the perspective of any entities inhabiting my simulation - and for them that's all that matters. To them, I have characteristics which are literally and fundamentally beyond their comprehension or imagination.

Likewise, I think it's perfectly valid to describe the cause of the Universe as God. That argument is discussed at length in both Spinoza and the Upanishads. The definition of God needn't be confined to a traditional Western version. One version of God not as a moralistic beardy busybody but as a prime mover is that God is the solution to the infinite, the ultimate and final cause, the unknowable solution to the mystery of inescapable discontinuities. E.g., God is that which can create itself, or what causes eternal existence. Such concepts are ungraspable by the human mind, which God, by definition, is beyond. Personally I like this conception of God very much (which is not to go so far as to say I agree with it, mind you).

To return to Ethan :

In any scientific endeavour, you absolutely cannot begin from the conclusion you hope to reach and work backward from there. That is antithetical to any knowledge-seeking enterprise to assume the answer ahead of time... In particular, you cannot posit an unprovable assertion and then claim you have “proved” the existence of something by deductive reasoning. If you cannot prove the premise, all logical reasoning predicated upon that premise is unsubstantiated.

It remains possible that the Universe does, at all levels, obey the intuitive rule of cause-and-effect, although the possibility of a fundamentally acausal, indeterminate, random Universe remains in play (and, arguably, preferred) as well. It is possible that the Universe did have a beginning to its existence, although that has by no means been established beyond any sort of reasonable scientific doubt. And if both of those things are true, then the Universe’s existence would have a cause, and that cause may be (but isn’t necessarily) something we can identify with God. However, possible does not equate to proof. 

While I think science is antitheist in presumption, I think it is equally important that it be agnostic in potential. It should by default assume that God is not the answer. But if it rejects any possibility of God whatsoever, saying that God cannot exist because everything is physics, then that is circular and unscientific - just as it would be equally unscientific to use God as an explanation for everything.

It is quite sensible in everyday life to reason by induction and inference, to assume that patterns hold beyond their initial observations : lions are dangerous, therefore other animals with sharp teeth can also be assumed to be dangerous. But we would be wrong to hold this as proof. We would ordinarily be quite prepared to have our ideas subject to revision by new data. With any mystery, science should seek an explanation other than God, and indeed should reject the possibility that the answer is God... unless there is active evidence to the contrary. If a miracle-working deity descends from the clouds, at some point it becomes pretty silly to reject the possibility that it is in fact a divine supernatural being.

But is this notion of a Prime Mover just another sort of gap - the kind that science is forbidden from filling with God ? I would argue no. Where there are gaps in knowledge, such as not knowing if the hypothesised Planet Nine exists, science cannot invoke God. But here we have a gap of an altogether different kind, one that is arguably unavoidable : a gap unbridgeable by human thought. Can anyone ever comprehend a timeless or infinite existence ? No. It is not a matter of increased computational power, but something of the most fundamental kind of impossibility.

Just as the beings in my own personal simulated Universe couldn't understand my reality, so we could not understand God. This means the possibility of a simulator-like God is not impossible but rather reinforces the point that there is no reason to expect the simulation to be anything much like our observable reality. This is true even in our own simulations : we render them in a way that looks familiar, but the actual mechanics of what's happening in the computer - electrons moving around inside a chip - bears no resemblance to, say, the motion of a gas cloud or the fluid dynamics of an ocean. So our simulator God would be no less supernatural, after a fashion, than our traditional divinity - even if from the perspective of God itself, God is nothing very special. God might be a sort-of glorified computer programmer, yes, but this is to misunderstand the differences between a simulation and reality. God might well also be something utterly incomprehensible to us. Nothing about observable reality can give us any clue either way, unless God itself decides to intervene.

Science, then, is often antitheist but it is also profoundly agnostic. And perhaps most importantly of all, it should be apatheistic - to the unbiased observer, it does not matter if the evidence indicates a divine entity or otherwise. Whether God is the fundamental cause of two atoms colliding does not matter when it comes to understanding the mechanics of the collision. For science, God is not dead, just irrelevant.