SCIENCE AND RELIGION
The following article is from Free
Inquiry magazine, Volume 22, Number 4.
The human brain is not at its best when it confronts random, merely accidental facts. We perceive a face on Mars or see Jesus in a burnt tortilla. We believe basketball players get a "hot hand" even though streaks of success are a normal part of shooting their usual overall percentage. If disaster strikes us, we wonder if there was some cosmic reason we were singled out.
Our religions also feed on this aversion to accidents. If evolutionary biology suggests our species was coughed up by a process of random variation and selection, theologians assure us a divine purpose was guiding everything behind the scenes. And then there is one of the
most intuitively appealing reasons to suspect there is a God. We can ask, why does this universe exist, among an infinity of possibilities, including nothing at all? There is no naturalistic answer; our sciences take us as far as
they can, and then we just have to say our universe has no further cause. It could have been otherwise, but ours just happens to be the one we live in. But never mind just us; this whole universe can't be just an accident, can it? There has to be a cause behind it all, says the classical cosmological argument, and if physics cannot produce it, so much the better. The world must have a transcendent cause-God!
The cosmological argument sounds reasonable, even after philosophical critics point out that it is not quite ironclad. Basically, it makes common sense. However, since we also seem predisposed to see cause and pattern where there are none, we should look a little closer at the notion of randomness before jumping to conclusions. Let's examine particularly modern physics, which has replaced
the Newtonian clockwork order with a world awash in randomness.
Randomness in Physics
Randomness most famously appears in quantum mechanics. Here we have an extremely successful theory that, as far as we can tell, describes how the world works at the most fundamental level. And it gives us probabilities, not definite predictions. The results of quantum measurements are random. Events in the quantum realm happen at random, including, for example, particle-antiparticle pairs popping into existence out of nothing and vanishing again.
Of course, quantum physics is also notoriously weird, and we might take the random fluctuations of the quantum realm to be yet another aspect of its overall strangeness. But randomness also shows up in other fundamental theories. For example, general relativity. At the boundaries of space-time, we find randomness. What comes out of the Big Bang is a roll of the dice. Black holes destroy information and emit thermal noise.
It may still seem that these are exotic matters at the limits of our knowledge, though physicists take them very seriously. But even our everyday lives are touched by the fundamental randomness
in physics. Consider the existence of good old-fashioned heat, long known to be a consequence of microscopic disorder. Or entropy, the increase of which keeps track of the gradual disordering of the universe, establishing the "arrow of
time." The nature of our everyday world is closely tied to the randomness in microscopic physics.
Now, this does not quite fit the popular image of physics, where theoretical geniuses contemplate the sublime symmetries of nature, grasping elegant laws of nature where beauty becomes truth. Einstein thought that a superior intelligence was revealed in "the harmony of natural law"; randomness seems to introduce an ugly messiness into these rarefied realms.
But even here, randomness is central. The ideal of a physicist is a set of equations that can fit on a T-shirt and generate all interactions between elementary particles based on abstract symmetry principles. However, equations on a T-shirt would contain very little information; they would say remarkably little about our universe. Our particular world would have to be generated through "symmetry breaking," where our low-energy world is frozen out through a series of accidents. In other words, elegant symmetry principles specify what sort of dice were rolled to produce our world. Symmetry and randomness are inseparable, the way the symmetry between heads and tails is essential to the randomness of a coin flip. And the more simple and elegant our most fundamental laws, the more this means our world is a result of accidents.
So it comes as no surprise that physical cosmologists today are comfortable playing with ideas such as universes popping into existence at random, somewhat like a particle-antiparticle pair or multiple "bubbles" of universes in which different low-energy laws of physics operate because the roll of the symmetry-breaking dice turns out differently in each. After all, random, uncaused events appear to be the rule in physics - why should physical cosmology be different?
Though it may offend common sense, randomness reigns in modern physics, particularly in our most fundamental theories. If we look a bit more closely at what randomness means, we find this is no accident.
Where Explanation Ends
We may still be tempted to rally common sense and object to this talk of uncaused events. Randomness, we may think, is merely a label for our ignorance of true causes. If we encounter randomness in our fundamental theories, this is only because this is where the current limits of our knowledge stand, and so we have not yet figured out the deeper causes.
Liberal religious thinkers tend to think this way. Their God is hidden; he is not some tinkerer who directly intervenes in the world, but he is also not absent. The seeming accidents of evolution and physical cosmology all have a purpose-to create humans, perhaps. In fact, something like quantum indeterminacy may be just the device for a God to tweak the outcome of cosmic evolution without crass intervention; something not possible in a Newtonian clockwork universe.
Unfortunately, none of this really works. Consider a series of coins arranged in an alternating pattern of heads and tails, "HTHTHTHTHTHTHT. . . ." This is not random: we can easily predict the next coin in the sequence, and provide a simple rule for the sequence. But if we flipped a fair coin, we would end up with something like "HTTTHTHTHHHHHT . . .," a series with no overall pattern at all, where it is impossible to predict the next toss. All we can do is list, as a brute fact, whether the result of each toss is T or H: no rule will help us simplify our description. In the long run, the series will have plenty of local patterns, but like the Face on Mars, these will be meaningless.
The randomness in physics is exactly like this. Physicists do not declare randomness lightly, going on initial ignorance. They attempt to find patterns, including causal connections, and judge something as random only after failing and seeing no prospect of finding an overall pattern on closer investigation. If something is random, we cannot identify a pattern to link it to a network of causes. Randomness, in other words, is where explanation ends: when we cannot give further reason for how something is as it is, when we can do no more than say it is a brute fact.
This does not, of course, prevent the metaphysically inclined from inventing hidden causes behind randomness. Some philosophical interpretations of quantum mechanics do just this. However, these causes do no real work: all the calculations remain the same, and the randomness is still there, only displaced from the dynamics itself to the initial conditions. The difference is that between rolling the dice on the spot and looking up random numbers from a predetermined but hidden table. In other words, there is no way to legitimately infer a cause behind what appears random. If something is random, this means that at some level it is uncaused.
In fact, if we really want to take modern physics seriously, we should go further. We have traditionally thought of a world that works by cause and effect as a fundamental assumption of science, even as a presupposition of rational thought. But in modern physics, ordinary causality breaks down in the microscopic realm. Not only do we have events that happen at random, there is no distinction between forward and backward directions in time. Our familiar, macroscopic sense of cause and effect is, like the arrow of time, not something basic to the world. These both emerge in our macroscopic environment, out of a microscopic substrate that is radically different.
Again, all of this is quite offensive to common sense. But then, it has long been clear modern physics is counterintuitive. Our brains just aren't built for it. It also seems crazy that our world just exists, with no cause, as an accident. Nevertheless, this seems to be most likely true. Ours is an accidental world, a chaos that finds shape without the help of the gods.
Taner Edis is assistant professor of physics at Truman State University, and
author of The Ghost in the Universe: God in Light of Modern Science
(Prometheus 2002), upon which this article is based.