Wednesday, February 9, 2011

The Job of Science

What is the job of science? In other words, what can we expect science to do? Are there fundamental limitations to the kinds of truths that can be discovered by science – or can science even discover truth at all? These are extremely philosophical questions, but also extremely important for the practicing scientist, as their answers can influence everything from how one approaches a problem to how one presents the results. They are also extremely controversial. Realizing that all reasoning needs principles from which to reason, I will take for this article's principles that God exists, that He created the universe, and that He absolutely, infallibly, and solely revealed Himself in the Christian Bible and not through any other means. In essence, our listing of truths will begin with the truth of the Bible.

So, we take by faith that the Bible and nothing else is revealed truth, and we assume this as our starting principle for deduction. What about unrevealed truth? That exists, too; the Bible tells us that God established the physical world (Gen. 1) and its laws (Prov. 8:29, speaking of the “limit” and “command” that apply to the sea). These physical laws are ultimately true, but they are not in the Bible; therefore they cannot be revealed truth. (Note that, in this context, when I talk about physical laws, I mean not the 'laws' that have been formulated by fallible mankind to describe the universe, but the ultimate laws formulated by God to control the universe. Obviously, we don't know these ultimate laws.) Hence, the ultimate laws are unrevealed truth.

But can science find this truth? I maintain that it cannot. For science is a human endeavor, and humans are notably imperfect; therefore science is also imperfect. And an imperfect endeavor cannot lead us to perfect knowledge, which is what we would have if we knew the ultimate laws. Most likely the ultimate laws are beautiful and simple to the Mind that can comprehend them, and perhaps we will be told them when we get to heaven – or even better, maybe we will be allowed to discover them as an act of worship. But whether or not we ever know them in heaven, we will never know the perfect ultimate laws on imperfect earth. This may seem depressing, but it has a bright side: science will only stop when we know the absolute final laws of the universe, so if that is impossible, scientists will always have a job!

If science can't find ultimate truth, what can it do? Quite a lot, it turns out. The job of science is simply this: to allow humans to make predictions about the world, which can then be used to help fulfill the Dominion Mandate (Gen. 1:28).1 Basically, the job of science is to create models. Whether these models are as simple as a diagram of a lever or as complex as the quantum model of the atom, they are the beating heart of all true scientific endeavor. Note that the goal of these models, to fulfill the Dominion Mandate, does not mean that no scientific study should be done unless there is already a use in mind; on the contrary, some of the most useful things we know of, such as electricity and magnetism, were studied for hundreds of years before any significant use was made of them, but those many years of study were essential in gaining the knowledge necessary to invent, say, the hand-cranked emergency flashlight. Pure science is just as God-honoring as applied science.

Our situation can be compared to that of a man in a large room, extending as far as the eye can see, with many ropes hanging from a mysterious black box on the ceiling. He pulls one rope and hears a sound. Being a curious fellow, he decides to pull several ropes. Each time he hears a different sound. He pulls ropes in combinations; he pulls them hard and soft; he holds them for short and long times. After a while he begins to imagine a mechanism inside the black box that is ringing a set of bells. Perhaps he sketches this mechanism in a notebook. He sees that, if this is really the way it works, that rope over there – that blue one – it ought to produce a very low note. He pulls the blue rope; he hears the predicted tone! He checks further predictions, and they are confirmed. He has produced a model. After he has checked his model some more, he decides to walk further away. To his surprise, a rope that ought to produce a clear, high note actually makes a deep organ-like chord. He wonders: is his model wrong? But how can that be, since so many ropes fit it? He eventually realizes that all ropes within a certain area fit it, but the ones outside do not. He can produce another model for the ropes further out, but it contradicts the description of the black box that works for the inner ropes. This doesn't bother him too much, though, because he knows he may never find what is really in the box, but can only describe how the ropes and sounds seem to behave. Maybe later he discovers a model that makes the right predictions for both the inner and outer ropes; excellent! That is easier to work with. After long exploration, he finds a very puzzling region with no perceptible pattern. Actually, there is one idea that seems to work, but it is absolute nonsense: it claims that there are little fairies flying inside the box, and certain of the ropes have higher amounts of fairy dust. Of course, there are no fairies inside that box or anywhere else! What shall he do? But then he recalls that his models do not purport to explain what is really in the box, only what seems to be in the box based on how the ropes and noises behave. So, it's all right to use a model that would be philosophically unacceptable if it claimed to be a description of what really occurs, as long as everyone is clear that it cannot be what really happens, but can only give accurate predictions. Often the more reasonable models are also better predictors, but in the absence of a model that is “better” philosophically, a model based on “fairies” can and should be used.

What is the moral of the tale of the man and the ropes? The man represents scientists; the ropes represent physical phenomena, and the pulling of the ropes represents experiments. The black box represents the ultimate laws of the universe, and his models of what is in the black box represent the sets of 'laws,' or models, produced by science. The regions where the different models work represent the spheres of applicability of models in science; for instance, Newtonian mechanics is applicable for large objects moving slowly, but not for very small or very fast objects. “Fairy models” represent ideas, such as the lack of definite properties in quantum mechanics, that may seem incompatible with revealed truth but make excellent predictions.

We started this article with the questions, “What is the job of science? Can science discover truth? If not, what can it discover?” Our answers, based on the assumption that the Bible is the only revealed truth, were these: The job of science is to produce workable models2 that can make predictions and be used to fulfill the Dominion Mandate. Science cannot discover absolute truth, but it can state that a certain part of the observed world behaves as if certain 'laws' really were the ultimate laws. Science may not be able to discover truth, but it's certainly a worthwhile undertaking!

1 Those who have studied using Bob Jones University Press's science textbooks, to which I am indebted for many of my views on the role of science in the Christian life, will recognize the use of science to obey the Dominion Mandate.

2For more about the definition of workability in models, see this paper's companion paper, What Should We Ask of a Theory?