Science is an atheistic enterprise. As the eminent population geneticist J. B. S. Haldane said:

My practice as a scientist is atheistic. That is to say, when I set up an experiment I assume that no god, angel or devil is going to interfere with its course; and this assumption has been justified by such success as I have achieved in my professional career. I should therefore be intellectually dishonest if I were not also atheistic in the affairs of the world.

While not every scientist would apply the highly successful atheistic methodology to every aspect of their lives as Haldane does, the fact that intellectual consistency requires it, coupled with the success of science, has persuaded most scientists that leaving god out of things is a good way to proceed and hence it should not be surprising that increasing awareness of science correlates with increased levels of atheism.

But it would be wrong to conclude that scientists have atheism as a driving concern in their work or that they actively seek out theories that deny the existence of god. God is simply irrelevant to their work. The negative implications for god of scientific theories is a byproduct of scientific research rather than the principle aim of it. Non-scientists may be surprised that discussions about god are almost nonexistent at scientific meetings and even in ordinary interactions among scientists. We simply take it for granted that god plays no role whatsoever.

For example, the idea of the multiverse has torpedoed the argument of religious people that the universe must have had a beginning or that its parameters seem to be fine-tuned for human life, which they argue are evidences for god. They seem suspicious that the multiverse idea was created simply to eliminate god from these two of the last three refuges in which he could be hiding. (The third refuge is the origin of a self-replicating molecule that was the precursor of life.) In his article titled Does the Universe Need God?, cosmologist Sean Carroll dismisses that idea.

The multiverse is not a theory; it is a prediction of a theory, namely the combination of inflationary cosmology and a landscape of vacuum states. Both of these ideas came about for other reasons, having nothing to do with the multiverse. If they are right, they predict the existence of a multiverse in a wide variety of circumstances. It’s our job to take the predictions of our theories seriously, not to discount them because we end up with an uncomfortably large number of universes.

Carroll ends with a nice summary of what science is about and why god really has no reason to be postulated into existence. This is similar to the points I made in my series on why atheism is winning.

Over the past five hundred years, the progress of science has worked to strip away God’s roles in the world. He isn’t needed to keep things moving, or to develop the complexity of living creatures, or to account for the existence of the universe. Perhaps the greatest triumph of the scientific revolution has been in the realm of methodology. Control groups, double-blind experiments, an insistence on precise and testable predictions – a suite of techniques constructed to guard against the very human tendency to see things that aren’t there. There is no control group for the universe, but in our attempts to explain it we should aim for a similar level of rigor. If and when cosmologists develop a successful scientific understanding of the origin of the universe, we will be left with a picture in which there is no place for God to act – if he does (e.g., through subtle influences on quantum-mechanical transitions or the progress of evolution), it is only in ways that are unnecessary and imperceptible. We can’t be sure that a fully naturalist understanding of cosmology is forthcoming, but at the same time there is no reason to doubt it. Two thousand years ago, it was perfectly reasonable to invoke God as an explanation for natural phenomena; now, we can do much better.

None of this amounts to a “proof” that God doesn’t exist, of course. Such a proof is not forthcoming; science isn’t in the business of proving things. Rather, science judges the merits of competing models in terms of their simplicity, clarity, comprehensiveness, and fit to the data. Unsuccessful theories are never disproven, as we can always concoct elaborate schemes to save the phenomena; they just fade away as better theories gain acceptance. Attempting to explain the natural world by appealing to God is, by scientific standards, not a very successful theory. The fact that we humans have been able to understand so much about how the natural world works, in our incredibly limited region of space over a remarkably short period of time, is a triumph of the human spirit, one in which we can all be justifiably proud.

Religious believers misuse this fundamental nature of scientific inquiry, that all conclusions are tentative and that what we believe to be true is a collective judgment made by comparing theories and determining which one is best supported by evidence, to make the misleading case that unless we have proved one single theory to be true, other theories (especially the god theory) should merit serious consideration. This is wrong. While we may not be able to prove which theories are right and which are wrong, we do know how to judge which ones are good and which ones are bad.

God is a terrible theory. It fails utterly to deliver the goods, and so should be abandoned like all the other failed theories of the past. In the film Love and Death, Woody Allen’s character says, “If it turns out that there is a god, I don’t think that he’s evil. I think that the worst you can say about him is that basically he’s an underachiever.” He is right.