Sunday, January 31, 2010

Faith and Science

I was listening to a very nice talk by Ken Miller, from Brown University. He's the Biology professor who testified in the Dover Evolution Trial. The reason that he is involved in cases involving the attack on evolution from the religious right is several-fold, including his knowledge of evolution (even though that is not his main area of expertise) and his widely-used textbook (which was the target of the warning labels in Georgia). Ken Miller keeps a page on evolution and his own webpage with many links, presentation slides, and talk videos. I think the most important reason for his involvement is that he is a self-acknowledged Christian (a Catholic, to be specific). Rather than inviting an expert like Richard Dawkins (who is decidedly anti-religious) to testify, it is much better to invite someone who claims there is no conflict between religion and science. Thus the case can't be cast as a battle between science and religion, and can be seen only as what is appropriate science education.

So in his talk, Ken Miller makes the point that science should inform faith and faith should inform science. He cites Paul Davies, a physicist who has an interest in theism, and whose article "Taking Science on Faith" takes the position that science itself is a faith-based activity. Ken Miller points out, and you can confirm in Paul Davies' article, that there are two tenets in science that are taken on faith:

  1. the universe is ultimately knowable and understandable
  2. knowledge is better than ignorance
At first I thought that one perhaps should call these axioms, more like mathematics, and not "faith" because something in me felt that these two ideas were different somehow than the belief in God. Then, I realized, that they are different fundamentally and faith, or even axioms, is entirely wrong.

The first idea, that the universe is knowable, needs to be a bit more specific: what does it mean to be knowable? Prior to 1900, it was believed that the pieces of a physical model, such as the force of gravity, or the electric and magnetic fields of Maxwell were "real": there was one-to-one correspondence between the model components and things in the real world. Thus, it was believed, that knowing the model you would know nature. After 1900, with the advent of quantum mechanics, physical models were evaluated based on their predictive value: those models that predicted well were good models. It was not believed that there was necessarily a correspondence between the model components and the real components in nature. Aspects of the model, such as the wave function, were not believed to be real but simply useful in making predictions. To know the world is to be able to predict what would happen.

Let's say we replace "understandable" with "predictable", a replacement which I think makes practical sense (how else would you determine that you understand something?), and is directly in line with modern physical thinking. Doing this, then tenet (1) ceases to be an axiom, or something we take on faith, but is observable. If the universe is unpredictable, then all attempts at making prediction will fail. This is not what we observe at all. Surely there are still things that are unpredictable, such as the simultaneous value of the position and momentum of the electron, or the positions of every molecule of air in this room, but even there we can make specific predictions about average quantities or the values of other variables of interest. Practically, the universe has demonstrated itself to be understandable, on the whole. This is not a matter of faith!

The second tenet (2) I would wager is too vague. What does "better" mean? Better for whom, or for what? Psychologically, one might argue something akin to "ignorance is bliss", and there might be something to that. If we define, however, "better" to be higher standard of living (longer, healthier, more free life) then knowledge can be argued to have a demonstrable benefit over ignorance. The results of science has doubled the life expectancy in the past 100 years, and has allowed us to live more free and healthy lives. The thousands of years of faith before that cannot say as much. As Carl Sagan says, science delivers the goods. Is there any convincing argument that ignorance is better, or that we really can't decide which is better? Is there a preferable definition of "better"?

4 comments:

  1. I have been reading your blog but just couldn't find a minute to respond.

    In short, I really like this post.

    As you may or may not know, I'm a double major in Environmental Science and Global Studies (aka International Affairs/Relations). Though people generally argue, or are at least confused about, my choice to double major, the more I study, the more I find they have in common.

    In this particularly post, I think the two majors are easily intertwined. Currently, I'm taking a class on International Ethics. Still in the process of laying the stage for the rest of the semester, we've been discussing morality, primarily: where it comes from, how do we judge ethical action, and is international politics an arena for ethics? We've delved into a debate on whether morals come from circumstance or from universal truth, and who should have that say.

    On that note, I now consider your post on religion and science. I believe everyone has the right to make well-informed decisions. Providing students with science (truths or at least an educated attempt to find the truth) is essential to lead a well-informed life. However, is my belief based on my circumstances or my inner knowledge of universal truths? If the former, then do I have the right or authority to impose this idea on others? Even if I am successful in imposing my idea and people are informed, I can't force people to MAKE informed decisions without jeopardizing other liberties.

    I forget where I was going with this... I've literally been writing this post for days because (as I said earlier) I haven't had the chance to sit down. I'll add more to this when I have a second chance

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  2. Hi Dr. Blais...

    First time reader (following The Google from your PyMC post). Interesting post...some quick comments:

    After 1900, with the advent of quantum mechanics, physical models were evaluated based on their predictive value: those models that predicted well were good models. It was not believed that there was necessarily a correspondence between the model components and the real components in nature.

    I've always read Steven Weinberg's (1992) Dreams of a Final Theory as explicitly taking a realist stance about the entities posited by theoretical physicists.

    In any case, I think it might be a mistake to equate "knowable/understandable" with "predictable". Certainly scientists have assumed the universe was knowable long before we were taking predictability as our metric of success. It seems to me that this usage of "knowable" is more in line with a statement like "there is a Truth about the universe and Science leads us (more or less) inexorably toward it". And I think it might not be far off the mark to call that a statement of faith, as it's rather mysterious how we might go about proving it (of course, that's likely to just be a failure of imagination on my part).

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  3. Welcome to the blog, Fred!

    I've not read Steven Weinberg's book, but I tend to lean more toward Leon Cooper's perspectives, like http://www.physics.brown.edu/physics/researchpages/ibns/Cooper%20Pubs/076_SourceandLimits_84.pdf

    "knowable" is more in line with a statement like "there is a Truth about the universe and Science leads us (more or less) inexorably toward it". And I think it might not be far off the mark to call that a statement of faith, as it's rather mysterious how we might go about proving it

    I have heard a similar argument which says that inductive reasoning is unfounded, because you could only prove it works by inductive reasoning. I tell my students that proof only exists in math and philosophy. In science the best we can do is evidence, stronger or weaker. If it works, you're more confident in it. If it doesn't, you're less confident in it or more confident that it is wrong. You're right that people have assumed that the universe is knowable long before they took predictablility as a metric, but when they *didn't* use predictability as a metric they weren't as successful!

    Perhaps there are other metrics, but I can't think of any others that are consistent. Certainly if you know something, then you can predict it. If something, like science, moves you more towards the "Truth", then you must be able to predict more about the universe. There may be other things you can do, but prediction I think is a necessary consequence of knowledge, and it is nice as a check to see if you actually have knowledge.

    Some people say they know God, does that mean that they can predict God? Yes, to some degree. They will admit that they don't know God's whole plan, but they will state that prayer will lead to improvements (on average) and other things like that. Of course, all of these things that are claimed are either shown to be false (e.g. efficacy of prayer) or are content free (e.g. not a real prediction) and are untestable.

    Finally, I've never been swayed by the realist perspective for the simple reason that there are many different models for the same thing in physics, with different important quantities. Which are "real"? For a ball falling do down we have forces (Newton's Laws), energy (principle of least action), space-time geometry, gravitons and strings. Are any of these real? QM and General Rel make no reference to forces, quantum gravity makes no reference to geometry.

    Is there even a measurement of what is "real"? Is it even a testable question?

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  4. Just to be clear, I am not denying reality, nor am I saying that science doesn't say important things about reality. :) All I am saying is that there can be components of a model that are not necessarily directly observable, even in theory (ie. the wavefunction) and thus one would be hard pressed to refer to them as "real".

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