Monday, November 26, 2007

It's the law!

There's been quite a lot of reaction to a New York Times op-ed by Paul Davies titled Taking Science on Faith. (I read about it first on Adventures in Ethics and Science.) Davies argues that, like religion, science is ultimately based on faith. My main interest is not in his argument per se (but see here for some scathing critiques).

What struck me about Davies' essay was his use of the term scientific law. He uses it again and again, whereas he refers to a theory only twice, and not once does he refer to a model.

If there are laws, then presumably there's a lawmaker, and the obvious candidate would be God. If we are able to discover these laws, then we have identified Truth. Who can then disagree? Who can go against the law?

This seems to me a very arrogant notion. In fact the history of science is littered with "laws" that have subsequently been overturned or shown to be special cases or approximations. For instance, Newton's laws of motion (one of which, incidentally—his 2nd law, F=ma—is actually a definition) were superceded by special relativity and quantum mechanics.

Aren't scientific "laws" more accurately described as theories, or—my preference—models? I've previously quoted statistician George E. P. Box:
All models are wrong, some are useful
I would concede that in principle, it may be possible to get a model exactly right, but except in the case of a computer simulation, it isn't possible to be certain that it's right! To me, Box's aphorism is humble, epistemologically wise, and profoundly scientific.

It is my impression that for many years now there has been a movement in science away from the word law, with its implicit suggestion that the Truth has been definitively uncovered, and that somehow any deviation from the law is improper or even unimaginable. Nevertheless, use of the term continues (see the Wikipedia entries for scientific law, physical law, and laws of science). It might be argued that I'm reading too much into the word law. But consider how it affects schoolchildren who are learning about science. Rather that encouraging the idea that science is about curiousity, observing, investigating, and testing, I think it suggests that science is about memorizing rules.

Laws of chance

There is another class of "laws" that aren't exactly scientific, but still have an empirical aspect. In probability and statistics, it was at one time common to refer to probability "laws", the most famous being the curiously-named normal law. Today we refer to it as the normal distribution, or better yet the Gaussian distribution. The term "normal law" is a bit of a double-whammy: to go against it you would have to be abnormal and lawless!

Two fascinating "laws" relating to probability distributions are Zipf's law and Benford's law. I think that what makes probability distributions seem like "laws" is that they often hold—at least approximately—under quite general real-world conditions.

Law-abiding citizens

Why are we so prone to label models (among other things) as laws? I think it might be related to our abhorrence of uncertainty. For a law-abiding citizen, laws are a source of security. Everything seems neat and tidy and safe and predictable. But every so often, the world is revealed to be a bit different from what we expected. Maybe the laws don't work so well after all ...

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3 Comments:

Anonymous Mohammed-TA said...

I concur.

Our understanding of reality(ies) can at best be an approximation. It is a product of our logic, knowledge, and tools, and all three have not evolved enough to leave no room for improvement. So how can the product of something not absolute be absolute?

However, regardless of whether we can identify it/them, is there at all an absolute reality(ies), law(s), and logic to our world? I am inclined to believe there is .... simply because there is our world, our universe.

On a side note, faith, as I understand it, is achievement of inner certainty and removal of doubts. One simply can't get rid of it if one must hold an understanding.
A scientist observing DNA establishes faith in it. But the believing (in DNA) majority merely has faith in the scientist (a non-empiric evidence for most individuals) -- trust on evidence or evidence of trust, for trust can't be done away with. So, does not even science propagate on the wave of faith?

5:56 PM, November 28, 2007  
Blogger Nick Barrowman said...

Mohammed,

I tend to agree that there is an absolute reality, which to me means an external physical world that exists independent of my perceptions of it. I also believe that it has structure and regularity (i.e. "laws"). Science has made considerable progress in learning about that structure and regularity, and our models are getting better and better. I think of it as an asymptotic process. In the words of the Danish polymath Piet Hein: The road to wisdom? / Well, it's plain / and simple to express. / Err and err and err again, / but less and less and less.

Faith may very well be "achievement of inner certainty and removal of doubts". But that strikes me as more than a bit scary. Whereas a little knowledge is a dangerous thing, a lot of faith may be a dangerous thing—that is, unless you happen to be right.

So, does not even science propagate on the wave of faith?

No, science propagates on the (radio) wave of CBC's Quirks & Quarks.

11:09 PM, November 28, 2007  
Anonymous Mohammed-TA said...

Nick if I may slightly disagree:

"Whereas a little knowledge is a dangerous thing, a lot of faith may be a dangerous thing"

Little knowledge (or ignorance) is not a dangerous thing -- we all have little knowledge compared to all the knowledge there is to be had. Same goes for faith.

However, what is dangerous is to assume that what is not faith (true certainty with no doubts -- e.g. I am because I am)is faith....and by the same token to be ignorant of ones ignorance. In other words, truly an ignorant is not one who is ignorant but one who thinks she/he is not.

What this boils down to is the fact that we are so involved in challenging others , that we do not have time for our own introspection -- questions like how certain am I? what alternative explanation? What does it really mean? What am I missing here? etc. etc...

7:14 AM, November 29, 2007  

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