Wednesday, December 14, 2005


There was an interesting article by Jim Holt in Sunday's New York Times Magazine about science and it's ability to explain the world around us. At the end of the article, Holt refers to "a minority view" called instrumentalism. In this view, "scientific theories do not yield a true picture of a mind-independent reality; they are merely useful tools that enable us to predict our experience and have a measure of control over it." He then questions this view, quoting the famous scientist and writer Richard Dawkins; "do we accord for science's 'spectacular ability to make matter and energy jump through hoops on command' if not by assuming that the world, deep down, is more or less the way science tells us?"

I think this misses the point completely. Scientific theories are, by definition, explanations that have been demonstrated to predict behavior of the world within the scope of the assumptions of the theory. In short, theories are approximations of reality. But that shouldn't be a surprise to anyone who's taken high school physics. Do you really think a point mass exists? No. But it is a useful approximation of some objects that can lead to simple theories about how they move.

In fact, all of engineering is based on the premise that you make assumptions about the operating environment and use the appropriate theory to reasonably predict how the system will behave. Examples abound: air is not incompressible, but at low speeds it's close enough so we can use linearized aerodynamic equations to build very real airplanes; there is no such thing as a true voltage source, but it models a battery pretty well if you don't try to draw too much current.

A theory provides a means to understand some behavior using a testable, predictable structure. Who cares if the world is deep down the way the theory says it is so long as the theory provides a sufficient explanation for what we can observe in the world. But what happens when we observe things in the world that contradict what the theory is? Do we abandon science and just chalk it up to some intelligent designer? No. We look for a better explanation. That's what Einstein did when people realized Newtonian physics couldn't explain the world completely. But, we don't abandon Newtonian theory because for those of us who live in the slow moving world, it explains thing simply and reliably. What is important to understand about scientific theories is the assumptions and limitations that they possess. Only then can we know when to correctly apply a theory or where to aim future research.

On an end note, I would also like to renew my objection to using the phrase "science teaches us." Science does not teach us anything, people do. Science is a method, a procedure, a framework from which we can explore the world. It is not some mystical oracle or font of knowledge.


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