Sunday, April 04, 2010

Aristotle vs. Newton

I took a Shabbat nap yesterday afternoon, and once again dreamed about an analogy between physics and religion which made sense at the time, and which I am now trying to reconstruct. This time around, I was fully asleep, rather than in the liminal space between asleep and awake. I'm not claiming this is the next "Kubla Khan", but putting it out there anyway.

Background for people who aren't living inside my head: The Aristotelian concept of motion was that forces cause motion. In the absence of forces, objects slow to a stop. This was supplanted by Newton's Laws: In the absence of forces, objects at rest stay at rest, and objects in motion continue in the same direction at constant speed. Forces cause a change in velocity. Yet it is well-documented in physics education research that many people continue to hold Aristotelian conceptions. This is understandable, because from our experience of the world, we are familiar with situations where a force must be continuously applied to keep something in motion, and in the absence of that force, the object slows to a stop. The Newtonian response is that, in such situations, other forces (e.g. friction) are acting on the object to slow it down, and the applied force is needed to bring the net force to zero, so that the object can move at constant velocity. Physics education must bring students toward the Newtonian framework, but must do so in a way that helps them make sense of their phenomenological observations within that framework, and should avoid (as Edward F. Redish and David Hammer of the University of Maryland write) "the negative epistemological side effect that students learn to consider their intuitive knowledge and lived experience as irrelevant for physics learning; they learn to set it aside, rather than to draw on and refine it." Toward this end, curricula have been developed (at UMD and elsewhere) that focus on "refining intuition", to (e.g.) reconcile the Newtonian ideas with students' observations that appear to support the Aristotelian framework.

So in my dream yesterday, I drew an analogy between these two paradigms (and educational approaches that bridge them) and God's role in the world. On the one hand there is the "Aristotelian" idea that God must be continuously acting in the universe in order for the universe to keep going. On the other hand there is the "Newtonian" idea that God had to act initially to get the universe going, but then, in the absence of a net force, the universe keeps going on its own. So then the big insight (which I don't entirely remember) was how to reconcile the "Newtonian" framework that the universe keeps going on its own with our "Aristotelian" experience that God is continuously acting in the world... or is it the other way around?


  1. What a dream for the Shabbat of Pesach!

  2. Seems like it's the opposite of the situation in physics. In physics, our natural intuition tells us that the universe is Aristotelian, with a force necessary to keep things moving at a constant rate, but on more careful consideration it turns out to be Newtonian. In theology, if you want to call it that, our natural intuition is that the universe keeps going on its own without God having to do anything except maybe occasionally, but on more careful consideration we realize that the universe is theologically Aristotelian, and what we think of as the universe running as its own is really God making the universe run according to its usual pattern.