Saturday, April 21, 2007

more on Wendell Berry

I've been really appreciating this book of essays by Wendall Berry called "The Way of Ignorance". His basic examples come from agriculture and farming which he has experience with, but I can't help finding many parallels to physics.

His essay "Local Knowledge in the Age of Information" really solidified for me a good part of the reason (in a roundabout way) why I am in a national lab instead of trying to go directly to a university. He describes the need for conversation between the center and the periphery. He says that the periphery needs the center as much as the center needs the periphery. At the center, inormation is collected and efficient ways of representing and presenting that information is found. Life occurs on the periphery. Contact with the center can give one access to a wealth of experience from other places. But without conversation, the center loses its understanding that it owes its existence to the periphery, and the periphery loses its ability to ask for help and to gain useful information that will work within an appropriately local context.

Here's a (perhaps obscure) example given by a certain physicist that I work with. I think it provides a physics example Of Berry's point about the need for conversation and an illustration of what local knowledge looks like. Consider non-linear single particle dynamics in accelerators. The needs of this discipline involve predicting whether a particle in a certain non-linear system will stay within a certain region for very long or not (the dynamic aperture). Non-linear dynamical systems have been studied in other contexts as well. The gravitational n-body problem is an example from astrophysics. In that context, one wants to know, for example, whether our solar system will be stable over long time periods. The knowledge from this and other fields requiring the understanding of long term dynamics of non-linear systems has made it to the universities. Dynamical systems research collects together such knowledge. Now, certain theorems exist, such as the KAM theorem in which long-term stability criterion have been found. The problem is that the perturbations are just too big in an accelerator or a solar system for the theorems to apply. So, it may be that people in the universities think that in some sense the problem has been solved, wheras in "the field", the solutions are useless, and the very sense of arrogance implied in the attitude that the problem is essentially solved may at times do more harm than good.

Yes, this idea of conversation between the center and the periphery is very interesting to me, even if my example and explanation is rather murky at the moment.

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