Monday, April 10, 2006

Physics and Emergence

I'm going to ramble along the lines of the conversation that Rob and I have been having in the responses to recent posts below. I'm not sure exactly what I'm gonna say but let's get started.

The way one is trained in both physics and engineering is by learning from simplified examples. Concepts are taught from the most basic, fundamental representation. Then the problems at the end of the chapter are just one or two steps of complexity above that. For instance, to learn kinetics, what happens when two objects collide that are going at different speeds and directions, we start with infinitely hard billiard balls that are perfect spheres and do not absorb energy from each other. There are other background assumptions we won't go into. There is no spin involved and no friction with the surface on which they sit. Everything is idealized. There is good reason for starting in this way. We must start first with the simple and get practice in order to learn the concepts and make sure we understand what we are doing.

There is a well known joke about this. A physicist was once asked to consult with a farm regarding a herd of cows that was not producing enought milk. After studying the problem and determining his solution, the physicist went to the blackboard to explain to his customer, saying "First, we assume a spherical cow..."

That's the end of the joke and everybody laughs.

But, when we get jobs and go out into the real world to solve real problems, all the easy things have been done. The equations get complicated. The machines we work with are not ideal spheres or cylinders and cannot be described by simple equations. Mathematical models are constructed. Data collected, the models are corrected and provided with "fudge factors" to make them work so they make the right predictions enough of the time to be useful.

The problems to be attacked in this way are many. But, we can only do simple machines and circuitry this way. And some simple fluid dynamic problems. Mechanical and fluid flow devices follow the rule's of Newton's mechanics. With electrical devices we use not only Maxwell's electromagnetic theory but quantum theory as well.

But, as great as physics and its subset of mechanical and electrical engineering is, it is pretty useless for telling us what a living cell is doing and what it will do. With such a complex, higher order system, new laws apply. I'm guessing emergence theory tells us that the with the higher complexity, new order and new phenomena have emerged which exert control over the lower. When we progress from single cell life to multicellular life, the next level, the new entity exerts control (supervene's) over it's cellular constituents. At some point in the appearance of life, consciousness appeared, that is, the ability to feel and experience. Now, it is the highest level.

postscript: I watched the special on the Gospel of Judas on the National Geographic channel last night. Enjoyed that. But, can't say that GJudas has anything new to tell us either about the real Jesus or the real Judas. Perhaps, it highlights that we really don't know that much about the latter.

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