03 August 2005

Modern Physics: Some Analogies.

Just to make the point about emergent physical phenomena clear, and to make my terminology clear, I'd like to use a chess analogy.

We know most of the rules of the game. There are a couple we're not quite sure about. We don't know what happens if a pawn makes it all the way to the other end of the board, indeed, while we note that the distances moved by pieces seems to be pretty consistent, we're color blind and actually can't see the squares on the board. We're not sure if a King can capture pieces, as we've never seen it happen, although we hypothesize that it can. We don't know for sure how the board looked when the game started, but we have a good idea about how it looked.

On the other hand, we still have only a dim idea about what strategies are the best ones. We've discovered a couple, like forking, but there are plenty that we have no clue about.

We know most of the rules of the game when it comes to fundamental physics, although we still have a few questions about issues that don't come up in our ordinary experience very often. And, when I use the term "modern physics" I'm really referring to new developments in fundamental theories of quantum mechanics, the standard model of particle physics and general relativity. But, clearly there are many "emergent physical phenomena" (by analogy, the strategy that flows from the basic rules), which we don't yet understand well.

Of course, studying emergent physical phenomena (which is not part of what I am calling "modern physics" in most cases) is easier when you know all of the relevant fundamental theories (and in many cases we know all of the relevant fundamental theories, even if we haven't mastered some that are irrelevant). Why? Because it allows you to rule out lots of oddball explainations for emergent physical phenomena and focus on the realm of the possible, instead. Someone trying to understand superconductivity doesn't have to spend a lot of time wondering how many atoms per gram of material are in a substance when formulating a model, or pursuing models where current propogates at faster than the speed of light. Likewise, our supercondictivity researcher can do back of napkin calculations to see if gravitational effects can be safely ignored in an experiment and be assured that this is sufficient due diligence on that front.

In other words, we are nowhere close to putting physicists out of work, even though we are quite close to being able to hand would be physicists a "rule book" that explains all of the laws of nature along with extensive annotations to show the precise experimental basis for each of them. It is a lot easier to fix a car if you have a book giving you detailed information on your particular model of car and all of its parts, than it is if you have to guess on points like what size piston was before it blew out.

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