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Wednesday, September 29, 2010

seriously, completely understood

Sean presses forward with "Seriously, the Laws Underlying the Physics
of Everyday Life Really Are Completely Understood

I would put an emphasis on the word physics here. I think there's an
interesting question about the definition of physics. People who
think of themselves as physicists would of course like to define it so
that it is as powerful as possible. Reading Lubos a while back, (finally it got to be too much, and I found reading him, and the few attempts to engage with comments just too upsetting) one
could see this activity at play in the realm of string theory. String
theory was to be the best, most powerful theory out there. It didn't
matter that it wasn't well defined or maybe covered a variety of topics. Future work would go into its definition and elaboration. What was important was that it was known
ahead of time that it was all powerful.

Clearly the standard model and general relativity are powerful frameworks that are extremely fruitful for building models to describe and predict the world. And there do seem to be some facts about how we can take anything we find and break it apart and find the same underlying stuff. And if we put that stuff into an accelerator or in various
configurations, we can predict what it does.

But if the real point here is to emphasize the power and generality of the standard model and general relativity, then why talk about the "physics" of everyday life? This is the fundamentalism that Nancy Cartwright fights against. An effort to put disparate activities and types of argumentation together into one whole and say that it somehow covers everything.

Of course, I'm also sympathetic to this view of physics (or perhaps one can generalize to science, as well) as a unified extremely powerful discipline, and it was the faith that pulled me through graduate school. One thing for me that was discouraging (to continue a thread from Wimsatt's description of finding out how important "jerk" was) was when learning about quantum field theory and renormalization. QFT was presented as a generalization of the non-relativistic quantum mechanics we'd learned. But then it was shown that one actually got wrong answers and had to patch things up with this method called renormalization. If this was the fundamental theory, and it still required this much tinkering to get results for particle physics experiments, it seemed plausible that it might require different tinkering to apply it to correctly to limiting cases such as a helium atom. In some sense I hope I'm wrong about this, but it certainly was never presented in a coherent way. Foundations of QFT don't really seem to be too popular though, or seen as really open topics.

update... now the final (?) installment: one last stab.
I added a comment about how the reduction of helium to the standard model isn't usually done in a chemistry class, and it actually seems pretty hard. We're still trying to get protons out of QCD, with lattice QCD. I just wonder how much theories change as they pass from one discipline to another.

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