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Standard Model

The Theory of Almost Everything by Robert Oerter isn't sexy. The writing is workmanlike; the graphics are adequate. But the subject—quantum field theory and the "Standard Model" of modern physics—is arguably one of the most important developments of the twentieth century. Robin found the book remaindered at Borders last month, enjoyed it, and lent it to me. As I read it I realized that during my college years (the 1970s) there was actually a hurricane of discovery going on all around me in the high-energy theory side of the physics department, a turmoil that I never knew was happening. My part of the cosmos, gravity and astrophysics, sailed majestically along while the particle physicists fought just down the hall, quarks vs. Regge poles vs. electroweak theories vs. neutrino masses. Fascinating, to be in the midst of a decisive battle and not know it!

Oerter conveys that turmoil, though it's hard to know how much a non-physicist reader would sense. He does transmit some of the importance of the Standard Model via apt analogy, as in the Introduction when he compares physical theories with the operation of a computer:

... The computer is made of wires, integrated circuits, a power supply, and so forth. Fundamentally, all that is "really" happening in a computer is that little bunches of electrons are being shuffled around through those circuits. However, when your computer tells you "ERROR 1175: ILLEGAL OPERATION, APPLICATION WILL BE SHUT DOWN," it is not very useful to pull out the circuit diagram for your CPU. ... We can't locate "the operating system" or "program" on the circuit diagram—it is a higher level of description. Can we understand the error message by looking at the circuit diagram? No. Can we really understand the operation of the computer without understanding the circuits? No again. (Try building your own computer using only the Windows 2000 reference manual!) Both levels of description are necessary to "understand the computer," but the higher-level (operating system and program) functions can be explained in terms of the lower-level (circuitry) processes, and not the other way around. This is why we call the lower-level description the more fundamental one.

The Standard Model describes the "circuitry" of the universe. We can't understand everything in the universe using the Standard Model (even if we omit gravity), but we can't really understand anything at the most fundamental level without the Standard Model. ...

Oerter is excellent at describing how science, especially physics, actually works. In Chapter 3 ("The End of the World As We Know It") he discusses harmonic oscillators—systems that act like a playground swing, a car with bad shock absorbers, a vibrating violin string, a ripple on the surface of a pond, and so forth:

... It may seem surprising, but most of the problems you run into in physics are unsolvable. The mathematics is simply too hard. Progress is made by finding approximate problems that keep the important characteristics of the original problem, but which are solvable. Much of the time, the solvable problem that you end up with is the harmonic oscillator in some guise.

So what's the Standard Model all about? Briefly, it's an explicit set of rules to compute how the world works—that is, how the most fundamenatal subatomic particles interact with one another. The Standard Model is messy. It has 18 knobs that have to be set to particular values: masses of quarks, strengths of forces, etc. It offers no reason why those special numbers are the right ones. It can't handle gravity at all. But within its limitations, the Standard Model is extraordinarily accurate, a triumphant explanation of nature at a deep level.

Yeah, it's a bit messy. So is this book. Maybe that's just the way it has to be ...

(cf. No Concepts At All (2001-02-22), Nobel Neutrinos (2002-10-13), Key Problems (2003-10-11), ...) - ^z - 2008-09-06


(correlates: WhatPhysicsIs, BosonsAndFermions, NoProblem, ...)