Guest post: Getting the Physics Right

Today we feature a guest blog from author Martin Krieger about his book Doing Physics.

When I am writing I always have one of my teachers in the back of my mind. My worry will be that they will find out that what I am saying is wrong, or that I made a mistake. Now if this were a matter of mathematical or physics reasoning that would concern me much less than when I am trying to convey in everyday terms: what the physics is about. So if I am analogizing the theory's division between particles and fields and their interaction, the analogy being to Adam Smith’s pin factory where there is a division of labor, I have not only to worry about the quantum field theorists but also the economists. When I am analogizing particle interaction to the rules of kinship and marriage, there is the theoretical particle physicist and the anthropologist of kinship who is looking over my shoulder. Doing Physics is meant to be read by high school students on, and I surely don’t want to spread nonsense. And I don’t want to be unfaithful to the science.
 
On the other hand, my subsequent books Constitutions of Matter (Chicago, 1996) and Doing Mathematics (World Scientific, 2003), try to make sense of highly technical work in mathematical physics and mathematics, itself. My nightmare would be that specialists would find my account flawed, a mistaken interpretation. I don’t expect them to think any of this is physics; rather it is about how work is done, and it had better be true to life. In Doing Mathematics I discern an analogy between an analogy in physics and one in mathematics. Such an analogy of analogies is called a syzygy. The mathematicians have been working in this realm for 150 years, while the physicists are rather latecomers. On the other hand, the physicists have a very clear example of the analogy. I was enormously relieved when one of the experts in the mathematics seemed to have liked my discussion and not found it too wanting.
 
Why do this sort of book writing? I am not doing a popularization, and my book is not a gee-whiz account. Rather it is an entrée into an esoteric world, much as one might want an everyday account of a sacred text of antiquity. This is what is going on here. These are the moves being made. This is how these people think. This is what they have in mind. This is how the physics is part of the everyday culture you know already. In the case of the more technical books, the idea is to point to the motivating themes and ideas, themes and ideas that are not so technical in fact.
 
I have one other big goal. I want people to appreciate the physicist’s account of the natural world, how that account is not beyond them. In the 20th century physicists discovered why the sun shines, and they have the most powerful account of creation since Genesis. Just as the first six days of Genesis is also an account of the rules of the Hebrews’ world, so the physicist’s account of the origin of the universe is also an account of the rules of the physical world.
 
What’s strange to me is that all popular writing about physics and mathematics is in baby terms. Yet in fact a cultured person might be able to see why physicists do what they do and how they account for the world, and what mathematicians do and how they describe the structure of their abstract world. Yes, it’s not the same as a PhD in these fields, but it is possible to get close to what is going on. At least as close as it is possible to understand another culture without being of that culture.

Martin Krieger is Professor of Planning in the Sol Price School of Public Policy at the University of Southern California and a Fellow of the American Physical Society. He has taught at Berkeley, Minnesota, MIT, and Michigan and has served for many years on university promotion and tenure committees. The second edition of his book Doing Physics was released this month.