|Author||Frank Firk||Entered||2000-12-24 13:16:51 by bcrowell|
|Edit||edit data record||Freedom||Public domain (disclaimer)|
|Subject||Q.C - Physics|
|Fails to connect with reality and experiments|
by Ben Crowell (crowell09 at stopspam.lightandmatter.com (change 09 to current year)) on 2000-12-24 17:10:12, review #42
The choice and order of topics is unusual:
Although in some ways this book seems intended to be the hardest introductory physics text ever written, it should be noted that Dr. Firk covered this material at the rate of only one chapter every two weeks. Also, many of the homework problems are fairly straightforward.
The first chapter is likely to be a big barrier to entry, even for the best prepared and most highly motivated students. Differential geometry comes on page 5 (!), and vector calculus is introduced via quaternions, for reasons that were unclear to me. This chapter exemplifies my main complaint about the book, which is that new mathematics is introduced without sufficient physical motivation, and often without much mathematical motivation either.
Another example of this tendency is the introduction of the Lorentz transformation in ch. 3. The perfectly straightforward approach to its introduction, used in every other book I've ever seen, is to start from the constancy of the speed of light and derive the Lorentz transformation. Firk, however, chooses a strange procedure based on the expectation that space and time will be treated symmetrically. After some less than convincing manipulations, he displays the Lorentz transformation, and then points out that "the difference of squares is an invariant: (ct)2 – x2 = (ct')2 – x'2." The connection of this fact to the constancy of the speed of light is not made clear. No experimental evidence for or tests of relativity are discussed (except for a single phrase referring to the Michelson-Morley experiment, which assumes that the student already knows what it is).
In fact, the whole book is so lacking in discussion of experiments and real-life applications that it tends to a kind of navel-gazing platonism. Other problematic points include a claimed proof of conservation of angular momentum based on Newton's laws (which fails because it assumes center-to-center forces) and the introduction of mass-energy equivalence and relativistic dynamics simply by the assumption that momentum must be a four-vector.
Although there's nothing wrong with creating an introductory physics text aimed at the very best students, I can't recommend this book for that purpose. The Berkeley physics series would be more appropriate.
I should mention that I knew Dr. Firk, although not well, when I was a graduate student at Yale.
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|Inspiring lecture notes -- not to be read in isolation|
by David S. Rosenberg (drosen at stat dott berkeley ddot edu) on 2004-04-06 02:48:43, review #396
During the fall semester, we were expected to read the first half of the excellent book Introduction to Special Relativity, by Rindler, to supplement the lectures. We also had French's Special Relativity for an easier introduction. When Firk takes an unusual approach to a topic, it should be understood that we were also learning the more traditional approaches from other sources.
I remember my own initial disappointment in the particular case that the reviewer cites, when Firk motivates the Lorentz transformation by saying that space and time should be treated symmetrically. It seemed as though we were developing Physics by leaps of faith. However, I eventually came to see this type of argument as the good stuff in the course. Anyone can present the standard set of mathematical axioms and definitions underlying relativity, or any other field, and derive the important results of the theory. What Firk gives us is the idea that there is some rationale behind the development of the axioms that goes beyond simply searching for the laws that happen to agree very closely with experimental results. He presents the ideas of symmetry and invariance as meta-principles of Physics -- ideas that should be looked to for guidance in developing new theories. I found this quite exciting.
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