Physics with Illustrative Examples from Medicine and Biology Volume 1: Mechanics. , George B. Benedek and Felix M. H. Villars AIP Press/Springer-Verlag, New York, 2000 [1973] 2nd ed. $69.95 (548 pp.). ISBN 0-387-98769-X
Physics with Illustrative Examples from Medicine and Biology Volume 2: Statistical Physics . AIP Press/Springer-Verlag, New York, 2000 [1974] 2nd ed. $69.95 (640 pp.). ISBN 0-387-98754-1
Physics with Illustrative Examples from Medicine and Biology Volume 3: Electricity and Magnetism . AIP Press/Springer-Verlag, New York, 2000 [1979] 2nd ed. $69.95 (670 pp.). ISBN 0-387-98770-3
Physics with Illustrative Examples from Medicine and Biology Volumes 1–3: $169.00 set ISBN 0-387-98952-8
The physics department at the Massachusetts Institute of Technology began about 30 years ago to offer a special calculus-based introductory course for freshmen and sophomores interested in biology. This led to the first edition of George B. Benedek and Felix M. H. Villars’s Physics with Illustrative Examples from Medicine and Biology. The book was issued by Addison-Wesley in 1979 as three paperback, typescript volumes. The books fascinated many physicists with the application of physics to problems in biochemistry and physiology, but they have been out of print since 1990. Now that AIP Press and Springer-Verlag have issued a second edition, as printed volumes, a new generation of physicists can learn from them.
The content is unusual for an introductory physics course. Many of the topics are traditionally considered to be physical chemistry, biochemistry, or physiology. However, physicists usually approach them from a slightly different point of view; physics should reclaim them as its own.
In the mechanics volume there are three topics that I found particularly fascinating. One is the physiologic effects of altitude sickness. The book describes an ascent of Mont Blanc in 1869 and a tragic balloon flight in 1875. Both are explained by combining the decrease with altitude in oxygen partial pressure with some simple observations from pulmonary physiology and the empirical oxygen dissociation curve for hemoglobin. The second topic is surviving a fall from a great height. Survival can be related to the distance traveled and duration of the decelerating impact. A number of amazing survivals in falls from aircraft are documented. There is also a discussion of feedback systems not usually found in an introductory text. It begins with the variations in speed of a steam engine under load, shows that these variations can be reduced with the centrifugal governor, and goes on to describe the instability that results from the introduction of a time delay in the feedback system. Biological examples include regulation of body temperature and blood glucose.
Some of the topics in the statistical-physics volume are quite important in physiology, but are usually ignored by physicists. Two examples are diffusion, which is important for transport at the cellular level, and the flow of solute and solvent across a membrane, effected by a combination of drift and diffusion.
Many other examples, such as the chemical potential, entropy of mixing, and Helmholtz and Gibbs free energies, are normally found in physical chemistry or biochemistry courses. Here we see how we can teach them from a physics perspective. Particularly fascinating is the Luria–Delbrück experiment, a classic in bacterial genetics. When E. coli bacteria are infected by a bacteriophage virus, some of them survive and reproduce, and their descendants inherit resistance. The experiment, reported in 1943, showed conclusively that resistance in descendants does not obey simple Poisson statistics but is due to mutations—a wonderful example of quantitative analysis in genetics.
The volume on electricity and magnetism is novel. Coulomb’s law is introduced as the force between an atomic nucleus and an electron, rather than as a force between macroscopic charged objects. The discussion of field lines is more thorough than usual. The Laplace equation is derived and a “stockpile” of solutions is presented for later use. There is an extensive discussion of polarization and dielectrics, including gases and nonpolar and polar liquids. Electrocardiography is explained using a dipole model. Unusual in a physics text, but important for biology, are the Nernst–Planck equation, Debye shielding, Poisson–Boltzmann equation, electrophoresis, electrochemistry, Debye–Hückel theory, and Donnan equilibrium, all of which lead to the cable model of the axon and the Hodgkin–Huxley model for the action potential. The last chapter, on electromagnetism, is a standard but compact introduction to magnetism, Maxwell’s equations, and electromagnetic waves.
Some differences exist between the first and second editions, but not as many as one might expect. In the section on feedback systems, I wish that the authors had added something about our current understanding of chaotic behavior in nonlinear systems. The most extensive changes are in volume 2, in which a section has been added on the Monod-Wyman-Changeaux allosteric model for oxygen binding to hemoglobin and on other models for ligand binding to proteins. I was disappointed to find that, in volume 3, the magnetic field associated with the heart was not described. There are interesting similarities between the electrocardiogram and the magnetocardiogram, both of which arise from the current dipole associated with cardiac activity. I also did not find mention of the importance of gated channels that we now know lead to changing sodium and potassium conductances of the Hodgkin–Huxley model.
This is not your typical introductory text, in terms of format and style as well as content. The writing is compact. It has none of the color drawings and photographs that take up so much space in current introductory texts. Vector differential and integral calculus are used extensively. The text discusses solutions of the Laplace equation with various boundary conditions. A teacher will have to examine it carefully and decide whether to use it as the only text or as a supplementary text in an introductory course.
These are classic books, and anyone planning to include biophysical examples in a calculus-level course should study them carefully. The authors are to be congratulated for their work, and I commend AIP Press and Springer-Verlag for making the books available again.
Russell Hobbie is professor emeritus of physics at the University of Minnesota in Minneapolis. He has done research in laboratory medicine and radiological physics.
