Reinventing Physics For Life-Science Majors

The July issue of Physics Today contained an article by Dawn Meredith and Joe Redish titled “Reinventing Physics for Life-Science Majors.” Much in the article is relevant to the 4th edition of Intermediate Physics for Medicine and Biology. The main difference between the goals of their article and IPMB is that they discuss the introductory physics course, whereas Russ Hobbie and I wrote an intermediate-level text. Nevertheless, many of the aims remain the same. Meredith and Redish begin

Physics departments have long been providing service courses for premedical students and biology majors. But in the past few decades, the life sciences have grown explosively as new techniques, new instruments, and a growing understanding of biological mechanisms have enabled biologists to better understand the physiochemical processes of life at all scales, from the molecular to the ecological. Quantitative measurements and modeling are emerging as key biological tools. As a result, biologists are demanding more effective and relevant undergraduate service classes in math, chemistry, and physics to help prepare students for the new, more quantitative life sciences.

Their section on what skills should students learn reads like a list of goals for IPMB:

• Drawing inferences from equations…. 
• Building simple quantitative models…. 
• Connecting equations to physical meaning…. 
• Integrating multiple representations…. 
• Understanding the implications of scaling and functional dependence…. 
• Estimating….”

Meredith and Redish realize the importance of developing appropriate homework problems for life-science students, which is something Russ and I have spent an enormous amount of time on when revising IPMB. “We have spent a good deal of time in conversation with our biology colleagues and have created problems of relevance to them that are also doable by students in an introductory biology course.” They then offer a delightful problem about calculating how big a worm can grow (see their Box 4). They also include a photo of a “spherical cow”; you need to see it to understand. And they propose the Gauss gun (see a video here) as a model for exothermic reactions. They conclude

Teaching physics to biology students requires far more than watering down a course for engineers and adding in a few superficial biological applications. What is needed is for physicists to work closely with biologists to learn not only what physics topics and habits of mind are useful to biologists but also how the biologist’s work is fundamentally different from ours and how to bridge that gap. The problem is one of pedagogy, not just biology or physics, and solving it is essential to designing an IPLS [Introductory Physics for the Life Sciences] course that satisfies instructors and students in both disciplines.