This essay originally appeared on a listserv archived at Boise State: PHYSLRNR - PHYSICS LEARNING RESEARCH LIST on April 3 2003. This version has been slightly edited.
First Person Physics
I would offer that physical sciences curricula should explore multiple starting points, and one of these should be the human body, which we presume each student has. This would be in contrast to the kinematics/ mechanics approach which focuses on pulleys and levers, but doesn't spontaneously evoke a sense of doing work oneself. One observes. Typical kinematics is one step removed from personal experience.
In the body-centric approach, one spends time on the concept of energy as measured in calories and joules. Some students may not realize that food labels outside the USA often express the energy values of various foods in terms of kilo-joules, not calories (which are really kilo-calories). This idea of taking in energy sources (foods) and expending them through exertion, brings physics back to the first person. We might call this "first person physics" or "I-tense kinematics".
Consequent to this focus is the need to replace "horsepower" with something closer to home. The idea of "power" (energy per time) might be given a joules/second constant calibrated to the average adult human, as many students today have little experience with large draft horses (or horses of any kind) except through Budweiser commercials and the like.
One author I'm aware of who takes this approach is Buckminster Fuller, writing for Fortune back in the depression era. He wrote about "energy slaves per capita" as a critical measure, where an "energy slave" does work (expends energy) at the rate typical of an adult human -- but here we're talking about inanimate power sources, such as the electrical utilities. That meter on your house might be calibrated in "energy slave" equivalents.
I think there's lingering prejudice against beginning with the human body given it's a complex system, whereas physics-the-discipline has historical roots in machine engineering (with steam powered engines replacing horses). Historically, the human body was the province of medical science and biology. However, now that we have a pretty clear atomic model and understand how energy is stored and released by means of chemical reactions, I think an approach to atomic theory through a streamlined tour of biochemistry makes a lot of sense.
At the risk of indulging in stereotypes, I'm going to hazard that more women could be retained in physics if this more anthrocentric approach were to supplant the steam engine approach. There'd be a lot more integration of physics (as the study of energy transformations) with physical education (the gymnasium), wherein kilo-calories get expended, and wherein nutrition makes a difference.
Please note that I'm only talking about a starting point -- the math revolves around conversion constants and the ideas of energy, work and power, while the relevant experiences are first person, related to eating and exertion. Once we're well into the web of concepts, then it's fine to go off in the direction of steam engines, and photo-voltaic cells. But we'd keep coming back to the body. For example, when venturing into electricity, it'd be the bioelectronic mechanisms that we might study first -- how charge is propagated along a neuron by means of ionic chemical reactions. Too bad if that's the province of biologists; it's physics just as well.
Note also that I'm talking about the physical sciences, not just physics per se. The syllabus for such an intro course might include 'Uncle Tungsten: Memories of a Chemical Boyhood'. However, I'm also suggesting that this approach be explored for physics per se, i.e. once we've used the human body for an entry point into the whole realm, we should go back to it when starting with physics in particular. Just an idea -- one approach among many, but perhaps insufficiently explored.