Thermodynamics and the underlying statistical picture of random molecular motions are fundamental in biology. In order to make sense of processes ranging from respiration and photosynthesis in the cell to the survival and stabilization of ecosystems students need a good understanding of energy, its conservation, its availability, and its transformation. Since biology is about the generation, maintenance, and evolution of organization and structure, the concept of information and its statistical mechanical partner, entropy, is critical. Students typically encounter energy, enthalpy, and entropy in introductory biology, chemistry, and physics classes. But the approach taken in the three disciplines can be dramatically different. Often, they make different (unstated) assumptions resulting in statements of the laws of thermodynamics that look different in different classes. This lack of consistency raises barriers to students' development of a coherent understanding of these important ideas.
In this project, we work with an interdisciplinary group of physicists, chemists, and biologists at four universities to (1) come to an agreement on a common content and representational scheme; (2) create a literature survey bringing together results about student understanding of concepts in thermodynamics from chemistry, biology, and physics education research; (3) study student understandings of and attitudes about the basic concepts of energy, entropy, diffusion, and stochastic processes; (4) create web materials including text and materials for active-learning instruction for use in an introductory physics course for biologists; and (5) create and validate an instrument to evaluate students' learning gains on these topics.
This project developed an innovative introductory physics curriculum for life science students (students majoring in life science areas such as biology, biochemistry, and neuroscience, as well as pre-medical students) and evaluated its effectiveness at enabling students to recognize the value of physics in understanding the life sciences, as well as to use the tools of physics to address life science and medical questions. In particular, this curriculum foregrounds the importance of thermodynamic and statistical phenomena — physical phenomena which involve extremely large numbers of atoms or molecules undergoing random behavior at the microscopic level, but which have predictable outcomes at the level of the entire group, corresponding to well-defined macroscopic properties. (For example, the temperature of the air in a room involves the random motion of the air molecules, so the microscopic motion of any particular air molecule is not known, but the corresponding temperature, a macroscopic property of all of the air in the room, is very well known.) These phenomena are essential to the workings of molecular biology and biochemistry. Such phenomena are commonly taught to a limited extent in chemistry and in traditional introductory physics courses, but in a manner that focuses on the macroscopic properties with little attention to how these arise from microscopic dynamics. In addition, chemistry and physics commonly differ in the terminology and mathematics used to describe these phenomena, which can confuse students significantly and make it less likely that students will make connections between what they learn in physics and what they learn in chemistry. This leaves students ill-equipped to apply these very important concepts in the life sciences and medicine. This project developed an approach to teaching these topics that helps students understand the microscopic basis for these traditionally difficult topics and use what they learn in physics to better understand what they learn in chemistry and biology. The development process began by examining the findings of physics and chemistry education research for teaching these topics. These findings were used to inform developing the new curriculum. The success of the new curricular materials was assessed and the assessment results were used to further improve the curriculum. The University of Maryland was the primary developer and evaluator of this curriculum. They have observed that students from the course that piloted this curriculum have gained understanding of the concepts; in addition, the students gained the ability to recognize the usefulness of using physics to understand the life sciences. At Swarthmore College, to date only the semester covering optics, electricity, and magnetism (the second semester of introductory physics), has been optimized for life science students. An optimized version of the first semester of introductory physics will be offered beginning in Fall 2015. Most of the thermodynamic and statistical physics phenomena appear in the first semester, and will be incorporated as part of that new course. For this project, Catherine Crouch developed materials on statistical phenomena in the electricity unit and provided feedback on the approaches and materials for the other topics developed at Maryland. She also began preparing to adapt and use elements of this curriculum herself, including collecting assessment data in the non-reformed course for comparing to the future offering of the reformed curriculum at Swarthmore. This project met the NSFâ€™s Merit Criteria of advancing basic knowledge and having the potential to benefit society by adding to the knowledge of how to teach this material well to life science and pre-medical students, as well as contributing to the curricular resources for doing so. It has been well known that these are difficult topics for students to understand, and by supporting students in learning these well, this project improved the preparation available for future research scientists and physicians, which has the potential to improve their professional work.