 |
Asia-Pacific Forum
on Science Learning and Teaching, Volume 12, Issue 1, Article 10
(Jun., 2011) |
In sum, these four examples are aimed to illustrate the limitations/restrictions of popular theories and to highlight the functions/values of less intuitive concepts. For example, “thermal expansion” entails chemical bonds, which are limited to solids or liquids (#1), but inapplicable to ideal gas (#2). However, the state function of the ideal-gas law itself is insufficient to explain many real-life examples, e.g., adiabatic processes. Thereafter, the rather abstract principle of the 1st law is initiated and reviewed (#3 & #4).
The four examples are not novel, but were modified from the existing teaching resources (e.g., Walker, 1977) to enhance their pedagogical functions, including four features. 1. To improve visibility by assembling demonstrations (#1) or supplementing photos (#3) of existing conceptual questions. 2. To address students’ prevalent pitfalls, e.g., highlighting the limitation of thermal expansion (#2) and the ideal-gas law (#3 & #4). 3. To bridge related principles, e.g., integrating the 1st law and kinetic theory (ΔU=ΔEk∝ΔT, in #3 & #4). 4. To increase the sophistication of the scientific reasoning in order to improve students’ intellectual satisfaction (Viennot, 2006), e.g., why the tapered shape at the top of the lamp allows the lava to sink (#1), and specifying the causality of “work alters temperature” (W→ΔU→ΔT) in adiabatic examples (#3 & #4).
The four examples were adopted in the author’s introductory physics classes via various teaching activities. Example 1 was introduced along with a worksheet and Leif’s article, becoming an open-form assignment. By means of a whole-class dialogue, Example 2 and Example 3 served as “appetizers” for initiating new topics, and Example 4 reviewed the First Law after the completion of teaching the topic.
By means of discussing these real-life examples, the “cold” physics theories can become sensible and relevant to daily life experiences. The functions, limitations, and relations of the physics theories are clarified and practiced repeatedly (Buncick, Betts and Horgan, 2001; Chang, 2011). Therefore, learning physics becomes more meaningful, sophisticated and heuristic.
