What Does It Mean to “Make Sense” of Physics?

Abstract

What does it mean to “make sense” of physics? It’s not a simple question. Most people have an intuitive feeling for when things do (or do not) make sense to them. But putting this feeling into words—especially actionable words—is another task entirely. Generally speaking, there are two ways in which we commonly use the term “make sense.”1 The first connotes reasonability: for example, “it makes sense to start saving for college early.” Of the two, this is likely the more familiar meaning for the average physics teacher, since evaluating reasonability is a habit that we commonly teach in physics problem solving. We regularly instruct our students to check if their answers “make sense,” and there are numerous dependable strategies for this kind of evaluative sense-making such as unit checks, limiting-case analysis, order-of-magnitude estimation, and qualitatively examining relationships between variables.2 The second way we use “make sense” connotes understanding, intuition, and explainability (or lack thereof): for example, “it makes no sense to me how something as heavy as an airplane is able to fly.” This meaning is harder to put into action since it tends to be much more intuitive and emotional—what feels sensible to one person may be incoherent to someone else. I call this “intuitive sense-making,” to distinguish it from the evaluative sense-making described above. It is this meaning I would like to unpack here.