One of the challenging topic to teach for non-science major students in oceanography class is tides. Although some students may have experiences of rising and falling of water level at the coast in the past, understanding the astronomical configuration, interactions of forces, and influence of the Coriolis force on the sloshing water movements can be over the top of their heads. Now that is just for the equilibrium tide theory and not even mentioning the harmonic analysis of tides. How can I explain the harmonic analysis of the tides with couple dozen components to this already overwhelmed students?
One year, I began to give them an example with tides of people – on our university campus – and let them have some sense how the scientists can decipher the fundamental forces intermingled in real ocean tides and essentially predict them. Even without any scientific training, all students know that there are surges and drains of people on campus and there seem to be some reasons for that. My analogy was to let the waxing and waning number of people on the streets on campus as ‘tides’ and think about what may determine those phenomena. Students started to come up with their reasoning. There are more people during daytime than nighttime. There are more people during weekdays than on weekend or holidays. There are more people during long semesters than during breaks. I began to add few more detailed twists: there are more people on the streets between quarter till the hour to the top of the hour even during the daytime on weekdays; there might be different surge of different groups on campus – staff may come early and leave early while students may come a bit later and leave later. By now, students show a sign of better understanding of what we are doing on their faces.
Many students nod their heads when I ask them if they can predict the level of surge of people on campus at any particular time, and if they can relate this to how we understand the ocean tides. Students may still forget all the gravity equations and configurations of the Sun, the Moon, and the Earth, but they would likely remember this analogy for longer period of time. A new way of thinking of and understanding the world by the students. I am grateful when I see this happen in the classroom.