Learning Critical Thinking Through Astronomy, Week 10Posted: October 24, 2016
This week was all about observing. Students were assigned Activity0301, which consists of two main parts. The activity, both parts, is to be done from the same location each night. Students are expected to have previously established the four cardinal directions at their respective observing sites.
The first part is observing Moon. This can be simple, or it can be not simple and I designed this part of the activity with both simplicity and subtlety in mind. The main idea is to go out AT THE SAME TIME ON FIVE SUCCESSIVE EVENINGS and look for Moon in the sky. If it’s visible, draw its visual appearance and record the date, time, and general sky conditions. When I introduced the activity in class, I pointed out that choosing a time during daylight is perfectly legitimate. This, of course, generated many surprised stares because “everybody knows” Moon is never visible during daylight. It’s astounding how widespread this misconception is despite it being trivially contradicted. The catch is that where we are in the synodic cycle (phase cycle) determines whether Moon is visible during daylight or not. Each student can pick his/her own time for going outside. (I’ve considered assigning each student a pareticular time to go outside, but I don’t think I could get by with that given their varied work schedules and other external obligations. There’s already too much resistance to doing anything outside of class so I dare not assign specific times for things.) If enough people go out at different times, we can come back to class next week and piece together a timeline for when Moon was visible (and more educationally, when it was NOT visible!) and its corresponding visual appearance. The timing of this activity this semester was excellent because it formally began near full Moon so Moon would be visible all night, which means students could go outside before or after midnight and “find” it. More than likely, most student will try to go outside between sunset and midnight rationalizing that they can’t get up early to go out between midnight and sunrise (but they can certainly do other things between midnight and sunrise, things more important than their education). If they go outside at the same time between sunset and midnight, they will eventually not be able to find Moon and I’ve told them that not finding it counts as data. Remember that at this point, they know nothing about what terms like “full Moon” mean. They’re simply being asked to make observations and record those observations. As usual, they strongly resist, but I point out that this is the type of thing they were previously complaining about NOT doing earlier in the course.
The second part of the activity consists of observing four stars close to the horizon, one in each of the four cardinal directions, for thirty minutes each. For each case, draw a simple diagram consisting of the horizion, a small vertical tick mark on the horizon labeled with the direction the diagram faces, a representative star close to the horizon, and an arrow showing the star’s approximate motion from the beginning to the end of the thirty minute observation.
The total minimum time committement for this activity is thirty minutes for each of the four stars, five lunar observations each of which takes only as much time as needed to look for and find (or not) Moon and draw it on a blank template I provide to them. Then add in the time necessary to record most of their work (sans drawings) in WebAassign. I estimate two and a half to three hours max. As you see when I reveal the results next week, based on previous years most student will not even attempt the activity. I hope I’m wrong this time, but I have yet to see more than about 25% participation.
In class this week, we focused on a WebAssign assignment that reinforces modeling shadow behavior with the celestial spheres. Ironically, one student walked in Friday morning asking for help in assembling the sphere, which we had already done over a week ago. This is what I’m up against.
As always, feedback is welcome.