Posts Tagged ‘heliocentric model’

Borneo Day 6: Wednesday, July 26

Physics class

The physics class at SMAN 1 Mandastana. I gave all the students a MAVEN postcard. I taught two astronomy activities on this day. The teacher is standing next to me with the NASA sticker.

Today Craig and I taught lessons in our subject areas. He taught the spaghetti tower engineering project and the DaVinci helicopter activity. I taught two astronomy lessons: the human orrery and the parallax activity.

Martapura River at dawn

The Martapura River at dawn, taken from the entrance to our hotel.

We had worked out what we would be teaching with the physics teacher the day before. When we first met the teachers on Monday, I noticed that she was the only female teacher not wearing a hijab, for whatever reason, and that she didn’t seem as carried away in the general hoopla about having us here. I could see that I needed to convince her that this would be a good experience for her students, so I asked Nazar if we could meet with her and discuss what we wanted to do. She warmed to the idea of teaching engineering and astronomy, and that we would trade off with another class so that both would get the lessons. We decided on the details and were good to go.

Laying down planets

Laying out the planet rings for the human orrery activity.

I set up in her classroom this morning, preparing the materials I had brought with me all the way from America in my blue suitcase. I had the string orbits and space probe for the orrery and the materials for making sextants. I also had my final presents for students, the remaining NASA stickers, postcards, and bookmarks. My suitcase will be much lighter after today.

As the first class started, I introduced the idea of the planets and how they were called the Wanderers by the Greeks. I asked them for the Indonesian words: Earth is Bumi and the other planets are essentially the same words as English and Latin. Then I asked for the name of the sun and this one surprised me: it is Mata Hari. I asked if it was the same name as the infamous World War I spy that lived in Paris, and they said yes. She was a Dutch woman who had lived in Indonesia with her husband and studied dance here when her marriage fell apart. She took the name of the Sun as her stage name.

Space ship arrives at Mars

The spaceship arrives at Mars after a six month journey. Now it has to wait there until Earth comes back around, and then a six month return voyage. We simulated all of this through our human orrery.

I described how Ptolemy worked out the motions of the solar system based on a geocentric model with deferent and epicycle circles like a spirograph. They understood the translations given by Nazar, but no one has seen a spirograph before. No matter. I plunged onward. I explained that Ptolemy had been brilliant but wrong, and that Arabic astronomers had gotten better observations and that Copernicus created a heliocentric model based on them. I certainly put Nazar to the test. I asked for volunteers to be the planets and Mata Hari, and then we went outside into the courtyard.

We laid out the string orbits in as circular a pattern as possible, then I ran the simulation calling out “Two weeks.” They certainly know what that means now. I pointed out how Mercury is fastest and Mars slowest. Then I showed how a space probe or human mission would take 6-8 months to reach Mars, starting when Earth is 90° from Mars and overtaking it, then arriving at Mars on the opposite side of the Sun. Astronauts would have to wait until Earth came back around to the same position before starting back, a 30 month round trip. At the end, I had students stand around the circles as zodiac constellations and demonstrated how retrograde motion works as Earth overtakes Mars.

Measuring stars

Students at SMAN 1 Mandastana measuring the angles from planets to stars in our parallax activity.

It was a hot activity out in the sun in the courtyard and we were all grateful to get back inside, even if the classroom isn’t air conditioned. I handed out Mars MAVEN postcards (I still had quite a stack) and the students insisted that I sign them as an autograph. That took a few minutes. Then we took photos again.

Mata Hari in 2010

Mata Hari in 2010. She was born from Dutch parents but moved with her husband to Indonesia, where she learned Javanese dancing. After divorcing and moving to France, she started a career as an exotic dancer and took her stage name from the Bahasa Indonesia word for sun, literally “eye in the sky.” She was accused of being a German spy and was executed in 1917 by the French.

After we traded classrooms, I was in a math teacher’s class and I taught a second astronomy lesson, this one a bit more challenging. This is the lesson I developed on how we calculate the distance to nearby stars using trigonometric parallax. I introduced the idea of using the tangent function to find the distance to the star based on the parallax angle created by the star’s apparent wiggling back and forth compared to the background stars because of the Earth’s revolution around the Sun. I had to ask the Indonesian word for star, which is bintang. There is a beer in Indonesia (popular on Bali but not so much elsewhere, because Muslims don’t drink alcohol) called Bintang or Star Beer.

Measuring stars 2

Helping students measure the angles to simulated stars in our parallax activity.

I divided the students into groups and handed out the wooden dowels, protractors, tape, string, and beads I had brought. The built the sextants, and then they drew up stars and planets on the cardstock with the markers I brought. Then we headed outside to the courtyard again. I used two meter sticks we had borrowed from the physics teacher (kept in the teacher’s lounge because they are very valuable and she doesn’t want them broken) and laid out and measured the planets on one line and the stars on another perpendicular line. I explained how to measure the angles with the sextants, and the math teacher helped her students figure out the process. The girls jumped in a lot more willingly than the boys (no surprise there), who were more willing to stand in as stars. Once we had at least two measurements from each planet to each star, even though not all groups had all measurements, we headed back inside as we were all getting heat stroke. I hadn’t thought of the problem with the heat, and the poor girls were roasting in their hijabs.

Measuring stars 3

Measuring the angles to stars from simulated planets using a sextant. It was a hot day, so once we got a few measures for each planet to each star, we headed back inside to do the calculations.

The students pulled out calculators (I hadn’t needed to bring the ones I had) and set to work on the tangent calculations once I had explained the formula. They seemed to all understand it, and had obviously worked with trig functions before. I drew up a table on the white board and we added their measurements, then their calculations. They results were exactly as expected, fitting the pattern much better than any class I’ve ever tried this with. The further out the planet, the better the results compared with the actual answers. The further out the star, the less accurate the results. We talked about why and how the tangent function reaches infinity the closer you get to 90°, so being off by even a degree for the further stars means great differences in the tangent function.

As you can imagine, this lesson took a bit longer than 90 minutes, but the teachers said to go ahead and continue because the students were really getting into it. I don’t know how many hands-on physics activities they normally do – I didn’t get to see the Fisika lab room or any equipment, but if they only have two worn out meter sticks, it can’t be that well equipped. Considering that astronomy isn’t regularly taught in high school, they seemed to have a pretty good grasp of basic astronomy, which leads me to think it is taught in junior high or elementary school. I saw some mechanical orreries in one of the elementary classrooms we visited in Jakarta, so it must be taught at some point.

Calculating answers

Students calculating the tangent function to find the distances to the simulated stars.

It was audacious of me to try to teach these lessons, which are hard to teach even in America. That they were so successful was beyond anything I could have hoped for. I saw some real comprehension in the students’ eyes; I actually taught them something new. I knew the language barrier would be a challenge, but Nazar’s English is good and we managed to communicate. It helped that I learned a few Indonesian words, enough to show my desire to reach them. The students reciprocated by listening and following instructions well, and they seemed to truly appreciate seeing how trigonometry really can be useful, or how simulations and kinesthetic activities can help to demonstrate science concepts.

Calculating star distances

Students calculating the distances to stars using the tangent function for the parallax activity. Their answers were the best I’ve ever seen in this activity, and showed the expected pattern that the more distant a planet, the more accurate the answer. The more distant the star, the less accurate the answer.

It also helped that science really is a universal language. Its concepts remain the same throughout the world; only the specific words change, but because many of them are based on Latin, they are fairly easy to understand and interpret across our two cultures. I have great gratitude to Nazar and the other English teacher for helping to translate the words, and to the science and math teachers for having already laid the foundation of math and science concepts. None of this would have worked otherwise.

Calculating star distances 2

Finding the distances to simulated stars using trigonometric parallax. These students at SMAN 1 Mandastana in Borneo did a great job with the parallax activity. It was a great honor to teach one of my own lesson plans here.

Craig’s engineering exercises also went well, although he did not see the level of creativity and divergent thinking one might expect of American students. Whether or not these types of activities will be used by the science teachers remains to be seen. One day of demonstration is not enough to overcome a lifetime of teaching habits. We won’t be here long enough to follow through, but at least we provided lessons that were unforgettable and truly lived up to our hype as master teachers.

Craig and David with teachers

Craig Hendrick and David Black with teachers at SMAN 1 Mandastana.

I don’t consider myself to be a great educator compared to many teachers I have met, but there are moments when I do well and this was one of them. As my message came through across barriers of culture and language, using concepts that are hard for even English native speakers to understand, I realized that I can be an excellent teacher, after all. We all rose to the challenge, partly because we dared to do what should have been impossible. At least at that moment, I felt deserving of the accolades and respect I have been shown here.

Physics class 2

The second class of the day. I did the parallax activity with them, and they did a fantastic job. I’ve decided that science is truly the universal language.


Read Full Post »