…….and other fun meteorology demos
Lately, I have performed a number of demos in my classroom that I think worked out very well. I’ve been lucky to teach meteorology twice and therefore perfect my craft. And by “perfect” I mean “improve”. There is a certain degree of comfort in knowing that I can learn from my mistakes and grow as a teacher, and I have loved teaching some of the same lessons twice! My CT said that it is the best unit I’ve taught. I think so, too. These are some of the demos:
Crushing cans to teach about how temperature affects pressure
You can find a million Youtube videos about this, and they are what I used in my last placement, rather than risking trying it myself. This time, I got braver, and I did it myself, which was much more engaging for the students. A Youtube video with a gigantic barrel would have been a nice addition, though, had we had all the time in the world.
I put a little water in an empty soda can and put it directly on a hot plate until you could see steam coming out of the top (it didn’t work when indirectly on the hot plate in a pot of water). It worked better when I let the water in the can boil for 10 or so minutes. I told the students that I was going to then put the can into ice water (cold tap water from our classroom faucet actually did work), and asked them what they thought was going to happen. They enthusiastically yelled out answers. I would say that just about every student was engaged.
I used tongs to pick up the hot can, quickly invert it, and put it into the cold water. It crushed because of the pressure change, and even made a loud popping noise in a few classes. This seemed to really work in allowing the students to connect the uneven heating of the Earth with changes in pressure, which led us into weather.
In other news, Sol Burrito sells canned soda, should you also not drink any, and the night before I ordered many for delivery. Ha.
Cloud in a Bottle
My cohort saw Mike demonstrate this one, and I stole the idea, though it is harder than it looks. Put a little rubbing alcohol into an empty plastic water bottle. It did not work when I tried a soda bottle, I think because the plastic was too thick! Close the bottle and twist it tightly. This actually takes a lot more strength than Mike made it appear to. Show the students that you are working hard to twist it, and ask them if you are currently putting high or low pressure on the bottle. Then let go, and, as the pressure gets low, a cloud forms. The more you twist the bottle, until it feels like its about to burst in your hands, the better the cloud.
This demo seemed to work well, was quick and easy, and was something students enjoyed doing. The bottle was brought up again on many occasions, and often passed around the room. I put tape over the top of the bottle so that no one would attempt to drink it, thinking that it was water. I’ll do this demo again!
Paper roll pressure columns
I did this demo at my last placement, and improved it for this placement so that it went more smoothly. I taped 6ish pieces of construction paper of various colors together, forming a long column, which I rolled up. I then asked for 4 volunteers for my human model, and always had plenty more than 4.
I asked which 2 of the 4 felt that they could stand on a classroom counter top safely, and consciously picked 2 who I knew could. They climbed onto the counter-top (we have a nice low, safe one. I did this with chairs at my last placement because we didn’t.) Each of the 2 was handed a construction paper roll.
I asked one of the other 2 to sit on a desk and one on a chair. Another method is to choose a very tall student and a very short student (by asking “Who here thinks that he/she is tall?” rather than classifying students by height myself.) The point is to have two sitting students in front of the two students on the counter whose heads are at noticeably different heights.
I asked each of the 2 standing students to unroll their pressure columns, holding them at equal heights (in my original demo at my last placement I used a meter stick labeled ‘top of the atmosphere’ to designate this height, but it became a weapon so I decided against it this time; also 4 students are easier to manage than 6.) The two sitting students were to hold their pressure columns against their foreheads, forming a visual and colorful column of pressure over each of their heads, with the taller column over the lower/shorter student.
I told the students that these columns represent the atmosphere over our heads (they had already done their atmosphere foldables about the layers of the atmosphere.) I asked which layer the bottom piece of construction paper represented, the troposphere. I then asked which student had a taller column over his/her head, and why. This was the shorter student. I then said that that student was in Rochester, at low altitude. The other student, meanwhile, climbed Desk Mountain. The student who was higher up had less pressure over his/her head. A very tall student then responded ‘So I have less pressure over my head than you all?’ which I loved. It was just a perfect moment! I bet him saying that will help everyone in his class remember it!
This demo seemed to work. Kids remembered it. One catch though, was that, when I later tested kids about what kind of weather low and high pressure systems bring, many thought that low pressure meant cold weather and high pressure meant hot weather despite me knowing that that was a common misconception (thank you, first placement!) and reiterating it 1000 times. One student in particular said ‘Low pressure means cold because when you are up on a mountain its cold like those snow capped mountains and the pressure is less there.’ Crap. Did my demo cause this misconception? What do you think?
Mission for next week: Why do they still think that low pressure means cold? I think I’m gonna ask a few students.
Flashlight on the Earth
This was a station, in which I wanted my learners to see that the sun hits the equator more directly than it hits Rochester. I have not perfected this one yet.
I had learners shine a flashlight on a location on the equator, and measure the diameter of the circle the flashlight beam made using string. This was difficult for students, as they didn’t often understand how to use string to get a distance, then put the string against a ruler. I then had them keep the flashlight where it was, and tilt it towards Rochester, measuring that circle. The point was that the circle was now bigger, hitting Rochester at more of an angle.
It is very important to get a flashlight that emits a small circular beam. I did not have the ideal flashlight for this. Despite this, most learners got the point I wanted them to get, so I’ll do this activity again, with some changes. It was hard for learners to hold the light at the same exact height. I should have had them put it on a counter top or table or some set place.
I’m open to more ideas and suggestions!