May 7, 2012
For every action there is an equal and opposite reaction.
– Newton’s Third Law of Motion
I introduced my Middle Schoolers to the principles of Newton’s Laws of Motion last week.
The discussion started off with projectiles. If you’re floating in space — zero gravity — and throw something, like a basketball, away from you, you’ll be pushed off in the opposite direction. In fact, if you throw something that has the exact same mass as you do away from yourself, you’ll move off in the opposite direction with the exact same speed as the thing you threw.
Then I brought up rockets, and how they’re expelling gas to move them forward. I think it was the phrase, “expelling gas” that did it. The next question, which the student brought up somewhat circumspectly, sidling around the issue and the language, was (more or less), “So if you expel gas in space will you move off in the other direction?”
The simple answer, appropriate to that stage of the discussion, was, of course, “Yes.”
Which lead to to, “What about spitting?”
“Yes.”
“What about, you know, peeing?”
“Yes, except …”
At that point I thought it would be wise to rein it in a little, and make a further point about the whole action-reaction thing.
“You see, if you expel anything, wouldn’t it just be stuck in your spacesuit with you? Then you’re not really expelling it, it’s still attached to you, so you wouldn’t really move. What would be more useful would be to collect it in something like a spray can or a squeeze bottle. Then you can just squirt it out opposite the direction you want to go in to control your movement.”
This produced a moment of thoughtful silence as they figured out the logistics.
Notes
I thought this was a useful conversation to have. The students were interested and animated. And I believe it’ll be memorable too.
An artist's concept depicts the Deep Space 1 probe with its ion engine operating at full thrust. Image via NASA.
P.S.: I’d wanted to talk about ion drives, which operate on the same reaction principle, but are much cooler (after all they’re used in Star Trek). Instead of burning fuel to create the propulsive force ion drives generate an electric field that ejects charged particles; we’d been talking about ions and charged particles earlier in the day. However, I decided on the day that it would just complicate what was a new issue. I’ll probably bring it up this week though as we recurse through Newton’s Laws.
Citing this post: Urbano, L., 2012. Flatulence ... in Space, Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in Natural World, PhysicsNo Comments » - Tags: journal, middle school science, physics
April 27, 2012
The grill entering the final stages of construction by Ryan V. and Robert M.. Photograph by Autumn F.
It took us a little more than half a day to build a grill. It’s a simple thing of cinder blocks and sand, located near the soccer field so it’ll be convenient for bbq’s next year.
It took the highschoolers all morning to dig an outline for the base of the grill and lay in the foundation, despite it being a small, three-quarters of a rectangle shape, and only ten centimeters (4 inches) deep at maximum. The local clay is extremely dense and hard.
The foundations took the longest time to build.
But the foundations were firm, secure, and level.
When the base was done, two middle-schoolers — ably documented by a peer photographer — finished all the visible parts of the structure in just half an hour.
The next day, after I’d given them a presentation on cognitive development during the teenage years that I realized how nice a metaphor the grill construction was for the training of the brain during adolescence. The extensive pruning and myelination that typifies adolescence establish neural pathways are the foundation for future mental growth.
Good, strong, level foundations are the basis for a rich and fulfilling life.
Good foundations require some effort, but they're worth it.
Citing this post: Urbano, L., 2012. Building a Metaphor (Actually a Grill), Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in Classroom Notes, PedagogyNo Comments » - Tags: adolescent development, cognitive development, construction project, journal, Pedagogy
January 25, 2012
Moving the magnet through a wire coil creates an electric current in the wire. Animation captured from the VPython program: Magnetic Induction - Coils.
My students asked me this question the other day, and while slapping together an animation of electromagnetic induction I gave it some thought.
This program itself is really simple. It took about 15 minutes.
But that’s not counting the half hour I spent searching the web for an image I could use to illustrate magnetic induction and not finding one I could use.
Nor does it count the four hours I spent after I got the animation working to get the program to take screen captures automatically. Of course, I must admit that figuring out the screen captures would have gone a lot quicker if I’d not had to rebuild all my permissions on my hard drive (I’d recently reformatted it), and reinstall ImageMagick and gifsicle to take the screen captures and make animations.
Citing this post: Urbano, L., 2012. How Long does it Take to Make a Vpython Program?, Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in ProgrammingNo Comments » - Tags: journal, physics, programming, programming with VPython, vpython
December 29, 2011
Impromptu concert. The choir practices in the keeping room.
Although we’re not precisely sure why, the choir was quite the popular choice this year. The students are enthusiastic, and our music teacher, Mr. E., does an awesome job. It’s really nice to run into them practicing in the commons.
In this case they were in the Keeping Room — long, vaulted ceiling, remarkable acoustics. They practiced at one end; people accumulated at the other.
Citing this post: Urbano, L., 2011. The Keeping Room, Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in VignettesNo Comments » - Tags: journal, The Fulton School at St. Albans
December 29, 2011
November 25, 2011
A selection of "cheat sheets".
I let my students bring in one page of handwritten notes, a “cheat sheet” if you will, into their last Physics exam. I’d expected to see some very tiny writing, but some of the notes needed scientific-grade magnification equipment to be read. Seen from a distance, the dense writing did have a certain aesthetic appeal.
Of course the primary reason for letting students bring in the cheat sheets into the exam was to get them to practice taking notes. At one extreme, the students who already take good notes benefit from having to condense them. At the other extreme, the students who don’t take notes at all get a strong incentive to practice. The very act of preparing cheat sheets is a good way to study for exams.
And it worked. As they hand in their papers I usually ask them how the test went, and, this time, I also asked a few student if they found their page of notes useful. One student in particular responded, Well I didn’t need to use it after making it.
Cheat sheets laid out according to note-taking style. Two extremes of note taking styles are highlighted. Equations and diagrams to the left, and text-only to the right.
It was also very interesting to see the different styles of note taking: the strategic use of color; densely packed text; equations; diagrams; columnar organization. What all this means, I’m not sure. I’m particularly interested in how their note taking style relates to students’ preferred learning style.
Indeed, it would be interesting to see if the note taking style co-relates in any way with students’ performance on the test. One could hypothesize that, since we know that students learn better when they encounter material from multiple perspectives, then students whose notes have the greatest mix of styles — diagrams, equations, text etc. — should have learned more (and perhaps perform better on the test).
It’s a pretty simple and crude hypothesis, since there are likely many other factors that affect test performance, but it would still be interesting to look at.
Citing this post: Urbano, L., 2011. "Cheat Sheets", Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in Classroom Notes, PedagogyNo Comments » - Tags: journal, learning styles, my art photos, note-taking, Pedagogy, tests
October 15, 2011
Early morning.
The first few mornings at Heifer were cold. About five or six degrees Celcius (in the 40′s Fahrenheit) at sunrise. The large barn we slept in had been “converted” from housing horses to housing people. Apparently, horses prefer wide-open, drafty places.
But a warm sleeping bag goes a long way. And being forced to wake up just before the break of dawn does have certain advantages. I’m rarely up and about in time to capture the morning light. With the early morning fog drifting across the slopes and rising off the lake, those first few mornings were wonderful for photography.
Sunrise is usually the coldest time of day. After all, the Sun’s been down all night, and is only just about to start warming things up again. Cold air can’t hold as much moisture (water vapor) as warm air, so as the air cools down overnight the relative humidity gets higher and higher until it can’t hold any more – that’s called saturation humidity; 100% relative humidity. Then, when the air is saturated with water vapor, if it cools down just a little more, water droplets will start to form. The cooler it gets the more water is squeezed out of the air. Water vapor in the air is invisible, but the water droplets are what we see as fog. Clouds are big collections of water droplets too; clumps of fog in the sky.
Early morning fog drifts over the lake.
Citing this post: Urbano, L., 2011. Fog on the Downs and Lake, Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in Art, immersion, Natural WorldNo Comments » - Tags: heifer immersion, immersion, journal, my art photos, photographs, weather
October 9, 2011
Picking green beans at the Heifer International Ranch.
We worked in the fields this afternoon: picking beans and planting garlic. Clear skies with a cool, early October breeze; warm, but not hot.
It was enjoyable work. The fields were small and there were a lot of us. Lots of conversation.
We picked somewhere close to 64 lbs of green beans, which, according to our guide, sells for somewhere around six dollars per pound (organic beans). Three hundred and eighty four dollars. Took us about an hour.
Earlier in the morning, we’d had a discussion about Community Supported Agriculture (CSA). Heifer ranch is a CSA. People from the surrounding towns buy shares in the annual crop, and the ranch brings them a basket of produce every week for the season. CSA’s are great: fresh local produce, for about the same price as in the store. You tend to get a broad enough variety that it helps expand your cooking repertoire. And you avoid all the externailties from long distance transportation and factory farming.
Finding out how much workers make in CSAs vs industrial agriculture.
They (our guides) had compared CSAs to the “typical” industrial agricultural system. Students read out notecards as they went through the all the jobs of the people who get your tomatoes to you. One student, who represented the energy going into the system, had to do a lot of jumping-jacks and pushups – situps too. There are eleven different jobs in the industrial system, with the people actually picking the crops – migrant workers – getting one cent for every dollar you pay at the store. They are three jobs within the CSA, and the farmer gets 80% of the sale price.
The presentation was a little problematic, unfortunately. Heifer is a CSA after all. Trouble started with our facilitator’s terminal question, “So which one do you think is better?” The first response was, “Well with the economy these days, won’t you loose a lot of jobs with the CSA?”
Fair point. But it might be argued that the industrial system might take one big farm and 11 jobs to bring 1200 tomatoes to market, it might take 4 CSAs, and about the same number of jobs (12), to do the same. Although the each person in the CSA system gets a little less, the money is more equitably distributed.
The second question, cut to the crux of the problem, “But what are the notecards leaving out?” Cynical? Perhaps. However, I’d like to think of it as healthy skepticism.
So now our guide was stuck. How could she, an obvious advocate for CSAs, convince the skeptical? Not easy, perhaps not even possible. By being too strong of an advocate for her side, she’d have a hard time convincing even the impartial.
It’s not easy making an argument that you’re passionate about. Not at all.
Snapping green beans. Students agree that beans you pick yourself taste better.
I made sure I had a small discussion with the more skeptical students, to make sure they realized that even if you distrust the credibility of someone, you can often learn something useful. In fact, that’s why you should always look for multiple sources of information. Also, while CSAs are great for some things, local farms in Arkansas or Missouri aren’t going to be producing a lot of tomatoes in January.
That’s why I’m glad we picked the beans later in the day. And it was important that we did the accounting.
It took sixteen of us one hour to pick $384 worth of beans. That works out to 24 bucks per person per hour. Since the migrant workers only make 1% of the final cost, we would have made about 24¢.
24¢ for an enjoyable hour of gardening on a pleasant day. But what do you do when you’re hot and miserable in the middle of the summer, and hour after hour after hour of the same work is what you need to feed your family. And you’re missing school to do it.
Planting garlic.
I’m not sure that students will intuit the difference between what we did and what migrant farm workers do; neither the time we put in, nor the effort we expended were anywhere near equivalent.
I think making that distinction is important. Recognizing what migrant workers do, many who are the same age as my students, might make the point of what organizations like Heifer and Human Rights Watch are trying to do better than just talking about it, or simulating it, in the classroom.
I think it might make a big difference to hear the voices of these workers.
So I’ll show the HRW video advocating for the CARE Act to reduce child labor among teen migrant workers, and see if it has an impact.
Citing this post: Urbano, L., 2011. 24¢ per hour, Retrieved May 19th, 2012, from Montessori Muddle: http://MontessoriMuddle.org/ .
Attribution (Curator's Code ): Via: ᔥ Montessori Muddle; Hat tip: ↬ Montessori Muddle.
Posted in Experiential, immersionNo Comments » - Tags: agriculture, child labor, compassion, consumerism, heifer immersion, immersion, journal, reflection
