It’s not as much of an issue in science (Natural World) but because it tends to pop up to the top of the search engines, my students tend to overuse Wikipedia, so I’m considering, at least as an experiment, blocking it. Wikipedia tends to be reliable in general, but its open nature, where anyone can edit also means that it can also be spectacularly wrong.
I use, and I encourage my students to use Wikipedia for two things, finding images that are not restrictively copyrighted (almost all images on Wikipedia are free for anyone to use since that is a specific part of their policy), and finding, at the bottom of the articles, the list of references to what are usually credible sources for the topic they are researching. While this seems to work well for science research, because Wikipedia’s articles tend to be too technical for middle schoolers, some of my students have been burned when using Wikipedia articles as a reference for their social world projects.
So I’m going to try blocking Wikipedia for a week and see what happens. Students can still use Wikimedia Commons for images, but they’ll have to find sources in other ways.
In researching the benefits of sleep to assist a student interested in sleep deprivation, I came across the work of Matthew Walker from UC Berkley. His papers have some rather intriguing titles. One of them (Walker and van der Helm, 2009), called “Overnight Therapy? The Role of Sleep in Emotional Brain Processing” finds that lack of sleep seems to result in us retaining more negative memories and emotions, and reduces our ability to act rationally (Yoo et al., 2007):
[S]tudies indicate that prior sleep loss significantly impairs the ability for effective next-day learning of new experiences across numerous species. Furthermore, sleep loss appears to disrupt the learning of different affective categories to varying extents, potentially creating an imbalance in negative emotional memory dominance. – Walker and van der Helm, (2009)
Walker’s also synthesized the current research on sleep and finds sleep is important in other types of memory as well. During sleep we organize information in our brains, finding context for the data we absorbed while awake, which is why we remember things better after we sleep.
[S]leep serves a … role in memory processing that moves far beyond the consolidation and strengthening of individual memories and, instead, aims to intelligently assimilate and generalize these details offline. – Walker (2009)
Walker’s bibliography is a treasure trove of information about research on the affects of sleep on our emotional and intellectual well being. These articles will, however, probably need a lot of translation for the typical middle schooler. For that reason, using the press reports on this work would be a much better alternative for students.
To accurately observe nature sometimes takes time. Land-labs are intended to get students out into nature for a week at a time throughout the entire year so that they can see the change in the seasons. But sometimes you need to winnow things down, speed things up, to observe the slow changes that you just miss. Time-lapse photography is one great way to do this.
Yesterday, one of our experimental loaves of bread failed to rise, so re-tried it today and had a discussion about all the things we can do encourage it to rise. Since yeast is an organism, and we talked about the role of yeast in baking bread yesterday, this was a chance for the students to take what they’d learned and extrapolate into a new situation.
These types of situations pop up all the time in the student run business, especially when we try something new. It gets to the critical thinking skills adolescents need to practice. It is the reason Maria Montessori advocated for a boarding house middle school that ran a business. It is one of the reasons I insist that we start at least one new business every year in addition to our core pizza business.
Although I’m pretty sure I’d explained this before, I had a student ask me today what makes the bread rise. He’d been combining the ingredients to make bread for the student run business with a rather thoughtful look on his face. So I told him that yeast is a fungus that “eats” the sugar in the honey and “releases” carbon dioxide bubbles, which get trapped in the dough causing the bread to rise.
I could see the look of disgust racing across his face at the mention of fungi, so I asked, “Would you like to look at it?” He did, and he was not the only one. So after lunch I broke out the microscope, which we have not used much this year since we’re doing the physical sciences this year. A slide, a cover slip, a drop of the residue from the glass jar we used to mix the liquids for the bread, a quick (so very quick) demonstration of how to use the microscope and whallah.
Under 10 times magnification you could see hundreds of cells moving across the field of view. The students were impressed by how many there were. Under 40 times magnification you begin to see cell structures.
Image from Wikimedia Commons, but yeast under the 40x microscope objective looks pretty similar.
We’ll look at yeast again next year when we’re focusing on the life sciences, but when I think of the Montessori axioms that the role of the teacher is to prepare the environment and to follow the child, I think of situations like this. At this time, in this place, after kneading dough for half a year, the student asked the question, and everything was ready for him to answer the that question and whet his appetite for more.
My students know my weaknesses too well. I had a well crafted argument today that I should let them watch Judson Laipply‘s YouTube video, “Evolution of Dance“. The gist of the argument was that they never really understood evolution until they saw the video (we covered evolution last year); the way the dance moves evolved, with small changes from one to the other is an excellent analogy for the gradual evolution of organisms. The best example was how The Robot changed into Breakdancing. I let them watch it of course, it was a good argument and the video is pretty harmless. And if it actually helped them learn about evolution ….
I came across this beautiful animation of the auroras on Saturn. The auroras are caused by charged particles (ions) from the sun, the solar wind of protons and electrons, are focused down onto areas near the poles of a planet by the magnetic lines of a planet’s magnetic field. The ions hit the atmosphere colliding with atmospheric gas molecules like nitrogen and oxygen causing them to become excited and spit out electrons (becoming ions themselves). Molecules are not “happy” when they’re missing electrons so they’ll capture one to become “fulfilled” (fill their outer electron shells). It’s when they recapture electrons that they give off the light that we see as the auroras.
On Earth the auroras are green or brownish-red (from the Oxygen) and blue or red (from the Nitrogen). Saturn’s atmosphere is mostly hydrogen and helium so we’re not quite sure what color its auroras are. The auroras in the animation were colored in by NASA since the camera on the Cassini spacecraft is black and white.
The video clip below gives a nice explanation of auroras.
On the last morning of our immersion trip we had a choice between going to Hot Springs, Arkansas, with its geothermal springs and another museum, or hiking at Lake Catherine where we had spent the night. Since we’d been to two museums on the previous day, we pretty unanimously chose the hike. And it was great.
Conchoidal fracture in quartz (image by Eurico Zimbres FGEL/UERJ via Wikimedia commons)
We took the Falls Branch Trail, which follows a couple of young, boulder-choked creeks that have are carving steep-sided valleys through nice clean limestone bedrock. The students were constantly bringing me rocks to identify, and they were almost invariable limestone, with a few pieces of quartz thrown in. The limestone was so clean that it was near translucent (fairly close to marble) and the cobbles in the stream bed were easy to mistake for smoky quartz, particularly if they were rounded enough that you could not look for quartz’s characteristic, curved, conchoidal fracture. Quartz also tends to be a lot harder than limestone, but the ultimate test, which the students really wanted to see, is to put acid on the rock. Limestone fizzes. I did not have any limestone on this trip (note to self: get some HCl for next time), but this little experiment is a nice follow up for our discussions of ionic bonding in chemistry. We have some limestone samples back at school so I plan on doing this as a follow-up.
Quartz vein (white) cutting through a limestone boulder.
Because Lake Catherine is very close to Hot Springs, it would not be surprising to find some quartz. The hot water that’s coming out of the springs flows up through cracks (faults) that extend deep beneath the surface. The deeper basement rocks are silicates, the granitic rocks that make up the continental crust, so the hot water dissolves some of that silicate material, and when the water cools down, ever so slightly, as it approaches the surface, some of those silicates will precipitate out to coat the walls of the faults with quartz. Sometimes they even fill up the faults entirely, leaving quartz veins.
The stream bed, being of young geological age, was a series of small waterfalls culminating in the five meter high drop that gives the trail its name. The water was clear and cold but with that beautiful aquamarine tint of dissolved limestone. There’s a whole lot more I could say about plunge pools and migrating nickpoints, but I’d probably go on too long. Besides we did not take the time to talk about those since there was so much else to see.
Interference pattern in ripples.
When we reached estuary of Falls Creek and Lake Catherine, the lake’s water was so calm that the kids started trying to skip stones. This of course provided a beautiful opportunity to look at water waves and interference patterns. As the ripples from each skip of the stone expanded, they melded. The constructive interference was easier to see in the field because it made for bigger ripples. But the photos show the destructive interference very nicely.
This was an excellent hike. We were a little pressed for time since we needed to get back to school before the end of the school day, but next time, I think, I’ll have us pack our food in and have lunch on the trail overlooking the waterfall and the lake. The ability to use these types of outdoor experience to integrate the academic work is one of the main reasons I enjoy the Montessori approach to middle school. All through the trip back though I kept thinking about how I could organize things so that we would never need to see the inside of the classroom again.
