Food scraps get composted as part of our school lunch compost program. We use the compost as fertilizer in our school garden. How do we explain decomposition? What causes it to happen? How long does it take different food items to decompose? How does food turn into fertilizer? What kind of environment is required for decomposition? Does trash decompose at the same rate as food scraps? Where does all our trash go? What are the benefits of composting and recycling? What factors do engineers consider when building a landfill? Grade 6 students investigate.
Currents are like rivers in the ocean. What factors or forces move the large masses of water along the surface of the ocean to create the world's ocean currents? What patterns do you notice? In what ways are the currents important?
This Hubble telescope image released in June 2014 contains approximately 10,000 galaxies, extending back in time to within a few hundred million years of the big bang. Researchers say the image, which includes UV light, provides the missing link in star formation. The most distant galaxies appear to us in their most primitive stages due to the significant amount of time required for the light of distant stars to travel into a visible range. Link to celebration of 25 years of Hubble. Link to NASA video about detection of exoplanets. Link to Future Engineers design challenge: design a space tool. Link to NASA's DIY Podcast topics. Below are student questions inspired by the Hubble telescope image we viewed. Homework over winter break: 1) Download the Star Chart app and make observations of the night sky in winter. What two constellations are high in the sky at midnight on New Year's Eve? 2) Watch episodes of the documentary Cosmos: A Spacetime Odyssey on Netflix (if possible). Energy Investigation: Sound Energy Investigation: Light Energy Investigation: Heat (Electrical, Mechanical, Chemical) Now, let's play the explanation game! Explain the energy phenomena you experienced. Remember to make a claim, then use evidence and reasoning to support your claim.
The story of the Ebola outbreak in Africa and its recent spread to the U.S. has been prominent in our world news. Lately, many students have been asking me questions about Ebola. Students posted these questions on our question board: What causes Ebola? How does a new disease start? Why do viruses (and things that kill) spread? Do you think Ebola will spread to Utah? Is there a cure for Ebola? Will Ebola end the world if no one finds a cure? It was clear that some students felt afraid. We had been studying the role of microbes in ecosystems, including their important role in the food chain and as decomposers. When student interest shifted to Ebola, we began to study the harmful effects of microorganisms. The students had some real concerns. I wanted to help students talk about their concerns, understand the science of a disease outbreak, and channel their emotional energy into finding solutions. Because when we think like scientists, we focus on solving problems. One morning as students arrived in the classroom, I handed out black squares of paper to about half of them. I explained that the students holding a black square of paper had contracted a deadly disease. I asked them to come to the front of the classroom. The living students were asked to determine the source of the disease by examining the patients closely. That is, they had to find something that all the patients had in common. After some time, a student cracked the case. All the dead patients were wearing black shoes, and all the survivors were not wearing black shoes. I explained that years ago in 1854, John Snow used this same strategy to identify the source of a cholera outbreak in London. He was the very first disease detective, or epidemiologist. (We viewed this story here on PBS.) His methods recently helped modern epidemiologists identify mosquitoes as the source of the deadly West Nile virus in the U.S. back in 1999. (We viewed this story here on PBS.) So, what have epidemiologists discovered about the source of the Ebola outbreak? And, how does Ebola compare to other deadly disease outbreaks in our history? We made a list of the deadliest diseases we could think of (shown below). I was surprised that students were aware of so many deadly diseases. In addition to Ebola, they listed the Black Death, small pox, malaria, tuberculosis, and yellow fever. Interestingly, the majority of students (16/24) thought Ebola was the deadliest disease in history. To learn more, we next did a write-the-room activity. Students moved about the room recording facts in their science journals for eight different diseases, including the number of deaths, how the disease was transmitted, and the type of microbe that caused the disease (bacteria, protist, fungi, or virus). Students were surprised to discover that Ebola is a relatively rare disease, so far killing about 5,000 people. Other disease epidemics have killed millions, including AIDS (25 million), the Spanish flu (50 million), and the Black Death (75 million). We reflected back on the student's question: Will Ebola end the world? Not likely. Learning more about other deadly diseases put the Ebola outbreak in perspective for us. The following class period, we viewed segments of this documentary here about Ebola. The documentary answered some of our questions about how the Ebola outbreak started (people eating infected fruit bats in Africa), how the disease is spread (touching body fluids), and what scientists are doing to find a cure (developing the drug ZMAPP). The next week a flu shot clinic was held at our school. By raise of hand, we noticed that not many students had gone to receive the flu shot. What factors influenced our decision? We reflected on the fact that most people in our classroom are alive today because of vaccinations and antibiotics. We viewed the story about the discovery of penicillin antibiotic here and here. And, students were curious to know what diseases they had been immunized against as a baby. I encouraged those that were interested to do some research on this topic, and invited them to learn more about how vaccinations work here and here. As we continued to learn more about the science of infectious diseases, I noticed a shift in the kind of questions students were writing on the question board. I saw their thinking shift from a fear of Ebola, to solving the problem of Ebola. Four students wrote questions that were particularly powerful: 1) How do bats survive the Ebola virus they spread? Wouldn't the cure in the immune system of bats help humans? (He thought a study of the fruit bat's immune system would help us develop a cure for Ebola in humans.) 2) Is Ebola similar to another epidemic? If so, how did we get rid of the first one? (She thought a study of the past would help us solve the problem of Ebola today.) 3) How will we stop Ebola [in Africa] if people [in America] won't help pay for the cure? (She was thinking about how to solve the economic and ethical problems related to stopping Ebola. That's thinking like a global citizen.) 4) How do vaccines work? Is there any way to prevent Ebola? (She was thinking about how to prevent future outbreaks of the disease.) I was pleased to see this shift in students' thinking. Students were no longer simply reacting to Ebola; they were thinking about ways to solve the problem of Ebola. To continue our focus on problem-solving, I explained that in addition to scientists and doctors, engineers and computer scientists are also important problem-solvers in our world. For our final project, we would get to do the work of engineers and computer scientists. Our task was to program a "bug zapper" that could be used to sanitize hospitals. The project was inspired by Xenex the disinfecting robot and brought to life by the Sphero balls we acquired this year as part of a STEM grant awarded to our school district. The real Xenex robot flashes a UV light to kill any microbes, including Ebola virus, present in a hospital environment. In our simulation, students were asked to program the Sphero ball robot to navigate through a hospital (see floor map above), stopping to flash a light in each room (or corner of the square).
Many students LOVED this project. In fact, several students commented to me that they are now asking for a Sphero ball for Christmas! I had three groups of students complete the challenge, and other groups partially complete the challenge. I did see some frustration at times, but I was proud of the great effort students put into this project. Students who enjoyed doing the work of engineers and computer scientists were encouraged to learn more about coding at home using resources available at code.org. That wraps up our study of microorganisms. In addition to learning some new content, I think students got a taste of what it feels like to be a critical thinker and problem-solver. They also got to experience what it feels like to collaborate with their peers on a project. And I saw evidence of their growing desire to be good global citizens. For example, many expressed their interest in helping people in Africa by donating money. Our hearts go out to the victims of Ebola and their families, as well as the hundreds of medical workers who are making a great sacrifice to help others in need. You are real-life heroes. Grade 6 students recently discovered that microorganisms act as decomposers in our school compost. We decided to further investigate the role of microorganisms in our environment. We went on a walking field trip to Beus Pond, taking notes on the diverse plant and animal life there (most of which depended on microorganisms for food). We also collected water samples, with the hope of viewing pond microorganisms under the microscope. Unfortunately, we found none. We are currently troubleshooting why this might be. Meanwhile, we pulled out the laptops and found some movies of microbes commonly found in pond water on the Internet. Students illustrated a few different protists in their science journals, then described how each one moved (using cilia, a flagellum, or pseudopods). Birds at the pond are not the only creatures who eat microorganisms. We looked for microbes in our food and found bacteria in our yogurt! We stained the bacteria with methylene blue to make it easily visible under the scope. (So cool!) Next, students worked in small groups to design an experiment that would test the growth conditions for yeast. Yeast is a fungus used to make bread and other foods. The variables we tested included different food sources (i.e., honey, salt, syrup, and flour). We used the carbon dioxide gas produced by yeast as an indicator of growth. We captured the gas in balloons, comparing the gas produced in each tube relative to the control. In the experiment shown here, the red balloon is the control and the yellow balloons are the variables. We discovered that yeast can eat anything with sugar (including syrup or honey), but not flour or salt. Students recorded these observations in their science journals. By the way, the lovely smell of the yeast experiment was a nice contrast to the stink of our previous experiment involving the decomposition of a potato.
Now that we have seen how microorganisms can be helpful, it's time to shift gears and study how microorganisms can be harmful. We have a lunch compost program at our school. Grade 6 students volunteer in the lunchroom to help younger students remember to compost their leftover fruits, veggies, and napkins. The volunteers also weigh and chart the compost before emptying the lunch scraps into our three-tier compost bin. When I met with 6th grade students for the first time, I invited students to tell me what they know about the lunch compost program. I am new to the school, and was curious about how it works. The students described the process and explained that the compost is used to fertilize their school garden. When I asked the students how the food turns into fertilizer, they realized they didn't know. A few students raised their hands and tried to guess. One student thought worms were important because he had seen a compost that used worms before. He said maybe the worms break down the food. (They eat it and poop it out?) Another student said time was important. It takes a long time for the food to break down, and maybe heat from the sun was needed. But students were mostly stumped. They added a question to our question board: "How does food break down and turn into fertilizer?" Next I asked the students if they'd like to see the compost bins in the back of the school. While most students knew the compost bins existed, they had never seen them before. So we went outside to make some observations. We observed that fruit flies were all over the fresh lunch. When I opened the middle chamber door to examine the older soil more closely, tons of worms started pouring out. This got quite a reaction from the students! We now had evidence that worms ARE important for decomposition! We took a sample of soil from the compost. Then we moved to the garden to make more observations. We compared the garden soil to the compost soil. I invited students to search the garden to see if they could find decomposition happening. They discovered a pumpkin and a squash decaying. They also discovered what they called "mold" covering the leaves of one of the zucchini plants. I asked them if they thought mold was important for decomposition. They agreed that mold did play a role in the decomposition of food. We are going to keep thinking about mold. What is mold? When we returned to the classroom, I invited students to work in small groups to design an experiment that would answer some of our questions about decomposition. I provided each group with a potato and three test tubes. I didn't give them much more guidance than that because I wanted to see what they were capable of on their own. Overall, I was impressed by their good thinking! One group tested the effects of temperature on decomposition, and another tested the effects of dry vs. wet soil. I had groups compare the rate of decomposition with and without worms, or with and without fruit flies. I had a group compare how a potato vs. yogurt decomposes. (They were curious why you can't put dairy or meat in the compost bin.) I have another group who asked to test the effects of salt and vinegar on decomposition. So I found some vinegar and salt in the cupboard and let them have at it. We had quite the variety of experiments! Two weeks later, students emptied the contents of their test tubes to make observations and record the results in their science journals. As you can imagine, our classroom quickly became very stinky! But students learned a lot about decomposition, and generated further questions for us to study. The question of the day was: Why does decomposition stink so bad? I invited a professional gardener to visit our classroom to teach us more about composting. We asked Mrs. Marvel if compost is supposed to stink. She says no. She taught us what we can do to reduce the stink at our compost bins. We need layers! Students volunteered to bring grass clippings, dead leaves, and chicken manure from home. We will continue to work on our compost over winter in preparation for spring planting. We identified microorganisms as the main source of the stink, and had a group discussion about the role of microbes as decomposers in our environment. How can we learn more about microorganisms? We will start by learning how to use a microscope. We want to see what microorganisms look like. But where can we find microorganisms to look at? We will keep thinking. Meanwhile, Mrs. Marvel helped us plant our fall crop of kale, spinach, peas, and carrots. We purchased compost and manure for fall planting. It cost us $65 and filled only two garden boxes. But come spring, we should have our own homemade compost from garbage...for free! Thank you microorganisms! (Decomposition is so cool.)
I love these photos of the students' hands in the soil. The warm, crumbly soil felt so good between our fingers. Interestingly, the store-bought compost we mixed together didn't stink. It smelled good, like earth. (Why is that?) |
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