Upper El (Mr. D): Carrying Capacity and More!

This week we worked on finalizing our Science Fair procedures, so the steps of our experiments are clear. Then we went deep into a science concept called carrying capacity to answer why we are considering bringing human life to other planets?

Last week, students spoke up and asked me why? Why are we thinking about sustaining life on another planet? That's where we started on Monday. First, I asked our group what they thought. Why might it be important to consider that question?

Asteroids! Global Warming!

Sure, these are problems to consider. But, I think there's another way to come at this. I explained a concept called carrying capacity using a theoretical island full of carrots and rabbits. There are a ton of carrots and only a few rabbits. What happens next?

The rabbit population grows!

And what happens to the carrots? Eventually, we reach this point where the rabbit population grows to exceed how many carrots can feed them all. So, some rabbits die—sad face. This allows the carrots to expand in number, and then the rabbits can grow in population again. This point, where the island of carrots can support no more rabbits, is the carrying capacity for rabbits on that island.

This is a pretty deep lesson, so we spent a few minutes making sure we understood it. Then, to the next question: do humans have a carrying capacity on Earth? We might say the obvious answer is, "of course," but I wanted us to think it through thoroughly. What could humans have done on that island that rabbits couldn't?

We can farm! We can make shelter!

Yea! Exactly. We're pretty special. We aren't limited in the same way, but the question is, are we still limited overall? I broke our class into five groups to think a few questions over.

The first was to make a list of two things. What factors help to expand our carrying capacity on Earth? The example we used was farming and agriculture. Then, what factors limit our carrying capacity on Earth? I wanted our class to go beyond just natural resources, so I gave them the thought of war. Wars don't help our population grow!

The second question was to imagine a perfect world—all that we could control was executed perfectly. For instance, since wars are within our collective control, imagine those are gone from our limiting factors. After all of that, do we still have a carrying capacity?

Finally, and the hardest one, whether you think we have a capacity or not, how could we try to calculate it? I didn't want anyone to try to get an actual number but to think about how we might approach getting to one. There is no definitive answer that I could find on this question anywhere. So, maybe Upper El could think of a way to get an answer!

I admit that I thought our groups would be finished thinking things through within a half hour or so. However, our groups worked the rest of the day on Monday and through Tuesday as well on these questions! I am really impressed with how much thought they put into this. While students brainstormed together, I pulled students to go over their Science Fair procedures and give them notes on their last story.

On Thursday, we got together and shared. We focused mainly on the first question. Factors that expand vs. limit our carrying capacity on Earth. We wrote a huge list together, students filling in things they didn't think of onto their own lists. Also, we challenged each other's ideas along the way.

When we return, we will continue looking at the other two questions. The goal of this whole exploration is to understand a couple of things. As we look at this idea and into sustaining life on another planet, we can get a clearer picture of how important sustainable living is, how important engineering and innovation is, how important cooperation and community is, and also how problem-solving with a larger perspective in mind can make for better, longer-lasting solutions.

I also left our group with the basic details of our next engineering project for when we get back. Thinking about increasing the use of our space on Earth and dealing with natural events like earthquakes and hurricanes (two limiting factors for carrying capacity), students will design and build a tower that can withstand the shakes of an earthquake and high winds of a hurricane.

I have some other great ideas for this project (in my opinion 😜). First, this will be a group project. Sometimes, this is hard for us, but learning to work together is a huge part of solving problems. After a deep talk with one of our group, I agreed that at any moment, if a member of a group is not feeling heard, they can call in Mr. D, the mediator.

The second thing, which this class of budding entrepreneurs will love, is that I will put a cost on our materials and keep track of each team's expenditures. I'll be the banker and seller of goods (straws, popsicle sticks, tape!). There will be a small prize for whichever team's tower withstands the earthquake and winds and spends the least "money." I'm really excited to get into this when we get back!

That brings us to Friday, which I'm sure all our parents have heard a lot about already. A fun day with students giving secret Santa presents, making gingerbread houses (which were all melting from how warm it was outside!), and of course cookies, hot chocolate, assorted other snacks, and Christmas Chronicles!