I'm trying to work on figuring out how to prototype popular-level science content that forces active engagement. I don't know how to do that yet, either the how of what technologies to use or the what of exactly what I want readers to be able to do. So this is a starting point, using a lesson that I have done many times in the classroom. I'm not sure this is a great example of the kind of material to use this format with -- in many ways this is replicating the experience of being in one of my classes, which makes this not necessarily popular science, but let's see where it goes:
What are Newton's Laws? Do any of you recall what those laws are?
Insert tool for reader to reply with one or more of the laws, or a poll, or a dropdown list, or something
Most people I meet seem to recognize statements of Newton's laws when they hear or see them, and if I cue them with the first few words, they can often recite the rest. They often have the order wrong, and not so many people know the 2nd law, but they know some version of the first and third, and the order isn't really important anyway. So good job, here they are, for completeness in their most commonly known forms:
- An object in motion stays in motion, an object at rest stays at rest, unless acted upon by an outside force
- Force equals mass times acceleration
- Every action has an equal and opposite reaction
So cool, we know what the laws are, but I find that a lot of people have a hard time making use of them to be able to predict the results of specific phenomena, and that's really what we want, right? It doesn't really matter if you've got something memorized if you don't know how to use it.
Here's the scenario then. I have a tennis ball here. I'm going to walk across the room at a steady pace. I'm going to hold the tennis ball next to my hip, and I'm going to drop it. I'm not going to throw it, I'm just going to let go of it. If I weren't walking, it would fall straight down and land next to my feet, directly under my hip.
But I will be walking. And I will keep walking, at the same speed, after I let go of the ball.
So the question is, can you predict where the ball will land, in relation to my feet?
Insert poll tool here (I don't want it to display stats on other people's responses, just record the reader's prediction and show it to them later when asked.)
- Will it land in front of me?
- Will it land right next to my feet?
- Will it land slightly behind my feet?
- Will it land significantly behind my feet?
The overwhelming majority of people I have done this with, regardless of their educational level, will answer (c). Almost no one answers (a), a few people will answer (b), and a sizeable minority will answer (d).
Let me clarify, that I mean where my feet will be, when the ball hits the ground. At this point a few of the people who answered (b) will change their answers to (c).
Okay, now I'd like you to pause, and explain why you chose the answer that you chose. Imagine that you are talking to a friend, who isn't sure about what will happen. As gently as you can, explain why you think that your prediction is right. If you can, make use of one or more of Newton's laws in your explanation.
Explanation tool here
Okay, now the moment of truth. We're going to do the experiment and see what happens. Make sure you watch closely, I'll do it a few times, and we will discuss what we see to make sure we all saw the same thing and agree on it -- our brains are funny beasts, and if we aren't careful they can mis-remember what actually happened to make you think that your original explanation was correct even if it wasn't.
Okay -- here goes: video
And what did we see? That ball landed right next to my feet, right where my feet were when the ball got to the ground. Did you see that too? The ball landed next to my feet. I'll do it a few more times so you can assure yourself that I am not cheating with how I let go of the ball -- I'm dropping it, straight down, as I walk at a constant speed, and it lands right next to my feet.
Was your prediction right? Most people do not get this prediction right, I have found, and I want you to process why that is so we can get closer to a good explanation in our heads, and I want to tie it to a big picture idea by using Newton's laws to explain it. The Law we want is the first one. So turn to your neighbor and explain to them how the 1st law helps us to understand what happened here and why. The ball landed next to my feet. Why?
Explanation tool here
Okay, so my best explanation using the 1st law is that the ball was moving horizontally when I let go of it. So the ball was already in motion when it started to fall. That motion, the horizontal motion, must continue unless there is an outside force to change it. Are there any outside forces that could have or should have changed that horizontal motion?
So yes, there is air resistance, you're right. But it actually isn't as big as people think it is, and even if it is, it can't change the motion of the ball instantly. Since the ball is already moving, the force from that air hitting it would have to slow it down to a stop, and that would take time, during which time the ball will continue to move forward. If there weren't any air resistance at all, then the ball would travel at exactly the same horizontal speed that my feet are moving at, all the way down to the ground.
Okay, so record your best understanding of what happened and why, and I want you to include one more aspect this time -- Why was your first prediction wrong? What was it that you were thinking that explains why you thought what you did before we did the experiment. If you got the prediction right, you might have had the wrong reason. And if you got the prediction wrong, you might have had reasons that were good ones, that just missed something important. Can you think of examples of situations where the "behind you" prediction would be right? Is it possible that you were thinking of something like that, instead of this situation?
I often find that what people are thinking of is something more like the experience of dropping something out of the window of a car. Air resistance does matter in that case, because the car is travelling fast enough that the thing you drop is moving through the air at high speed when you let go. This means that there is a significant force from the air on the ball, that causes the forward velocity of the ball to decrease in magnitude much more quickly. This means that while the ball is falling downward, it is also travelling forward but slower than the car. So when it hits the ground, it seems to you, in the car, as though it has flown backwards, when it was actually fairly close to you when it hit the ground, and then it slowed down evern faster due to the impact with the ground.
Right then! Last explanation -- record your thoughts on what we've seen, your best explanation of what happened and why, using language from the 1st law, as well as your thoughts as to why your initial prediction was what it was.
And finally, got any suggestions or thoughts on follow-up questions or experiments? Based on this experience, is there some other phenomenon that you'd like to test your prediction on?
Use the comment box for suggestions, please!
- Does it need pagination so you can't move on without writing or submitting something at the checkpoints?
- Is this just directed note taking? How many people would just be annoyed by it?
- How do you store a reader's work so they can see it, without others seeing it?
- Is this just a textbook?
- What kinds of content is this idea well-suited to? What kinds of content is it not suited for?
- Editing. How to get the tone and style right to feel like a conversation without being annoying