Hi. It's Paul Andersen and this Crosscutting Concept 2. It's cause and effect.
Cause and effect is innate in humans. In other words from a young age we want to know why
something occurs. In other words, what causes the ripples on the pond? We want to know that
mechanism. We want to explain why it occurs. And so it's innate in us but it's something
that we also want to develop in a science classroom. Because in science, cause and effect
allows us to explain causal relationships. This effects that. And in engineering it's
a little bit different. We want to be in control of the cause so we can also control the effect.
Especially in a design. And so when you're presented with a question, cause and effect
comes right away. And so let me give you a good question. This is a rattleback. A rattleback
is a piece of plastic that has a unique behavior. And so in this video what I'm going to do
is I'm going to spin the rattleback and it will spin. I'm then going to try and spin
it in the opposite direction and it will rattle and then it will come back again. Let me try
that again. So I'm going to spin it like this. It's going to rattle. And then it's going
to spin back. And it wants to spin that way so much that if you just touch it, it'll start
to spin in that direction. Okay. Now I've given you a good question. And so what you
should be thinking is what's causing that rattleback to have that behavior? In other
words is it a magnet that's in here? Is it somehow asymmetrical? Is it somehow . . . a
weight inside of it? And so, our mind jumps to this idea of cause and effect. But one
thing that we want to make sure that students understand is that if we're saying A causes
B, then we have to have a chain of interactions from A to B. In other words we want to link
A to B. We really want to make sure that A is causing B. And sometimes that's super simple.
So if you see a home run, in other words a baseball go over a fence, you know the cause
of that home run. It's the bat that hit the ball, because you can physically see it. And
so now you have a nice chain of interactions. Since we can see that and we can video that
bat impacting on the ball, we can say that A is actually causing B. But sometimes it's
unclear. And so for a long history of humanity we didn't know what causes disease. We didn't
know what causes chicken pox for example. A lot of people thought it was just bad air.
And if you would have said to somebody that there's something on your hands that's causing
that disease and so you need to wash your hands, people back them would have been skeptical.
And the reason they would have been skeptical is that there's no chain of interaction. There's
not anything that we can see that's linking the washing of your hands to a decrease in
those infectious diseases. And until we had studies where we could actually prove that
or we could see the virus, we could see the bacteria, we really couldn't say that A causes
B. And sometimes those causes are really complex. And so if we were to look at an ecosystem
for example or if we were to look at climate. Global warming is a great example of that.
We know that the climate is getting warmer. So we can see that in the record. But we don't
know specifically all the causes of the that. We know that carbon dioxide is one of the
big ones. Greenhouse gas is one of the big ones. But there's so many variables at play,
it's hard to tell what are all of the causes. And also sometimes it's just a probability.
So if you're looking at a particle, what's the probability that we're going to get radioactive
decay? What's the odds of that? Well you can predict. You have a probability of how often
that's going to occur in a specific period of time. But we can't say it's going to happen
right now. And here's the cause and here's going to be the effect. And so one thing that
we want to make sure when we're talking at this root level of cause and effect, this
idea of universality. And it's an assumption that we make. In other words, in the universe
there are four basic forces. And those forces are gravity, electromagnetism and then the
strong and the weak nuclear forces. And so basically we're going to assume that the universe
is that same here as it is everywhere. We're going to assume universality, that these forces
are the same everywhere. And that's actually a pretty big assumption. One other thing that
we want to make sure that were talking about is the scale. And so if we're looking at something
at a large scale, like climate or let's get a little smaller, let's say the structure
of this protein right here, well that's definitely determined by all of the atoms that are found
within that protein. But even though we understand all of these interactions at the small scale
that doesn't mean we can predict what's going to happen at the large scale. Even though
what happens at the large scale can't violate those rules at the small scale. And so what's
the goal in a science classroom? We want to make sure that our students are starting to
see causation. Or link causation, cause and effect. Example, we would want them to see
patterns right away in the early elementary grades and then we want to explain the unexpected.
And so when you see that rattleback spin, that's a great example of something that you
would want to present your students with, so they can come up with a lot of different
causes that we can then test. We then want to move on to argumentation. So as we move
into middle school and high school, not only do we want them to put forward a cause but
we want to argue for that and give evidence for that. And so examples could be let's apply
theories to things that we are seeing. Let's apply laws that we have, laws of nature, to
observations that we make. And then we want to do that observed phenomena. So actually
seeing what's occurring and then trying to explain all of the causes that make it occur
and then try to make argumentation from that. And so where would this occur at the early
elementary grades? We want to basically start sensing patterns and we to take those patterns
and then try to link those to a cause. So a great example could be plant growth. And
so you could have kids growing plants and then we could see what's effecting that. So
water is clearly going to effect plant growth they might say. Light is going to effect plant
growth. But you want to come up with as many different causes as you can. You want them
listing those causes out. And then as we move into older grades, especially in elementary,
we want to present them with weird observations. In other words we want to present them with
discrepant events. And so a great example of one could be the moon. And so the moon
is going to go through phases, so a good question is if the moon looks like this, how are the
moon and the earth organized so that you can get something like that? And it's a great
thing you can do in the classroom where you take a model of the moon. You have a light
source and you can kind of figure out where do I have to hold the moon if I'm the earth
to get a shape that looks like it? As we move into middle school and high school, we want
to start using argumentation. In other words we want to go to theories, establish theories
to explain phenomena. And so why a lever works, we could go over that in a classroom, but
then we could present them with phenomena. And then they're going to try to explain that.
So that's a great one that I've done in class, where you put, once they learn that the load
and the distance from the fulcrum is related, you can give them a load on one side and predict
how far a load has to be on the other side so that you can get it to balance. And then
we want to give them harder problems as they move through high school. So this is a dead
zone for example. It's in the Gulf of Mexico. And every year we have this area in the ocean
where everything dies. And that's because of decreased oxygen levels. And so you want
them to come up with as many different causes as there possibly could be. You want to list
all of those and so then we could start doing some research or we can start doing some testing
to see which of those causes are correct. So cause and effect is innate in us. It's
really cool and so are rattlebacks. And I hope that was helpful.