Hi. It's Paul Andersen and this is Science and Engineering Practice 7, Engaging
in Argument from Evidence. When I see the word argument I tend to think of the word
fighting, like they're having a fight where there's a clear winner and a loser. But that's
not what this practice is really about. Because argument is important in science and engineering.
Because what it give us in science is the best explanation for how the universe works.
And in engineering it gives us the best solution. And so to understand argumentation we should
look through a little bit of history. History of science. And let's look at the universe.
So in the 1500s and 1600s there was much debate over what the universe was like. What it looked
like. And what accounted for the movement of the sun through the sky and the movement of the
planets. And there were basically two models. There was the geocentric model. And that was
this idea that the earth sits at the center of the universe and then the sun and the planets
move around that. And there was a real elaborate ptolemaic system that explained how these
planets moved. And then the new theory was this heliocentric theory. The idea that the
sun sits at the center of our universe or really the solar system and then the planets
move around that. And so it wasn't as simple as one of these is right or one of these is
wrong. We have to gather a huge amount of evidence. We have to formulate arguments and
then critique other arguments. And so let me show you how intense this was. And so the
geocentric model had been developed by the Greeks and basically put the earth at the
center and then the sun would move around that. The planets would move around that.
When you look at this model it looks kind of crazy. But that's explaining why the planets
will show what's called retrograde motion. They'll move through the sky and then they'll
move back. And so basically if we run that forward in time, the geocentric model explained
these two things. Why the sun looked the way it did and explained why Mars would go forward
in the sky and then would tend to go backward in the sky for a little bit. And that's the
geocentric model. And that was really important just fundamentally putting us at the center
of the universe. There was something compelling about that. What's the heliocentric model?
Well basically that puts the sun at the center. And then the idea that the Earth and Mars
are going to move around the sun. And so these are two competing models. The first one was
developed by Ptolemy. And so this is a Greek. And beautiful diagrams and maps and formulas
to explain how everything moved. But what they didn't have was a lot of evidence. And
so the first one to put forward an idea of a heliocentric model was Copernicus, Nicholas
Copernicus. And so we sometimes call it the Copernican Revolution by putting the sun at
the center. And so he really started the ball rolling, but it wasn't until we gathered more
data. And so Galileo used his telescope, for example, to study Venus. And looking at the
phases of Venus to figure out that maybe the heliocentric model was correct. And then it
was kind of finished up by Isaac Newton who explained why the heliocentric model was right
and the geocentric wasn't. But it took, you know, the church hundreds years even to apologize to
Galileo because he was in prison for these thoughts. And so again the nice thing about
science is that there's a right answer. And we're able to march forward to that through
argumentation. And so how does that play out in current science? Well, there's basically
informal and formal arguments that are taking place. And so an example of an informal argument
would just be people talking. And so here are two famous scientists. This is Albert
Einstein and Niels Bohr. And what they're discussing is quantum theory. These new ideas,
like Heisenberg's Uncertainty Principle that explained the way improvements upon even Isaac
Newton's idea of how the universe works. And Einstein wasn't convinced and he just kept
coming up with good arguments. And then Niels Bohr would try to prove him wrong. As we look
back on it, Einstein was a really, really smart and it was important that he put forward
all of these arguments because it helped develop quantum theory as we see it today. Or maybe
you're a scientist and you go to a national symposium. So if you're a biochemist and you're
going to a national symposium, you get to meet with other scientists. Share your research.
Hear presentations. And so what you're doing is putting forward ideas and then you're sharing
those ideas with others. Or even in your lab, sharing ideas of what you're doing, what you
think. Explanations that you might have. I worked at a lab for a couple of summers and
we worked on biofilms. And every week we would have a meeting where we would talk about all
of the research that was going on and we'd share ideas. It's very important, these informal
arguments that you have in science and in engineering. We also have what are called
formal arguments. And this usually comes in the form of peer review. And so the way science
works is that people come up with explanations or theories. They're tested. They gather evidence,
and then when they're done the try to publish that in one of the respected journals like
Science or Nature. But you don't just get to publish an article in Nature. You have
to have it peer reviewed. And so basically you submit your request to one of these magazines
and then they're going to send out investigators to actually try to replicate what you did.
To make sure that this is a valid experiment. And a lot of scientists are trying to prove
you right or wrong. So that's the way that science works. If you're really looking at
the evidence that's collected and then we're reevaluating it. And that's the way that science
grows over time are really through these studies that are submitted to journals and then this
body of science just gets bigger and bigger and bigger over time. Now in engineering we
see the same thing. Argumentation is super important. A great example of this, I don't
know, you may have seen this, is Apollo 13. It's a wonderful movie, but it details this
trip to the moon that was somewhat flawed. And so let's listen to, this is coming from,
they're communicating with Houston. They just heard a huge bang and they're sensors are
going crazy. "Okay Houston, We've had a problem here." "This is Houston. Say again please."
"Houston, we've had a problem. We've had a main B bus under volt." "Roger. Main B Undervolt"
"Okay. Stand-by thirteen. We're looking at it." Okay so what they had was an explosion
of an oxygen tank on the service module and they had to eventually move over to this lunar
module so they could survive. And it presented engineers with all of these new problems that
they hadn't really had to deal with before. One of the big ones is that the scrubbers,
the things that get rid of carbon dioxide, in the service module didn't fit in the lunar
module. And so they had to come up with a solution to this problem. And so when they
really say, "Houston, we have a problem," that's what engineers deal with. They deal
with problems and they come up with solutions. And they eventually took, you know, inventory
of everything that was available to the astronauts and then they came up with a plan, a way to
build, I think the call it a male box, this way that we could really put a square peg
into a circular hole. And so engineering again is using explanations and using argumentation
to come up with the best design. And so what's the goal in science education? We want our
students to be able to construct arguments, critique other people's arguments and then
understand this whole idea of science and how peer review is super important. And so
what kind of a progression should you use in the classroom from elementary to high school?
How do we get kids doing this? How do we get them using argumentation from evidence?
And how do we get better and better over time? Or closer and closer to the bull's eye? Well
we want to start in the beginning. And the best place to start when you're dealing with
science is with a really good question. And so let's say we have a half a gallon of milk
right here and I were to take a nail and I were to pop three holes in the side of this
full container of milk? Now milk is going to come squirting out, but a good question
you could ask your students is what is that milk going to look like when it comes squirting
out the side of that milk container? And so what you want them to do are to construct arguments.
You want them to come up with a solution and then we use evidence to actually critique
each other's arguments. And so when I've asked this question in class, there are basically
three theories or three, excuse me, explanations that are put forward. First one is this, the
idea that these streams of milk will all converge at one point. There's another one I like to
call the rainbow hypothesis, that their going to form some kind of an arc like this and finally
there is C where you're going to get almost a cascade like that. And so the first thing
you want them to do is to construct their arguments. And then you want to use evidence
to support that. And so basically and you can do this as a classroom or you could do
this individually, is you want them to start looking at the other arguments. And one thing
you have to put aside in science is your ego. You don't want to be so attached to a answer
or to your guess that you aren't willing to look at other evidence. And so basically this
a great activity you can start with in the elementary levels, having them put forward
a guess and then kind of argue on the evidence. So maybe this person says that this one's
going to arch out farther because it has more time. Or this one maybe that it's going to
squirt out farther because it has more energy or there's more gravitational energy on it.
And so what is the right answer? Well a great way to do this is to actually do science with
it. Fill up one of these containers with water, pop three holes in it and then you can pull
the tape off. It's kind of keep that water inside there and what you'll find is the right
answer is C. But that's less important than this whole process of putting forward an explanation
and then arguing on that. And then the last one is the idea of peer review. And so we
really need our science students to understand that the way science works is people gather
evidence, they come up with explanations and then they publish that. To be published you
have to get in a journal and there's this whole peer review. And so that's how science
is made. That's not how bad science is made. That is how science is made. And so these
famous articles appeared in Nature magazine, which is one of the most famous scientific
journals. But each of them had to be peer reviewed before they were actually published.
And so argumentation is not a bad thing. It's a wonderful thing that makes science better,
makes engineering better, and I hope that was helpful.