Randall Munroe: Can Math Answer Absurd Questions? When Randall Munroe volunteered to teach physics to high schoolers, his textbook approach to teaching the subject fell flat. Then he realized a way to get the kids excited about math -- Star Wars.
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Can Math Answer Absurd Questions?

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Can Math Answer Absurd Questions?

Can Math Answer Absurd Questions?

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GUY RAZ, HOST:

It's the TED Radio Hour from NPR. I'm Guy Raz. Back in 2009, this guy named Randall Munroe volunteered to teach a weekend class at MIT to a bunch of high school students.

RANDALL MUNROE: They have a program where people can come in and teach classes on whatever subjects they're interested in, and a bunch of students come and sign up and take them. And I had some friends do classes on root beer tasting and other ones do a class on, you know, programming.

RAZ: So Randall decided to teach the one subject he knew a little something about.

MUNROE: So I did a class on the physics of energy.

RAZ: Because he'd studied physics in college. But on the first day of that class, he was teaching, when he was giving his first lecture...

MUNROE: Well, I was talking about how you can define this quantity called potential energy, and you can calculate if you lift an object that weighs, you know, 5 kilograms through a distance of 2 meters, then it will have about 95 or, you know, 100 joules of potential energy.

RAZ: This approach, of course - well, not a big hit with the kids.

MUNROE: The students got kind of bored, just like I always did in physics lectures.

RAZ: And at that moment, it occurred to Randall that he was just throwing numbers at these kids that did not apply to anything in their world.

MUNROE: And it's just as abstract for me. You know, I never run into a 5 kilogram weight in my life. You know, I run into, like, gallons of milk or, you know, a cat might weigh 5 kilograms.

RAZ: And then, standing in front of his class that day...

MUNROE: I realized that part of what makes math and science so exciting is having questions you want to answer.

RAZ: So he thought, what kind of question would you want to answer if you're the kind of high school kid who signs up to take a class on the physics of energy on the weekend?

MUNROE: And at that point, I had a moment where I thought, wait a minute...

(SOUNDBITE OF JOHN WILLIAMS SONG, "STAR WARS MAIN THEME")

MUNROE: "The Empire Strikes Back."

(SOUNDBITE OF JOHN WILLIAMS SONG, "STAR WARS MAIN THEME")

RAZ: Specifically, this question.

MUNROE: When Yoda lifts Luke's X-wing out of the swamp, how much energy did that take?

(SOUNDBITE OF FILM, "STAR WARS: EPISODE V THE EMPIRE STRIKES BACK")

FRANK OZ: (As Yoda) Use the force, yes.

RAZ: Right, that scene where Luke's fighter plane's trapped in the water.

MUNROE: And it's a really straightforward calculation. If you can figure out the mass of the X-wing...

(SOUNDBITE OF FILM, "STAR WARS: EPISODE V THE EMPIRE STRIKES BACK")

MARK HAMILL: (As Luke Skywalker) Right, I'll give it a try.

MUNROE: ...You know, and how high he lifts it.

(SOUNDBITE OF FILM, "STAR WARS: EPISODE V THE EMPIRE STRIKES BACK")

OZ: (As Yoda) Try not - do or do not.

MUNROE: And what the strength of gravity on Dagobah is.

(SOUNDBITE OF FILM, "STAR WARS: EPISODE V THE EMPIRE STRIKES BACK")

OZ: (As Yoda): There is no try.

MUNROE: And the students suddenly got really interested in figuring out, OK, how much does an X-wing weigh? Is there a canonical value for the gravity on Dagobah? Like, oh, well, there's a Star Wars Wikipedia, we can look up the weight of the X-wing there. And they were suddenly, like, kind of running ahead of me and figuring things out before I could even get to them. Then I realized, like, oh, this is the missing piece.

(SOUNDBITE OF FILM, "STAR WARS: EPISODE V THE EMPIRE STRIKES BACK")

OZ: (Yoda) Size matters not. Look at me. Judge me by my size, do you?

MUNROE: Answering these interesting questions.

(SOUNDBITE OF JOHN WILLIAMS SONG, "STAR WARS MAIN THEME")

RAZ: All right, it's time to embrace your inner nerd because today on the show, we're solving for X - stories and ideas about how numbers shape our world and our lives.

HANNAH FRY: How people talk about themselves, how people interact with each other, how people present themselves when they're looking for a partner.

CLAYTON CAMERON: When I listen to other musicians say, man, he really sounds good when he does that, you know, what is that?

KEVIN SLAVIN: How do we even get our heads around the algorithms that are used online when we create mathematical models of such complexity?

RAZ: And most importantly, the question Randall Munroe asked that day in class - how do you make math interesting?

MUNROE: I think that a lot of the time it's easy to get the impression that math is sort of supposed to be interesting for its own sake. But really, to me, what's exciting is the answers that the math can get you to. You know, I don't care what X is. Like, an equation doesn't mean anything until it's representing a real thing.

RAZ: By the way, after crunching the numbers, Randall and his physics students eventually calculated that it took Yoda 19.2 kilowatts of energy to lift that X-wing fighter, or about what it takes to power a small tractor. Later in the show, Randall answers more questions that I promise have never occurred to you.

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