## Friday, January 10, 2014

### Explaining Calculus using the Up-Goer Five Text Editor

Randall Munroe writes xkcd, a series of comic strips that often involve math, technology, and science. (Sometimes not safe for work, or kids.) A few years back, he wrote a description of the Saturn Five, which he called the Up-Goer Five, using only the one thousand most commonly used words. Theo Sanderson was intrigued, and built a text editor that only allows those words. He called it 'The Up-Goer Five Text Editor.'

A friend linked to this on Facebook, asking: "Can you explain a hard idea using the ten hundred most common words?" So I decided to try to explain calculus. What I wrote seems pretty bad. My explanation from October seems much clearer. But I thought I'd share.

Will you try it with a math topic? (I'd love to see a better description of calculus.) Here are some of the words you can't use: math, slope, steepness, circle, curve, and infinity.

About calculus:Some lines are straight. Some are not. It's easy to think about how much a straight line goes up as it goes over. It's harder to think about that when the line is not straight. Two guys figured out some good ideas to help think about this around 1670. They cared because it would help people think about the world. How fast do things fall? How does light turn when it goes through round glass? How do we find the best way to do something? Their ideas also help us think about areas that don't have straight edges.

To think about these things, we need to think about something bigger than any number, about  two things closer than any number can say, and about cutting smaller parts than any number can say. Thinking about this in just right ways takes some hard thinking.