Terminology is an occupational hazard of philanthropy. I’ve found this is especially true if you work in an area like health. It is not unusual to be discussing the latest disease research and hear someone throw around words like serum and in vitro (and more complicated ones). Over the years I’ve gotten comfortable with all the terms, but at first I had to keep reminding myself: Serum just means blood without the red and white cells. In vitro just means “in the glass”—as in test tubes. I still go through that process today with different subjects.

So it was fun to read Randall Munroe’s new book, Thing Explainer: Complicated Stuff in Simple Words, which will come out on November 24. Munroe sets out to explain various subjects—from how smartphones work to what the U.S. Constitution says—without any complicated terms. Instead he draws blueprint-style diagrams and annotates them using only the 1,000 most common words in the English language. A nuclear reactor is a “heavy metal power building.” A dishwasher is a “box that cleans food holders.” The periodic table is “the pieces everything is made of.”

It is a brilliant concept. If you can’t explain something simply, you don’t really understand it. And Randall Munroe is the perfect guy to take on a project like this. He’s a former NASA robotics expert who now makes a living drawing the geeky comic strip XKCD and writing books. (I reviewed his What If? earlier this year.) Munroe reminds me of Sal Khan of Khan Academy, or the novelist and Crash Course host John Green. All three are polymaths who not only know a lot but are also good at breaking things down for other people.

Thing Explainer may use a limited vocabulary, but it is filled with helpful explanations and drawings. Have you ever wondered why frozen food defrosts unevenly in a microwave oven (or, as Munroe calls it, a “food-heating radio box”)? Munroe writes: “When you put iced food in a radio box, after a while, parts of it start to turn to water. But since radio boxes are really good at heating water, those parts start to get hot really fast. They can even get so hot they start turning to air—before all the ice is even gone!”

If you know Munroe’s previous work, it will come as no surprise that parts of Thing Explainer are laugh-out-loud funny. Here for example is what he says about the business end of a Saturn V rocket (“U.S. Space Team’s Up Goer Five”): “Lots of fire comes out here. This end should point toward the ground if you want to go to space. If it starts pointing toward space you are having a bad problem, and you will not go to space today.”

Or, his take on the 18th amendment to the U.S. Constitution: “Let’s get rid of beer and wine.” And then the 21st: “Never mind about getting rid of beer and wine.”

If I have a criticism of Thing Explainer, it’s that the clever concept sometimes gets in the way of clarity. Occasionally I found myself wishing that Munroe had allowed himself a few more terms—“Mars” instead of “red world,” or “helium” instead of “funny voice air.”

Of course, that would defeat the purpose of the book. And Munroe himself is aware of the tension. In “Page Before the Book Starts”—a.k.a. the introduction—he acknowledges that some terminology is inescapable. “To really learn about things, you need help from other people, and if you want to understand those people, you need to know what they mean by the words they use. You also need to know what things are called so you can ask questions about them. But there are lots of other books that explain what things are called. This book explains what they do.”

And it does that beautifully. Thing Explainer is filled with cool basic knowledge about how the world works. If one of Munroe’s drawings inspires you to go learn more about a subject—including a few extra terms—then he will have done his job. He has written a wonderful guide for curious minds.