How Not to Be Wrong: The Power of Mathematical Thinking
Jordan Ellenberg
Shows how choosing a way to measure distance turns mosquitoes, markets, novels, pandemics, games, machine learning and voting maps into shapes you can reason about, and how to correct your intuitions with logic.

1 min 06 sec
Most people left geometry behind in a school classroom, along with triangles and proofs they never used again. In Shape, mathematician Jordan Ellenberg argues that it never stayed there: wherever you can say how far apart two things are, there is a geometry to study. Abraham Lincoln even credited his skill at argument to the subject, which taught him to build a case one careful step at a time.
Ellenberg’s throughline is that choosing a way to measure distance turns almost any problem into a space you can explore, where intuition gets tested and then corrected by logic. A mosquito’s final resting place, a stock option, a Russian novel, a pandemic, a game of checkers, a cat-spotting computer and a rigged election map all give way to that one move. What you get is a small kit of thinking tools: one for spotting runaway growth early, one for predicting where random wandering ends, and one for telling a fair map from a stacked one.
1 min 27 sec
By one honest measure, Los Angeles sits closer to New York than to San Francisco. That oddity points to a simple rule for seeing structure in places nobody thinks of as shapes, from film casts to card decks.
1 min 22 sec
An internet argument about drinking straws has no obvious winner, and a party balloon makes things even stranger. Working through both shows the habit of mind that geometry trains, and why a weird answer can still be right.
1 min 26 sec
A mosquito that picks its direction at random every day might seem free to end up anywhere. The arithmetic of its wandering says otherwise, and a French mathematician found the same pull at work in financial markets.
1 min 20 sec
A Russian mathematician imagined an insect that remembers yesterday, then turned the same idea on great works of literature. The numbers he found suggest every writer leaves a statistical fingerprint, whether they know it or not.
1 min 44 sec
In early 2020, a death count that seemed small became a daily toll within a week. The same math that explains that jump also explains why the worst forecasts never came true, and it applies to rumors too.
1 min 29 sec
Two players, a few piles of stones, and one of them is beaten before touching a single stone. A simple drawing explains why, and the same drawing has already settled the outcome of perfectly played checkers.
1 min 29 sec
A climber with no map and a computer staring at cat photos solve their problems the same way. Seeing the method clearly shows what learning means for a machine: steadily tweaking its approach until it is wrong as seldom as possible.
2 min 00 sec
One party swept a state’s top offices and still could not dent the other side’s grip on its legislature. Thousands of computer-drawn maps reveal how unusual that result really was, and offer a test of fairness anyone can borrow.
1 min 05 sec
Shape turns out to be a book about how to think, with mathematics as the practice ground. Once you can say how far apart two things are, you have a space with rules. The reasoning that predicts where a mosquito dies can then price a bet, fingerprint a novel, warn of a surging virus, settle checkers, teach a computer what a cat is and expose a stacked map.
These tools work well beyond mathematics. When a comparison feels obvious, ask which metric you are using and whether another would tell a different story. When your gut answers fast, write out the logic and stay open to a strange result, like the balloon’s negative one hole. When something spreads, watch how many new people each case reaches. And when someone calls an outcome fair, picture the whole crowd of outcomes chance could have produced, and see where the real one stands.
Lincoln sharpened his arguments by working through proofs. Starting from a hunch and correcting it one careful step at a time is still the most useful thing geometry has to teach.
Most people remember geometry as triangles and proofs from a school classroom. Jordan Ellenberg, a mathematician at the University of Wisconsin-Madison, argues that it reaches much further. Anywhere you can say how far apart two things are, you have a geometry, and that covers cities, film actors, shuffled decks of cards and much else. From that starting point, Ellenberg shows the same reasoning at work in very different places. Ronald Ross's mosquitoes lead to the random walk and to Louis Bachelier's work on stock options. Andrei Markov's chains turn up in the vowels of Russian novels. Exponential growth and the R0 figure explain how COVID-19 and rumors spread. Tree diagrams can settle games like Nim and checkers before anyone moves, and gradient descent teaches computers to recognize cats. The book ends in Wisconsin, where a Republican-drawn map kept that party's assembly majority even as Democrats won the state's top races, and where thousands of computer-drawn maps showed how extreme the 2012 assembly result was. Readers come away with a set of portable thinking tools. Above all, they get Ellenberg's core habit: start from intuition, then let logic correct it.
Professionals who left math behind at school and want sharper tools for judging data, growth and risk.
Curious readers wondering how pandemics, markets and machine learning actually work.
Citizens who suspect election maps are rigged and want a fair way to test it.
Jordan Ellenberg is an American mathematician on the faculty of the University of Wisconsin-Madison, where his research covers number theory and arithmetic geometry. He holds a doctorate in mathematics from Harvard and a master of fine arts in creative writing from Johns Hopkins. He wrote the Slate column Do the Math, and his articles have run in the New York Times, the Washington Post, the Wall Street Journal and the Boston Globe. His other books include How Not to Be Wrong and the novel Grasshopper King.
Jordan Ellenberg
Listeners find the book highly educational and expertly written, with one listener drawing attention to the useful diagrams and descriptions. Furthermore, they like how the author presents advanced math in an accessible way, with one listener noting an ingenious example of mathematical proof in Chapter 5. The work is also praised for its humorous tone and extensive coverage, as one listener describes how it bridges the gap between geometry and algebra. Yet, listeners are split on the prose; some consider it very easy to read, while others find it difficult to track.
Jordan Ellenberg has this incredible knack for making you see the world through a completely different lens. This isn't the dusty, formula-heavy geometry you suffered through in ninth grade with your braces and pop-star crushes. Instead, Ellenberg shows how shapes and spatial logic underpin everything from the spread of a pandemic to the way computers learn to play Go. The chapter on the geometry of gerrymandering was a revelation for me, specifically because I never realized how mathematical fairness could be so complex. To be fair, he does wander off into the weeds occasionally, but his charismatic writing keeps things engaging. If you want to understand how the hidden structures of our world actually function, this is essential reading. It manages to bridge the gap between abstract algebra and our daily lives with genuine humor and wit.
Show moreThe way Ellenberg bridges the gap between abstract algebra and the physical world is nothing short of masterful. I was particularly gripped by his explanation of the SIR model during the pandemic discussion; it turned a terrifying reality into a logical puzzle. This book is a far cry from the laborious proofs and QEDs that most of us remember from high school. Each chapter introduces a new way of thinking, whether it’s through game theory or the geometry of representation in democracy. Not gonna lie, some of the math toward the end gets pretty heavy, especially regarding eigenvectors and neural networks. But even if you don't grasp every single technical detail, the overarching narrative about human curiosity is beautiful. It is an informative and accessible exploration of a subject I thought I hated. I highly recommend it to anyone who likes their science with a side of humor.
Show moreAfter hearing so many good things about this, I was thrilled to find that the reality lived up to the hype. Ellenberg argues that geometry isn't just a school subject; it is a way of measuring and explaining the world we live in. His deep dive into the issue of fairness in voting districts was eye-opening and showed how math can solve real-world political problems. I loved the way he wove together history, philosophy, and high-level statistics into something that actually felt readable. Some of the meandering chapters actually felt like a conversation with a very smart friend who keeps finding cool things to tell you. It is a big, ambitious book that makes you feel smarter for having read it. Even the sections that were a bit over my head were fascinating enough to keep me engaged. This is definitely a five-star read for anyone who enjoys popular science.
Show moreAs someone who usually finds math textbooks incredibly dry, I was surprised by how much this book pulled me in. Ellenberg uses geometry to explain some of the most pressing scientific and philosophical problems we face today. I particularly enjoyed the section on how computers have been taught to play chess and the inherent difficulties in machine learning. The diagrams are actually helpful rather than being just filler, which I appreciated. Truth is, I did get lost during some of the more technical explanations of the uncertainty principle and random walks. Despite those moments of confusion, the author’s enthusiasm for the subject is infectious and kept me moving forward. It’s a broad, ambitious work that succeeds more often than it fails. Definitely worth your time if you enjoyed his previous work.
Show moreFinally got around to reading this, and I have to say, Ellenberg’s wit is what keeps the pages turning. He has a way of phrasing things—like his comments on Thomas Hobbes—that made me laugh out loud in a book about math. The book does an excellent job of showing that geometry isn't just about triangles, but about how things are near each other and how they connect. I was especially impressed by the explanation of the mosquito’s random walk, even if it did go on for a few pages too many. Personally, I think this book is a bit less polished than 'How Not to Be Wrong,' but it still offers a lot of value. The clever examples of mathematical proof in Chapter 5 were a highlight for me. It’s a great choice for anyone looking to broaden their scientific horizons without feeling like they're back in a classroom.
Show moreWhile I absolutely loved 'How Not to Be Wrong', this follow-up felt like it needed a much firmer editorial hand. Ellenberg is a brilliant communicator, but this book feels a bit like a collection of late-night brainstorms rather than a cohesive narrative. One moment you are learning about Euclid, and the next you are plunged into the deep end of eigenvalues and page rank. Frankly, the transition between topics can be jarring and the pacing feels inconsistent throughout the middle sections. Some parts, like the discussion on the topology of straws and pants, are genuinely delightful and easy to follow. However, other chapters, especially the deep dive into US political redistricting, go on for far too long. It is a dense 400-plus pages that might leave casual readers feeling slightly exhausted by the end.
Show morePicking this up after reading Strogatz’s 'Infinite Powers' was an interesting experience in contrasts. While Strogatz guides you gently through calculus, Ellenberg takes you on a wild, sometimes confusing ride through the entire landscape of modern geometry. I found the 'number of holes in a straw' debate to be a funny and approachable way to introduce topology. However, the author seems to think that absolutely everything is geometry, which leads to some very long-winded sections. In my experience, the chapters on probability felt a bit laboured compared to the more visual elements of the book. The section on Abraham Lincoln’s obsession with Euclid was fascinating, yet it felt disconnected from the modern technical bits. It's a bit of a doorstop, and I think a shorter, more focused version would have been more effective for laypeople.
Show moreEver wonder how many holes are actually in a straw? That is just one of the many quirky questions Jordan Ellenberg tackles in this massive book about geometry. It is clear that the author is a charismatic writer who truly loves his field, but I found the structure a bit too rambling for my taste. One chapter jumps from Fibonacci numbers to stocks and then suddenly into the uncertainty principle without much of a breather. For an audiobook listener like me, these quick shifts made it very easy to lose the thread of the argument. I did find the discussion on gerrymandering incredibly detailed, perhaps a bit too detailed for anyone not obsessed with US politics. It’s an interesting read for sure, but be prepared for a lot of tangents that don't always feel necessary. I might need a second pass to truly absorb everything.
Show moreMaybe I’m just not a 'math person,' but I found large sections of this book nearly impossible to get through. The description promised a look at how geometry explains the world, but it felt more like a disorganized history lecture. There are so many names and dates thrown at you that it becomes difficult to keep track of the actual mathematical concepts. For example, the extended discussion on irrational numbers like pi and phi seemed to meander without a clear point or payoff. I was hoping for something as structured as Strogatz’s 'Infinite Powers,' where each chapter builds on the last. Instead, this felt like jumping into a series of vaguely connected essays. It’s certainly well-written in terms of prose, but the lack of focus made it a chore to finish.
Show moreLook, I appreciate the author's passion for the subject, but this book is a bit of a doorstop and quite unfocused. I struggled significantly with the middle section, which seemed to dwell on the history of certain mathematicians for ages without explaining the concepts clearly. The discussion on eigenvalues was particularly opaque to me, and I felt like I needed a degree in physics to understand the connection to the uncertainty principle. To be fair, there are some gems here, like the section on computer programming and the game of Go, which were quite interesting. However, the overall experience felt like wading through a collection of brainstormed ideas that hadn't been properly woven together. If you aren't already a math enthusiast, you might find yourself skimming a lot of the denser material. It just didn't click for me.
Show moreEllenberg argues that geometry applies wherever you can define a distance between two things. Choose a metric, and cities, actors, card decks, stock prices, languages, pandemics, games and voting maps all become spaces with their own shape. Inside those spaces, the geometric habit of starting from intuition and correcting it with logic leads to better answers, from how many holes a straw has to whether an election map was gerrymandered.
Using topology, Ellenberg concludes that a straw has one hole. Shorten it until it becomes a flat ring between two circles, called an annulus, and the single hole is clear. Pants, shortened the same way, have two. He then shows that an inflated balloon must have negative one holes, since poking a hole in it leaves a disk with none.
Ronald Ross and Hilda Hudson showed that pandemics grow as geometric progressions, which look slow and then explode. Early COVID-19 deaths in the US followed this pattern. But growth slows as a virus runs out of new people, which is where R0 matters: above one an outbreak spreads, below one it fades. Ellenberg notes that rumors spread by the same rules.
Ellenberg describes how Wisconsin Republicans used software in 2011 to draw districts that kept their wasted votes low. He discusses the efficiency gap as one imperfect test. He prefers ensembles of random, legal maps: Duke University professors built 19,184 maps of Wisconsin and found that the actual 2012 result of 60 to 39 was an extreme outlier compared with the most common outcome of 55 seats.
Ask what metric sits behind any comparison you make. Test gut reactions by writing the logic out step by step. For anything spreading, track how many new people each case reaches. Before turn-based contests, reason back from the possible endings. And to judge fairness, compare an outcome with the full range that chance could have produced, as the ensemble method does for election maps.
J. Craig Venter
Carl Zimmer
Bill Bryson
Jeff Hawkins
Lisa Kaltenegger
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