One Hundred Essential Things You Didn't Know You Didn't Know: Math Explains Your World

Hype rules the world. This book is promoted in a misleading way. There is nothing 'essential' about the one- hundred small math and science lessons Barrow gives us here. Ninety- nine percent of humanity will manage to get through their lives without knowing anything of what is written here.
On the other hand , for those who love Math, who care to understand the way the world works this book is a little treasure. Barrow is an extremely brilliant person and a very clear writer. He takes all kinds of problems here, and shows how mathematically we come to better understanding of them. Bridge- construction, choosing a card, demographics of the world, are among the subjects he tackles. I began to read this book and found it tremendously interesting. But again this is a work for those who like to understand latest developments in science and math. For them this should be a great read.

Scientific American listed this book as "Also Notable," and the subtitle interested me, so I got it and read it. The title makes little sense -- I didn't find any essential things I didn't know that I didn't know. But I did find a lot about how math explains things in the real world. That I liked.

In the book John Barrow collects his thoughts on 100 topics, ranging from "Why Does the Other Queue [Barrow's British] Move Faster" to "How to Push a Car." Although the substance is rather similar to John Allen Paulos's A Mathematician Reads the Newspaper, the style is quite different. In Barrow's book, each topic has a few pages each in an independent section. Paulos takes more of a chapter essay approach, with each chapter covering a broad topic and Paulos taking a rambling walk from beginning to end. Barrow writes well, and his approach works fine.

Some of the topics Barrow chooses are more interesting than others. I read them all, but did skim over some that did not quickly catch my interest. There are 100 of them, after all. For me, that was probably about 50 too many.

The main complaint I have about the book is that someone, perhaps the author or maybe an editor, decided that they had to convince the reader that each topic is important. They are not. These topics are interesting (to me, at least), but far from "essential." If you like math and physics, like me, you'll probably like the book. If you don't like math and physics, you probably won't like the book. It won't convert you.

I've just finished John D. Barrow's "100 Essential Things You Didn't Know You Didn't Know" and recommend it highly.

In some ways it's more accessible than two of his other books I've just read, "The Infinite Book" and "Cosmic Imagery".

True they have more discussion (Infinite) and pictures (Imagery) but "100 Essential" manages to present key concepts in 2 to 4 pages each AND to tie them to immediately understandable real life examples.

For example, if you had 100 people to choose from to hire, your best strategy is to interview 37 and rate and dismiss them, then hire the next person you interview who's as good or better than the highest in the first 37 (sounds strange doesn't it!).

Or: Why the fact that interest rates are non-zero is evidence for the lack of time travel to the past (wait til you read that one!).

Or: Global Village Stats

Or: The whole world in a sheet of A4 paper

True some of the 100 points are repeats of things in "Infinite" and "Imagery" - but not too many and the numbers of new topics more than make up for the occasional repeat.

Truly this is a "Pocket Barrow" worth getting and sharing with your friends when you need an evocative discussion topic or three.

+ Many short chapters = easy to pick up and read in short bursts
+ Some interesting items here and there (IMHO)
- I wouldn't say that all 100 things are directly related to math.
- Sometimes Barrow would state a subject/problem and then immediately say something like "here is the equation you use to solve it". It would have been nice to discuss the *whys* of the equation and develop more of an intuitive feel. (There are a couple of times where he does discuss the equation from an intuition standpoint, but there are a lot of missed opportunities.)
- It's hard to determine the intended audience for this book. Sometimes the text seems intended for the layman that might have a mild interest in recreational math. But I think some of the math/notation would not be understood by most people.
- I'm not sure if this would be considered a negative, but a couple of the references to the sport of cricket may be difficult for US audiences to follow (it was for me).

In summary, this book did have some "jewels in the rough" for those who like recreational mathematics, but you would probably do better to look elsewhere. This book seems more like a random collection of things that the author finds interesting but are far from "essential" as the title indicates. This book is definitely not for "brushing up" on your math skills, and I wouldn't even recommend it if you are looking for something to increase your math skills.

Professor Barrows takes a slight diversion from his recent books, by assemblying 100 precis-like mathematical topics for one' s amusement. Each topic is no greater than a couple of pages, and makes incremental reading (such as while at an airport or train/subway station) convenient. His style is easy to digest, and his introductory quotations aptly ensconces the topics to be discussed. For those wanting more background or details, most of the topics are footnoted at the back of the book.
This book is a fun read for any mathematics afficionado.