### e-the story of a number

I recently finished reading e- the story of a number by Eli Maor. It was interesting, but certainly no History Of Pi. On the other hand, it was 1048576 times better than Gregory Chaitin's Meta Math!. (On the very off chance Chaitin is reading this, at least get the title written before you start overusing exclamation marks).

For those unfamiliar, the number e is the limit as n approaches infinity of (1+1/n)

The book was a bit of a mess. At some points I thought "The Story Of Logarithms" would be a better title, and at others I thought "The Story Of Calculus" would be more suitable. I didn't learn as much about the actual number e as I had hoped to. I was hoping to learn why the number is called e. Maor addresses this. Leonard Euler gave the number it's name, but Maor draws a blank on the reasons. He says it is unlikely that the e stands for Euler, and suggests that it stands for exponent. (But that seems unlikely to me...Euler was German and exponent is an English word).

And there's not nearly enough about Euler as I would have liked. His life is not discussed in any detail until the 13th chapter (about 2/3 of the way through the book.) I did like this particular passage about the last day of his life: "On 18 September 1783 he was calculating the orbit of the newly discovered planet Uranus". OK, I probably didn't enjoy this in the way the author intended for me to.

I learned a few new things. e is important in the solution of what Maor calls the "misplaced envelope problem" (more traditionally called the hat check problem.) In this problem, someone is given the task of putting n letters into n addressed envelope. The problem is to find the probability that ALL of the letters get put in the wrong envelope. As n grows larger, the probability approaches 1/e (or approximately 37%).

I also learned that i

So there's good material, but Maor didn't do a good job of putting it together. He is certainly no Petr Beckman or John Derbyshire.

e-the story of a number is the 45th book I've read this year. I'm going to try to make it to 50 before the year is out.

For those unfamiliar, the number e is the limit as n approaches infinity of (1+1/n)

^{n}. It's approximately equal to 2.718. A good way to understand this number is to think about 1% yearly interest being compounded at smaller intervals during the year. Even if you compounded every second, you would never get a better rate than 271.8%. That's admittedly better than 1%, but it's not infinite as you would expect.The book was a bit of a mess. At some points I thought "The Story Of Logarithms" would be a better title, and at others I thought "The Story Of Calculus" would be more suitable. I didn't learn as much about the actual number e as I had hoped to. I was hoping to learn why the number is called e. Maor addresses this. Leonard Euler gave the number it's name, but Maor draws a blank on the reasons. He says it is unlikely that the e stands for Euler, and suggests that it stands for exponent. (But that seems unlikely to me...Euler was German and exponent is an English word).

And there's not nearly enough about Euler as I would have liked. His life is not discussed in any detail until the 13th chapter (about 2/3 of the way through the book.) I did like this particular passage about the last day of his life: "On 18 September 1783 he was calculating the orbit of the newly discovered planet Uranus". OK, I probably didn't enjoy this in the way the author intended for me to.

I learned a few new things. e is important in the solution of what Maor calls the "misplaced envelope problem" (more traditionally called the hat check problem.) In this problem, someone is given the task of putting n letters into n addressed envelope. The problem is to find the probability that ALL of the letters get put in the wrong envelope. As n grows larger, the probability approaches 1/e (or approximately 37%).

I also learned that i

^{i}is equal to e^{-pi/2}. I had been discussing this with Elle a couple of days earlier, and I mistakenly told her that i^{i}is equal to e^{-pi}. After reading this, I contacted Elle ASAP and corrected my error. She was very forgiving, but boy is my face red!So there's good material, but Maor didn't do a good job of putting it together. He is certainly no Petr Beckman or John Derbyshire.

e-the story of a number is the 45th book I've read this year. I'm going to try to make it to 50 before the year is out.

armrhaMan, I wish I could read 50 books a year. Maybe that'll be a goal for next year. I think History of Pi is on the top of my list for the next year.

babydoc3History Of Pi is a great item to put on your reading list. It's one of my top 10 non-fiction books. I think you also might enjoy The Education Of Henry Adams. A lot of it deals with his struggles to form a coherent theory of how the universe works (particularly in historical matters), and I thought of you a few times when I was reading it.