a list compiled by Alex Kasman (College of Charleston)

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Sophie's Diary (2004)
Dora Musielak
Highly Rated!

Sophie Germain famously studied mathematics at night by candlelight despite her parents' insistence that she give up this unfeminine discipline. She then went on to become one of the great mathematician's of the 18th century, making important contributions to number theory as well as shattering myths about the mathematical inabilities of her gender.

This is such an inspiring true story that it is quite surprising that Sophie's Diary appears to be the first time anyone has tried to fill in the personal details in a fictionalized first person account. I suspect that this book, which contains detailed descriptions of the events of the French revolution as well as a good deal of mathematics, was written specifically to motivate mathematically talented girls to study and pursue careers in mathematics. (The description of the author indicates that she won a mathematics contest at age six and went on to study aerospace engineering.)

You can read more about this work at other websites such as:

I do hope that this book can inspire some future mathematicians, especially girls like Sophie who have to battle sexism to follow their avocation. Certainly, the emotional aspects of the true story combined with the first person account seem like a winning combination. As Judy Holdener says in her MAA review: "The author is successful in capturing both the passion and the frustration commonly felt by mathematicians."

However, I am a bit worried by possible confusion caused by some ambiguous or misleading mathematical statements. For instance, when discussing the number π, Sophie writes:

(quoted from Sophie's Diary)

Now, mathematicians write π=3.14159.... the dots after the number nine means that the exact value of π is still unknown. One can continue refining the calculation, thus getting more digits on the right side of the decimal point, but so far nobody knows how many more.

Perhaps it is arguing semantics to wonder about her description "the exact value is still unknown". (I would say the exact value is known, but cannot be written in finite decimal form.) But, her suggestion that it is unknown how many digits are needed is a bit more troubling. It was known since 1761 (before the date on Sophie's diary entry) that π is an irrational number...and in fact she says so herself in the book. But then, we know that its decimal expansion is infinite. (In fact, it is really easy to see that any number with a finite decimal expansion is of the form n/10m for some integers n and m...just multiply by 10 until the decimal point moves all the way to the end! So, the only numbers with finite decimal expansions are a special subset of rational numbers.) It is not clear to me whether the author is confused about this point or whether it is intended to demonstrate Sophie's mathematical innocence, but it just gets worse later. After a few entries on other subjects, she says:

(quoted from Sophie's Diary)

The number π is fascinating. I know that 22/7 is a good approximation to its value, and 353/113 is a much better one. But there is no exact value since π=3.14159.... Thus, probably the number expansion on the right side of the decimal point is infinite. Maybe it is infinite because the circumference of the circle is actually an infinite number itself. This is what I think: since π is equal to the ratio of the circumference to the diameter of a circle, C/D and the circumference C is the length of the line that represents the circle and this length does not have a beginning or an end, consequently its value must be infinite.

I imagine that when she says "there is no exact value", she means "there is no exact representation of π as a ratio of whole numbers". (This might be how someone would indicate that in a diary entry for brevity, but it may not be sufficiently clear for an educational book.) Again, she repeats the strange idea that π might have only finitely many digits in its decimal expansion. The final part about the circumference being infinite is also a bit strange. I can see how this is poetic, and probably is supposed to sound like the imagination of a young girl. Of course, the circumference of a circle is finite, but since a circle has no end you can go around it infinitely many times. Poetic, but the suggestion that this is somehow connected to the infinite length of the decimal expansion of π is far from the sort of rigorous logical thinking that I imagine a mathematician as successful as Germain must have been good at.

Contributed by Anonymous

This is a wonderful book, one of its kind, and it'd be a must read book for students and instructors interested in this subject, as well as for anyone trying to encourage young women into science and mathematics. This is a book to buy for yourself and then buy ten more copies to give as gifts to your friends.

Contributed by Reiner Hammer

This is not really a biography, but a work of literature that both contrasts and amalgamates several types of worlds so vastly different that I had never thought they could be combined: the world of thoughts of a young girl that grows up and evolves mentally, the curiosity and persistency at which she explores the world of mathematics, life in historical Paris, and the extraordinary situation due to the revolution. It reminds me of coming into a kitchen, with only a few uncommon ingredients left, and facing the challenge to prepare a meal out of these ingredients that does not only look interesting, but is even tasty. Indeed a fascinating melange!

Contributed by B Lynn

This book is an obvious take on other 'diary' books in the literature. In addition there is a gross 'disconnect' between the level of mathematics in the book and the aim of the author which was obviously to inspire and inform young girls. What comes out from reading this book is the author's egotistical and obvious need for recognition and approval in the form of a young adult read. It is trite to sum up.

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Works Similar to Sophie's Diary
According to my `secret formula', the following works of mathematical fiction are similar to this one:
  1. Prince of Mathematics: Carl Friedrich Gauss by Margaret B.W. Tent
  2. Carry On, Mr. Bowditch by Jean Lee Latham
  3. Murder, She Conjectured by Alex Kasman
  4. The Romance of Mathematics: Being the Original Researches of a Lady Professor of Girtham College... by Peter Hampson Ditchfield
  5. The Simpsons: Girls Just Want to Have Sums by Matt Selman
  6. Sophie Simon Solves them All by Lisa Graff
  7. Against the Odds by Martin Gardner
  8. Stella Maris by Cormac McCarthy
  9. The Number Devil [Der Zahlenteufel] by Hans Magnus Enzensberger
  10. The Mathematician's Shiva by Stuart Rojstaczer
Ratings for Sophie's Diary:
RatingsHave you seen/read this work of mathematical fiction? Then click here to enter your own votes on its mathematical content and literary quality or send me comments to post on this Webpage.
Mathematical Content:
4.6/5 (5 votes)
Literary Quality:
3.6/5 (5 votes)

GenreHistorical Fiction, Didactic, Children's Literature,
MotifProdigies, Real Mathematicians, Female Mathematicians, Math Education,
TopicAlgebra/Arithmetic/Number Theory, Analysis/Calculus/Differential, Real Mathematics,

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Exciting News: The 1,600th entry was recently added to this database of mathematical fiction! Also, for those of you interested in non-fictional math books let me (shamelessly) plug the recent release of the second edition of my soliton theory textbook.

(Maintained by Alex Kasman, College of Charleston)