Denis Guedj, _The Parrot's Theorem_, Weidenfeld & Nicolson,
London, 2000.
Review by Jeffrey Shallit.
Mathematics is hot!
Or so I'd conclude from the slew of mathematically-inspired books in
the last few years. Although most people admit math was their least
favorite subject in school, they're nevertheless buying works such as
Bruce Schechter's _My Brain is Open_ (a biography of the itinerant
Hungarian mathematician Paul Erdos) and Philibert Schogt's _The Wild
Numbers_ (a novel about a mathematics professor's quest for proof).
Even Marilyn vos Savant's _The World's Most Famous Math Problem_ (a
book about the proof of Fermat's Last Theorem) sold many thousands of
copies, despite being what one mathematician called "the worst popular
book on a mathematical topic ever written".
All this literary attention is good news for mathematicians, who have
eyed the success of academic superstars in other fields, such as
Camille Paglia and Alan Dershowitz, with not a little envy. Who would
have dreamed a book about Fermat's last theorem would be a
best-seller?
But most of these books with mathematical themes don't contain much
actual mathematics. Publishers, I've been told, believe that sales are
cut in half for every equation a book contains.
Denis Guedj's _The Parrot's Theorem_, a translation of the best-selling
French novel _Le Theoreme du Perroquet_, is an exception. It doesn't
just describe mathematics, it explains it. And mathophobes beware: it
contains dozens of equations.
Guedj, a professor of the history of science at the University of
Paris, has scrambled a mystery involving a deaf boy named Max, a parrot
named Sidney, a bookseller, and the bookseller's mysterious Brazilian
friend together with a mathematics textbook instructing the reader about
geometry, algebra, and number theory.
Along the way, the reader will learn about prime numbers, Goldbach's
conjecture, the quest for the solution of the cubic equation, and the
most famous equation in mathematics.
This blend of mathematics and mystery is intriguing and intellectually
stimulating, if not entirely successful. Mystery fans will guess the
book's central puzzle with no difficulty (the title is a giveaway).
The mathematics, however, may pose a challenge for most readers. This
is definitely not a book for light reading before bedtime.
The book does contain some mathematical inaccuracies, such as defining
an an algebraic number as "a number which is the solution to a
mathematical equation". (It should be a number which is the root of
a polynomial equation with whole number coefficients.) And we learn on
one page that Lambert proved that pi is irrational (not the quotient of
two whole numbers) and on the next page that he didn't.
Nevertheless, _The Parrot's Theorem_ is an entertaining labyrinth of
mathematics and mystery. You may not get a Ph. D. in mathematics when
you finish, but you'll have a deeper appreciation for the ability of
mathematics to enchant and confound.
[Jeffrey Shallit is Professor of Computer Science at the University
of Waterloo.]