BOOK REVIEW
A Postmodern Romance
Stuart Shieber
Turing (A Novel about Computation).
Christos H. Papadimitriou.
viii + 284 pp. MIT Press,
2003. $24.95.
Christos Papadimitriou's Turing (A Novel about Computation)
is an epistolary novel—or rather, an
e-pistolary novel,
constructed in large part from "transcripts” of
electronic messages exchanged by various characters, some of them
human beings and some computers.
The plot structure is familiar: Boy meets girl, boy loses girl, boy
gets girl. But that structure is perhaps the least important part of
the book, as it ignores the fact that the crucial character in this
novel is a computer program. This interactive tutoring program,
Turing (in
the book, the name is always rendered in a different typeface from
the rest of the text), is a simulation of Alan Mathison Turing
himself, the founder of the field of computer science and a seminal
contributor to essentially all of its major subfields. The
simulation is perfectly fluent; the program even writes in
Britishisms: maths, programme, telly, labour.
Ethel, a high-flying software guru vacationing in Corfu, mentions
the chimerical Turing
program to her new lover, Alexandros. Alexandros is an archaeologist
struggling with his current discovery, a mysterious gearbox
recovered from an ancient shipwreck near the island of Kythera.
After their fevered assignation, Ethel leaves Alexandros
heartbroken. He spends the next 200 pages working through the loss
while being educated by Turing on a
number of computer science and related topics.
The book's subtitle is apt, and the coverage of computing-related
topics is daunting. They include non-Euclidean geometry, the liar
paradox, Cantor's diagonalization proof, pipelined computer
architectures, packet switching, Turing machines, uncomputability,
the halting problem, morphogenesis by reaction-diffusion,
Arrow-Debreu economic equilibria, NP-completeness, public-key
cryptography and the Turing test. Not coincidentally, many of these
are core ideas developed by Alan Turing. As the denouement, Turing
engages in a Turing test itself: The crucial conversation
precipitating the reuniting of Ethel and Alexandros has Turing
standing in, Cyrano-like, for the male suitor. In the end, the
dangling threads all get resolved—Ethel, Alexandros, Turing, even
the Kytherian gearbox.
Perhaps the most attractive thing about the book from the point of
view of a computer scientist—and in stark contrast to the vast
majority of fiction that deals with computer-related issues—is
the quality of the discussions of computing. Typical attempts to
make concepts of computer science accessible to a lay readership
have a cringe-making quality. Papadimitriou, an acclaimed computer
scientist and a professor in the renowned computer science
department of the University of California, Berkeley, is not someone
to make the kinds of elementary mistakes that one finds in
journalistic coverage or garden-variety science fiction. This alone
is enough to make a scientist grateful. More, Papadimitriou is,
refreshingly, willing to grant the reader some intelligence; he
describes the Aegean shoreline as "so hauntingly beautiful
because its fractal dimension happens to be equal to the golden
ratio" and is willing to stop there, with no pedantic
explanations of either of the technical concepts. (Whether the claim
is true is a different matter.)
This is truly a novel of ideas, and not only ideas about computer
science. The author brings up philosophy, both ancient (more Greek
philosophers than anyone outside a philosophy department should be
able to name) and modern (Bertrand Russell); history, both distant
(Roman Empire) and recent (Edward and Mrs. Simpson), both deep
(World War II) and superficial (Edward and Mrs. Simpson); and ideas
from mathematics, economics, biology. The breadth of knowledge that
Papadimitriou displays is striking, without being overbearing; one
is left feeling that a meal with the author would be fascinating,
not tedious.
True, the writing gets a bit mawkish at times:
He pauses, he looks deeply into her eyes, then: "All I
want now is to be with you, my love. All the time. No masks, no
games.”
Jackie Collins is ventriloquized in sex-charged scenes. On the other
hand, some of the tropes seem to have come from the oeuvre of
William Gibson (the famed science-fiction novelist who coined the
term cyberspace):
"If this is true, if he can pick out clients of
relevance engines, you know what it means?” Her little face is
now full of shadows. "It means that this is runner code, Dad.
It means he has taken over the relevance engines, shredded their
smoke.”
Or, as Gibson would have it, "cracked their ice."
And, of course, there are plenty of details to quibble about.
Indeed, much of the book's afterword, which consists of 36 pages of
newsgroup postings attributed to members of a book club reading the
novel, is devoted to quibbles on one topic or another: Is the
author's presentation of the history of cryptography
"timid" in not making clear the conspiratorial role of the
U.S. National Security Agency? Did Archimedes really die at the hand
of a soldier who erased a diagram the mathematician was drawing in
the sand? Is the author too kind to the Macedonians? Not kind
enough? This "reader commentary," however, allows
Papadimitriou to provide references to the literature and to expand
on some of the technical ideas in the text without encumbering its flow.
One of my own quibbles is that Papadimitriou passes on two myths
about Alan Turing: that he predicted his eponymous test would be
passed by the year 2000, and that he viewed passing as requiring a
mere 30 percent probability of confusing the judge in the test. Both
claims are based on common misreadings of Turing's seminal paper
"Computing Machinery and Intelligence."
But such nitpicking misses the point. The plot, such as it is,
provides the excuse to present the most interesting, important and
exciting results of computer science, as well as a passel of other
ideas, in a readable and entertaining way, with a veneer of romance.
This novel is a fun read, but not a mere entertainment. It has
profundity as a side effect.