(This is a copy of an article that appeared in the NY Times on
August 10, 2002)
Edsger Dijkstra, 72, Physicist Who Shaped Computer Era, Dies
By JOHN MARKOFF
Edsger Wybe Dijkstra, whose contributions to the mathematical
logic that underlies computer programs and operating systems make
him one of the intellectual giants of the field, died on Monday
at his home in Nuenen, the Netherlands. He was 72.
The cause of death was cancer, said officials at the University
of Texas, where Dr. Dijkstra held the Schlumberger centennial
chair in computer sciences from 1984 to 1999, when he retired.
Dr. Dijkstra is best known for his shortest-path algorithm, a
method for finding the most direct route on a graph or map, and
for his work as the co-designer of the first version of Algol 60,
a programming language that represented one of the first compiler
programs that translates human instructions.
The shortest-path algorithm, which is now widely used in global
positioning systems and travel planning, came to him one morning
in 1956 as he sat sipping coffee on the terrace of an Amsterdam
cafe.
It took him three years to publish the method, which is now known
simply as Dijkstra's algorithm. At the time, he said, algorithms
were hardly considered a scientific topic.
Of even greater importance was his solution to what he originally
called the dining quintuple problem, but which later became known
as the dining philosophers' problem.
He conceived of the problem faced by five philosophers sitting
around a table, each with a bowl of rice and a single chopstick.
Because eating requires two chopsticks, the challenge was to find
an equitable method that would permit all of those at the table
to eat without having anyone starve or having the entire table
face deadlock. Dijkstra's original solution ensured that each
diner took turns using a pair of chopsticks.
The problem has applicability to both computer operating systems
and to network design.
Several years after Dr. Dijkstra solved the problem, he was
surprised to learn that the Massachusetts Institute of Technology
designers of the pioneering Multics operating system had not
grappled successfully with the issue of deadlock. The consequence
was that on occasion their system would abruptly halt.
"You can hardly blame M.I.T. for not taking notice of an obscure
computer scientist in a small town in the Netherlands," he was
quoted as saying in "Out Of Their Minds: The Lives and
Discoveries of 15 Great Computer Scientists."
Dr. Dijkstra, an advocate of an approach known as structured
programming, wrote a short research note in the March 1968
edition of the journal Communications of the ACM that became
legendary. Titled "The GO TO Considered Harmful," it argued
against the complexity of a feature in programming languages like
Fortran and Basic that permitted programmers to write convoluted
programs that jump around haphazardly.
A theoretical physicist by training, early in his career he
observed that many problems required extensive calculation and so
in the early 1950's he taught himself how to program.
In March 1952 he took a part-time job at the Mathematical Center
in Amsterdam, immersing himself in the challenges of instructing
the primitive computers of the era.
When he married in 1957, the Dutch marriage rites required that
he state his profession and he attempted to say he was a
programmer. The municipal authorities in Amsterdam did not accept
his answer on the ground that there was no such profession. As a
result, his marriage certificate described his profession as
"theoretical physicist."
He was born May 11, 1930, in Rotterdam, the Netherlands. His
father was a chemist and his mother was a mathematician. In 1942,
at 12, Dr. Dijkstra entered an elite high school where he studied
classical Greek and Latin, French, German, English, biology,
mathematics, physics and chemistry. During the German occupation
his parents sent him away for a brief period to the countryside.
He earned degrees in mathematics and theoretical physics from the
University of Leyden and a Ph.D. in computing science from the
University of Amsterdam.
He worked as a programmer at the Mathematical Center from 1952 to
1962, taught mathematics at Eindhoven University of Technology
from 1962 to 1984 and was a research fellow at the Burroughs
Corporation from 1973 to 1984.
Dr. Dijkstra was the recipient of many awards, notably the
Association for Computing Machinery's prestigious Turing Award in
1972.
He is survived by his wife of more than 40 years, Maria C. Debets
Dijkstra, who is known as Ria; three children, Marcus, Femke and
the computer scientist Rutger M. Dijkstra; and by two
grandchildren.
Throughout Dr. Dijkstra's career, his work was characterized by
elegance and economy. His love affair with simplicity came at an
early age and under his mother's guidance. He once said he had
asked his mother whether mathematics was a difficult topic. She
replied that he must learn all the formulas and that furthermore
if he required more than five lines to prove something, he was on
the wrong track.