NEW BRUNSWICK — Order and reason are a mathematician's tools. In the hands of a very select few, however, those tools can transform an abstract discipline into art.

That, in large part, is why the Norwegian Academy of Science and Letters announced Wednesday that Endre Szemerédi, a 71-year-old Rutgers professor, had won the 2012 Abel Prize, the unofficial Nobel Prize in mathematics.

"I had no idea what was going on," Szemerédi said by phone from his native Hungary, where he was celebrating with his family. "I was very happy."

In an academic field rife with competitive jealousies, Szemerédi is uncharacteristically humble.

"It is not my own personal achievement," he said, "but recognition for this field of mathematics and Hungarian mathematicians," that gave him the most pleasure.

Michael Littman, chairman of Rutgers’ computer science department, in which Szemerédi teaches part of the year, said he is not surprised by his colleague’s humility.

"Mathematicians are people, too," Littman said. "Some are arrogant and obnoxious. Some are truly humane. (Szemerédi) is a sweet, sweet man. He has these warm smiling eyes, a nice calm way about him. He’s very magnanimous, very generous. He doesn’t think he’s the only one who works (in this field) in the world."

Mathematics, however, was hardly Szemerédi’s world growing up.

"In high school, I never studied it," he said. "My father wanted me to be a doctor."

The truth of the matter, Szemerédi says, is that he had the good fortune to be born short.

"The tallest guy in class, he was my friend. He was really interested in mathematics. I always listened to him because he was tall."

But not right away. After a disaffected Szemerédi finished medical school, he worked for two years in a factory in Hungary, and happened to run into his old high school friend, who had become a physicist. Eventually, so did Szemerédi and it was physics that led him into mathematics.

Szemerédi’s field is discrete mathematics, specifically combinatorics, which is the science of number sequences or arithmetical progressions. For example, a sequence with a "length" of five and a "space" of two between each number, and which begins at 3, is the arithmetical progression: 3, 5, 7, 9, 11.

In 1975, then in his mid-30s, Szemerédi proved that arithmetical progressions of any length — five, 10, 10,000, etc. — can be found in any positive sequence of integers.

"Endre didn’t find all the patterns," Littman said. He didn’t need to, because "he discovered the principle by which it had to be true."

That principle has inspired a generation of mathematicians in their own work and resulted in new theorems and proofs, all of which credit Szemerédi’s initial breakthrough.

Although it’s been more than 35 years since his seminal discovery, the seputagenerian is not one to rest on his laurels, according to his friends.

"People think (mathematics) is a young man’s game and once past a certain age you don’t come up with any good ideas," said former Rutgers mathematician Michael Capalbo, who collaborated with Szemerédi a dozen years ago. "I can tell you he had a lot of ideas."

Combinatorics, adds Capalbo, was not a "hot" field when Szemerédi entered into it in the late 1960s and 70s, but it has become hot in the past two decades. The applications are also myriad, from understanding social networking to optimizing airplane routes to designing underground infrastructure.

A couple of years ago, Littman, who created one of the first computer programs for solving crossword puzzles, stopped Szemerédi to ask him about a nagging combinatorics problem that involved the "labelling" of New Jersey roads.

"There are all these roads like Bernardsville Road, that will take you to Bernardsvile, or Mendham Road that will take you to Mendham," Littman said. "I wanted to know whether, given any possible graph (of roads) can you label the roads with the cities they’re going to end up in? He looked at me really quietly, and then he laughed."

A day later, however, Szemerédi stopped Littman.

"Your question was really easy," the mathematician said to the computer scientist. "It follows directly from Eulerian paths. You should be able to do the rest."

Littman understood the reference to the 18th century Swiss mathematician Leonhard Euler, but he’s never gotten around to finishing the proof.

As for Szemerédi, his main problem right now will be how to spend the $1 million award that comes with the Abel Prize, which he will pick up in Oslo, Norway, in May. In the meantime, he continues to accept congratulations from friends and colleagues around the world.

As to whether that very tall high school friend, who sent him on his life’s path, would be jealous, Szemerédi answered with a laugh, "He’s still much taller."

Related coverage:

• Rutgers professor wins prestigious Abel Prize, with $1 million in cash