American Notes MATHEMATICS

Pi, as every schoolchild used to know, is the ratio of the circumference of a circle to its diameter. But in the electronic age, the ancient Babylonian constant -- or rather the accurate calculation of its value -- has become a symbol of computational prowess. In the 1950s the U.S. led the way, churning out estimates of pi accurate to thousands and tens of thousands of decimal places. Then the French took the lead. With the emergence of Japan's supercomputer industry in the 1980s, pi has become an almost exclusive province of the Japanese. The last world record, 201 million digits, was set on a Japanese supercomputer in 1988.

Now 3.14159 . . . is once again as American as apple pie. Or nearly so. Using U.S.-made supercomputers, two Columbia University mathematicians have established a new record: 480 million digits, a number that, if printed out linearly, would extend 600 miles. The feat was accomplished by David and Gregory Chudnovsky, Soviet emigre brothers who took jingoistic pride in beating the Japanese. "They may have faster supercomputers," says David Chudnovsky, "but they don't have our Yankee know-how."