PALO ALTO, CA ( AP) - A century old math problem, so complicated that its handwritten solution would cover the island of Manhattan, was finally cracked by an international research team working for four years. The 18 member group of mathematicians and computer scientists was convened by the American Institute of Mathematics in Palo Alto to map a theoretical object known as "Lie Group E8". Lie (pronounced "Lee") groups were invented by 19th century Norwegian mathematician, Sophus Lie, in his study of symmetrical objects, especially spheres, and differential calculus.

The E8 group, discovered in 1887, is the most complicated Lie group with 248 dimensions, long considered impossible to solve. "To say precisely what it is, is something many mathematicians can't understand," said Jeffrey Adams, the projects leader and a professor of Mathematics at the University of Maryland.

The problem's proof consists of more than 205 billion entries. When stored in a highly compressed form on a computer hard drive, the solution takes as much space as 45 days of continuous music in MP3 format. "It's like a Mount Everest of mathematical structures they've climbed now", said Brian Conret, director of the Institute.

The calculation does not have any obvious practical application, but could help advance theoretical physics and geometry, researchers said.