“How many dimensions space has could all be a matter of perspective. In a school of thought that teaches the existence of extra dimensions, Juan Maldacena may at first sound a little out of place. String theory is physicists’ still-tentative strategy for reconciling Einstein’s theory of gravitation with quantum physics. Its premise is that the subatomic particles that roam our three-dimensional world are really infinitesimally thin strings vibrating in nine dimensions. According to Maldacena, however, the key to understanding string theory is not to add more dimensions but to cut their number down.
But, the most important fallout from Maldacena’s intuition has probably been on the field of string theory itself. His work has offered physicists hope that they can make the string idea rigorous by tracing its roots to ordinary quantum physics. Maldacena’s conjecture has energized string theory advocates, occupying the center of a confluence of ideas coming from several branches of physics. “It’s the most incredible discovery in theoretical physics in the last 20 years,” says Harvard University’s Nima Arkani-Hamed. ”
(see also Mobius Transformations)