© Courtesy of Brookhaven National Laboratory.
The aftermath of a high-energy collision between heavy ions, such as the one shown here, is an exotic state of matter called a "quark-gluon plasma." The particles in the plasma are strongly interacting, so it is thus difficult to understand their behavior using conventional methods of calculation. The AdS/CFT duality, which links two separate theoretical descriptions of the same physics, has been used to model the outcome of collisions in the Relativistic Heavy Ion Collider at Brookhaven and has successfully predicted certain properties of the plasma, including the tiny ratio of its viscosity to its entropy. (Unit: 4)