Smashing polarized protons to uncover spin and other secrets

If you want to unravel the secrets of proton spin, put a "twist" in your colliding proton beams. This technique, tried and perfected at the Relativistic Heavy Ion Collider (RHIC)--a particle collider and U.S. Department of Energy Office of Science User Facility at Brookhaven National Laboratory--orients the colliding protons' spins in a particular direction, somewhat like tiny bar magnets with their North poles all pointing up.