Two gold atoms stripped of their electrons and smashed together at nearly the speed of light disintegrate into quarks (white) and gluons (green), then coalesce into clusters (red). The clumps then break apart into kaons, pions, and other particles in these animation stills spanning about 10-22 of a second. That's the anticipated scene inside Brookhaven National Lab's Relativistic Heavy Ion Collider (RHIC), a new accelerator coming online this fall that will attempt to simulate the hot, dense quark-gluon plasma that existed just after the big bang (Science, 20 August, p. 1194). Brookhaven physicist Ronald Longacre says the animations are in part for the public, but they're also "a good debugging tool" for finding glitches in the computer code for modeling the reactions: "It's amazing how good your eye is at seeing patterns" that don't jibe with theory. Follow the links to see more simulations by RHIC scientists and outside groups.