Two-dimensional fluid vortexes attract, swirling and merging with their partners in a turbulent ballet. This natural behavior influences phenomena ranging from weather patterns in the atmosphere to the performance of nuclear fusion devices. Advanced numerical algorithms and high-performance supercomputers allow for turbulence simulations of unprecedented detail. This snapshot catches the vortexes in the act. Originally entirely separated, the two vortex centers (dark red) have sent out spiral bands and shock waves throughout the background fluid as they've circled each other and combined. If left alone long enough, the two will complete their dance as a single, larger vortex.