This animation shows the density in the stellar core fluid below the shock in a three-dimensional simulation of instability of the core collapse supernova shock wave. The instability leads to the formation of two strong, counter-rotating flows. Gold depicts one flow, moving clockwise about the vertical axis. Green depicts a deeper flow moving in the opposite direction. The inner flow is capable of spinning up the neutron star left behind by the supernova, perhaps explaining the origin of pulsars. John Blondin of North Carolina State University and Anthony Mezzacappa of Oak Ridge National Laboratory developed the simulation. Kwan-Liu Ma of the University of California at Davis developed the animation..