Summary form only given. In this virtual-reality art installation - a mathematical play space - the viewer-participant creates an immersive visual and sonic experience. It is based on the mathematical and physical simulation of over one million particles with momentum and elastic reflection in an environment with gravity. The final scene has a realistic rendering of water with reflections and lighting based on spherical harmonics. Sound components are triggered and modified by the user and particle interaction. The application was originally developed using a CUDA particle system running within Thumb, a virtual-reality framework developed by Robert Kooima. It is now being ported to CalVR, developed by researchers at the California Institute for Telecommunications and Information Technology (Calit2) Qualcomm Institute at University of California, San Diego.