You actually can split up a physical simulation. Imagine you're trying to model heat diffusion through a piece of metal. You split the chunk of metal up into ma

You actually can split up a physical simulation. Imagine you're trying to model heat diffusion through a piece of metal. You split the chunk of metal up into many small pieces and model temperature in each one. Each node in your cluster is simulating the behavior of some portion of the model; at each timestep, nodes simulating chunks that border each other must swap the state of their "edges", sharing the outer edges of their own state with their neighbors. Edit: unless you meant that you can't split up a physical simulation on loosely-coupled nodes and still get good performance. Then, well, yeah.