The Wave Equation with Computable Initial Data Whose Unique Solution Is Nowhere Computable

We give a rough statement of the main result. Let D be a compact subset of ℝ3× ℝ. The propagation u(x, y, z, t) of a wave can be noncomputable in any neighborhood of any point of D even though the initial conditions which determine the wave propagation uniquely are computable. A precise statement of the result appears below.