  Waves are all around us--be it in the form of sound, electromagnetic
radiation, water waves, or earthquakes. Their study is an important basic tool
across engineering and science disciplines. Every wave solver serving the
computational study of waves meets a trade-off of two figures of merit--its
computational speed and its accuracy. Discontinuous Galerkin (DG) methods fall
on the high-accuracy end of this spectrum. Fortuitously, their computational
structure is so ideally suited to GPUs that they also achieve very high
computational speeds. In other words, the use of DG methods on GPUs
significantly lowers the cost of obtaining accurate solutions. This article
aims to give the reader an easy on-ramp to the use of this technology, based on
a sample implementation which demonstrates a highly accurate, GPU-capable,
real-time visualizing finite element solver in about 1500 lines of code.
