An experimentalist collects events about a physical system. A theorists builds a model to describe what patterns ofevents within a system might generate the experimentalist's data set. With hard work and luck, the two will agree!Events are handled mathematically as 4-vectors. They can be added or subtracted from another, or multiplied by ascalar. Nothing else can be done. A theorist can import very powerful tools to generate patterns, like metrics andgroup theory. Theorists in physics have been able to construct the most accurate models of nature in all of science.I hope to bring the full power of mathematics down to the level of the events themselves. This may be done byrepresenting events as the mathematical field of quaternions. All the standard tools for creating mathematical patterns- multiplication, trigonometric functions, transcendental functions, infinite series, the special functions of physics -should be available for quaternions. Now a theorist can create patterns of events with events. This may lead to a betterunification between the work of a theorist and the work of an experimentalist.