  A goal of physics is to understand the greatest possible breadth of natural
phenomena in terms of the most economical set of basic concepts. However, as
the understanding of physics has developed historically, its pedagogy and
language have not kept pace. This gap handicaps the student and the
practitioner, making it harder to learn and apply ideas that are `well
understood', and doubtless making it more difficult to see past those ideas to
new discoveries. Energy, momentum, and action are archaic concepts representing
an unnecessary level of abstraction. Viewed from a modern perspective, these
quantities correspond to wave parameters, namely temporal frequency, spatial
frequency, and phase, respectively. The main results of classical mechanics can
be concisely reproduced by considering waves in the spacetime defined by
special relativity. This approach unifies kinematics and dynamics, and
introduces inertial mass not via a definition, but rather as the real-space
effect of a reciprocal-space invariant.
