ABSTRACT

The propagation of a wave in 1-d, ψ(t, x), is governed by local dynamics in which the instantaneous acceleration depends on the local curvature of the wave form, i.e.,

a ∝ ∂ 2ψ

∂x2 .

Identifying the acceleration as a = ∂ 2ψ ∂t2 , and realising that the wave speed [squared] is the

sole dimensional parameter extant which can fulfill the roˆle of proportionality constant, one obtains the canonical form of the wave equation:

0 = ∂2 ψ

∂x2 − 1 c2

∂2 ψ

∂t2 .