We derive both Lagrangian and Hamiltonian mechanics as gauge theories of
Newtonian mechanics. Systematic development of the distinct symmetries of
dynamics and measurement suggest that gauge theory may be motivated as a
reconciliation of dynamics with measurement. Applying this principle to
Newton's law with the simplest measurement theory leads to Lagrangian
mechanics, while use of conformal measurement theory leads to Hamilton's
equations.Comment: 44 pages, no figures, LaTe