  Recent work on the history of General Relativity by Renn, Sauer, Janssen et
al. shows that Einstein found his field equations partly by a physical strategy
including the Newtonian limit, the electromagnetic analogy, and energy
conservation. Such themes are similar to those later used by particle
physicists. How do Einstein's physical strategy and the particle physics
derivations compare? What energy-momentum complex(es) did he use and why? Did
Einstein tie conservation to symmetries, and if so, to which? Einstein used an
identity from his assumed linear coordinate covariance x'= Mx to relate it to
the canonical tensor. Usually he avoided using matter Euler-Lagrange equations
and so was not well positioned to use or reinvent the Herglotz-Mie-Born
understanding that the canonical tensor was conserved due to translation
symmetries, a result with roots in Lagrange, Hamilton and Jacobi. Whereas Mie
and Born were concerned about the canonical tensor's asymmetry, Einstein did
not need to worry because his Entwurf Lagrangian is modeled not so much on
Maxwell's theory as on a scalar theory. As a result, it also has 3 ghosts,
failing a 1920s-30s a priori particle physics stability test with antecedents
in Lagrange's and Dirichlet's stability work.
  This critique of the Entwurf theory can be compared with Einstein's 1915
critique of his Entwurf theory for not admitting rotating coordinates and not
getting Mercury's perihelion right.
  Particle physics also can be useful in the historiography of gravity and
space-time. This topic can be a useful case study in the history of science on
recently reconsidered questions of presentism, whiggism and the like.
