  A new theory of a (flat) spacetime gravitational interaction is presented.
This theory follows almost effortlessly from a new Lagrangian formulation of
Maxwell's theory for photons and electrons (and positrons) whose associated
Euler Lagrange equations imply the conventional Maxwell equations, but which
possesses new \textbf{\emph{bosonic}} degrees of freedom that may be associated
with a fundamental gravitational interaction. The precise character of this
gravitational interaction with photons is explicitly defined in terms of a
local U(1)-invariant Lagrangian in Eq.[\ref{Lagrangian3}].
  The new formulation of Maxwell's theory is cast on the real, eight
dimensional pseudo-Euclidean vector space defined by the split octonion
algebra, regarded as a vector space over $\mathbb{R}$, and denoted $
\mathbb{R}^{4,4} \cong M_{3,1} \oplus {}^*M_{3,1}$. (Here $M_{3,1}$ denotes
real four-dimensional Minkowski space-time and $ {}^*M_{3,1}$ denotes its dual;
$\mathbb{R}^{4,4}$ resembles the phase space of a single relativistic
particle.) This gravitational interaction is carried by a field that defines an
algebraically distinguished element of the split octonion algebra, namely, the
multiplicative unit element. We call this interaction the "unit" interaction,
since any equivalence with Newton-Einstein gravity has yet to be established.
