  In previous papers we have shown how Schrodinger's equation which includes an
electromagnetic field interaction can be deduced from a fluid dynamical
Lagrangian of a charged potential flow that interacts with an electromagnetic
field. The quantum behaviour was derived from Fisher information terms which
were added to the classical Lagrangian. It was thus shown that a quantum
mechanical system is drived by information and not only electromagnetic fields.
This program was applied also to Pauli's equations by removing the restriction
of potential flow and using the Clebsch formalism. Although the analysis was
quite successful there were still terms that did not admit interpretation, some
of them can be easily traced to the relativistic Dirac theory. Here we repeat
the analysis for a relativistic flow, pointing to a new approach for deriving
relativistic quantum mechanics.
