  The generation of magnetic field in an electrically conducting fluid
generally involves the complicated nonlinear interaction of flow turbulence,
rotation and field. This dynamo process is of great importance in geophysics,
planetary science and astrophysics, since magnetic fields are known to play a
key role in the dynamics of these systems. This paper gives an introduction to
dynamo theory for the fluid dynamicist. It proceeds by laying the groundwork,
introducing the equations and techniques that are at the heart of dynamo
theory, before presenting some simple dynamo solutions. The problems currently
exercising dynamo theorists are then introduced, along with the attempts to
make progress. The paper concludes with the argument that progress in dynamo
theory will be made in the future by utilising and advancing some of the
current breakthroughs in neutral fluid turbulence such as those in transition,
self-sustaining processes, turbulence/mean-flow interaction, statistical
methods and maintenance and loss of balance.
