  We point out that a primordial magnetic field can be generated in the
electroweak phase transition by a non-Abelian bootstrap, where the field is
generated by currents of W's, which in turn are extracted from the vacuum by
the magnetic field. This magnetic field is produced as a vortex condensate at
the electroweak phase transition. It becomes stringy as a consequence of the
dynamical evolution due to magnetohydrodynamics.
