  The bremsstrahlung produced when heavy nuclei collide is estimated for
central collisions at the Relativistic Heavy Ion Collider. Bremsstrahlung
photons with energies below 100 to 200 MeV are sufficient to discern the gross
features of the space-time evolution of electric charge, if they can be
separated from other sources of photons experimentally. This is illustrated
explicitly by considering two very different models, one Bjorken-like, the
other Landau-like, both of which are constructed to give the same final charge
rapidity distribution.
