  We compare the nature of electromagnetic fields and of gravitational fields
in linearized general relativity. We carry out this comparison both
mathematically and visually. In particular the "lines of force" visualizations
of electromagnetism are contrasted with the recently introduced tendex/vortex
eigenline technique for visualizing gravitational fields. Specific solutions,
visualizations, and comparisons are given for an oscillating point quadrupole
source. Among the similarities illustrated are the quasistatic nature of the
near fields, the transverse 1/r nature of the far fields, and the interesting
intermediate field structures connecting these two limiting forms. Among the
differences illustrated are the meaning of field line motion, and of the flow
of energy.
