  Thirty-five years after the discovery of rotation-powered pulsars, we still
do not understand the fundamentals of their pulsed emission at any wavelength.
Even detailed pulse profiles cannot identify the location of the emission in a
magnetosphere that extends from the neutron star surface to near the light
cylinder. Compounding the problem are effects of strong gravity at low
altitudes and plasma moving at relativistic speeds in the outer magnetosphere.
I will discuss the role of special and general relativistic effects on pulsar
emission, from inertial frame-dragging near the stellar surface to aberration,
time-of-flight and retardation of the magnetic field near the light cylinder.
Understanding how these effects determine what we observe at different
wavelengths is critical to unraveling the emission physics.
