ABSTRACT
In all of our discussions of waves thus far, we have glossed over the production of waves [emission] and their subsequent detection [reception]. Furthermore, in the dual representations of waves provided by snapshots at instants in time and observers attentive to particular points in space, there was an unrealistic element of omniscience.1 Here we investigate situations in which emitters or receivers are in motion with respect to the medium through which the wave propagates.
