Vesto Slipher and the First Galaxy Redshifts
  Priority in the discovery of the velocity-distance relationship may be
shifting from Edwin Hubble to Georges Lemaitre, but any reassessment of credit
must also consider the contributions of Vesto Slipher. Not only were his spiral
galaxy redshifts a necessary component in all of the original velocity-distance
plots, but it was the quest to explain these unprecedentedly large Doppler
velocities that pointed the way to a new physical interpretation.
