The contribution of VM Slipher to the discovery of the expanding
  universe
  A brief history of the discovery of the expanding universe is presented, with
an emphasis on the seminal contribution of VM Slipher. It is suggested that the
well-known Hubble graph of 1929 could also be known as the Hubble-Slipher
graph. It is also argued that the discovery of the expanding universe matches
the traditional view of scientific advance as a gradual process of discovery
and acceptance, and does not concur with the Kuhnian view of science
progressing via abrupt paradigm shifts.
