The contribution of VM Slipher to the discovery of the expanding universe

ABSTRACT 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 Hubble's 'discovery graph' of 1929 should be known as the HubbleSlipher 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 incommensurate paradigm shifts