Famous astronomers: How these scientists shaped astronomy

It’s surprising to many to learn that Hubble never offered his support for the claim of expansion, though it was his (and Humason’s) great data that defined it. Slipher had been the first to discover the huge redshifts, which opened the door for Lemaître to propose the expansion model.

Hubble’s reluctance demonstrates the separation between astronomers and theoreticians, though one can be both. He even commented that he preferred to let theorists explain his redshifts, perhaps because redshifts were shown to occur within GR per deSitter’s non-expansion model.