A century ago, astronomy’s Great Debate foreshadowed today’s view of the universe

The argument between Harlow Shapley and Heber Curtis was ultimately settled by Edwin Hubble

- More than 2 years ago

Harlow Shapley, Heber Curtis

On April 26, 1920, astronomers Harlow Shapley (left) and Heber Curtis (right) presented their views on the scope of the cosmos.

From left: Smithsonian Institution Archives, Accession 90-105, Science Service Records, Image No. SIA2008-5931; Rockefeller University

Counting universes ought to be easy.