Great Debate

The 107th anniversary falls on April 26, 2027, in 184 days.

The Great Debate, also called the Shapley–Curtis Debate, was held on 26 April 1920 at the U.S. National Museum in Washington, D.C. between the astronomers Harlow Shapley and Heber Curtis. It concerned the nature of so-called spiral nebulae and the size of the universe.

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