Harlow Shapley

Harlow Shapley's claim to fame is being wrong on one of the most important issues in early 20th-century astronomy. On April 26, 1920, in the halls of the United States Naval Academy of Sciences, Shapley argued against Heber Curtis in the so-called “Great Debate,” where he hypothesized against the presence of galaxies other than the Milky Way. This argument was consistent with a common view of the time, that galaxies are balls of gas shaped like spirals, or “spiral nebulae.” It was also wrong, as Edwin Hubble wrote in a paper published in 1925.

Though Shapley proved to be wrong on a few major scientific issues—he also exaggerated the size of the Milky Way Galaxy, largely because he did not have more modern understandings of how light is absorbed across the galaxy—his work within the scientific community was quite impressive. A president of the American Association of Variable Star Observers (AAVSO) and the American Astronomical Society (AAS) at different points in his career, and the Director of the Harvard College Observatory, he held many leadership roles within astronomy. Most significantly, as Director of the Harvard College Observatory, Shapley was the first to create a graduate astronomy program at Harvard.

Shapley visited the Observatory in August 1921. Whether or not there were multiple galaxies in the universe was still unknown, so Shapley got another chance to battle against Heber Curtis—this time at Middletown, Connecticut for the meeting of the AAS, which Curtis also attended.