Great Debate (astronomy)

The Shapley -Curtis debate, also known as The Great Debate (english The Great Debate ) and bundled the discussion at the beginning of the 20th century, which eventually led to a new understanding of the nature of galaxies and the size of the universe.

The debate between the astronomers Harlow Shapley and Heber Curtis took place on April 26, 1920 in Baird Auditorium of the National Museum of Natural History in Washington. They circled around the size of our Milky Way and the question of whether the then known as spiral nebulae galaxies small objects are further away in the Milky Way or a lot and separated from the Milky Way. On this day, the two scientists presented independent technical presentations on the size scale of the universe, which in the evening was followed by a public discussion.

Shapley was of the opinion that the Milky Way is much greater than previously believed by most astronomers, and that the sun is not at its center. Spiral nebulae he saw as gas clouds in this single giant galaxy at '. Curtis took a much smaller model of the Milky Way, but saw spiral nebulae as independent of the Milky Way -like objects at a great distance.

Both participants were drawn from the knowledge at the time partly right and partly wrong conclusions. The Milky Way is actually much bigger than that assumed by Curtis, according to current knowledge. Later evidence, for example the discovery of Cepheids in the Andromeda Galaxy and other galaxies by Edwin Hubble, but showed that the spiral nebulae outside yourself of the great Milky Way proposed by Shapley are still far and independent island universes, '.