Henrietta Swan Leavitt they became an important part of the evidence that "spiral nebulae" are independent galaxies located far outside of our own Milky Way. Thus, Leavitt's discovery would forever change our picture of the universe, as it prompted Harlow Shapley to move our Sun from the center of the galaxy in the "Great Debate" and Edwin Hubble to move our galaxy from the center of the universe. Leavitt's discovery of a way to accurately measure distances on an inter-galactic scale, paved the way for modern astronomy's understanding of the structure and scale of the universe. The accomplishments of Edwin Hubble, the American
Archive of Our Own Trello board. Stories on Archive of Our Own can be sorted into categories and tagged based on elements of the stories, including characters and ships involved and other more specific tags. Volunteers called "tag wranglers" manually connect synonymous tags to bolster the site's search system, allowing it to understand "mermaids", "mermen", and "merfolk" as constituents of the "merpeople" tag, for example. Archive of Our Own allows users to rate their stories by intended age ("General audience", "Teen and up audiences", "Mature", and "Explicit"), relationships, orientations and pairings ("F/F", "M/M", "F/M", "Multi", "Other", and "Gen"), and to supply content warnings for