I love learning about the development of the knowledge that we take for granted today. Only a few short years ago, we didn't even know what a galaxy was. Who knows what we will discover in the future?

Did anyone else think it was strange that this article didn't even mention the importance of dark matter to the formation of galaxies? Without the enormous quantity of dark matter that gravitationally binds our galaxy together the centrifugal force would cause the galaxy to fly apart.

Super-summary: a bunch of stars.