How Are Galaxies Created?
Supernovas play key roles in the development of galaxies. The debris that they scatter throughout space is the building material for other stars, planets, etc, adding to the overall makeup of a galaxy. Galaxies begin with huge masses of dark gases that begin to shrink due to the effects of gravitational forces caused by dense materials. Some galaxies begin to spin forcing the outer areas to flatten out forming a spiral. Galaxies that do not spin will normally take the shape of a sphere or ellipse. The first stars are formed near the center. The gases or clouds of dust attract other clouds of dust forming more stars near the edges.