The evolution of galaxies https://www.mpg.de/7298320/the-evolution-of-galaxies
When we look up to the sky on a dark, clear summer night (rare in Germany) we see the shimmering band of the Milky Way stretching from horizon to horizon. This is our home in the Universe, a galaxy consisting of approximately one hundred billion stars.
perspective, this means that the embryonic galaxy grew over time from gas streams fed