The universe, with its vast expanse of stars, planets, and cosmic matter, is a complex and ever-evolving structure. At the heart of this cosmic web lie galaxies, massive systems of stars, gas, dust, and dark matter that are bound together by gravity. Galaxies are not random collections of matter; they are highly organized systems that exhibit specific structures and behaviors. Understanding the formation and evolution of galaxies is central to our comprehension of the universe.

The earliest galaxies began forming shortly after the Big Bang, as matter began to coalesce under the influence of gravity. These early galaxies were small and irregular, lacking the well-defined shapes we see in present-day galaxies. Over time, galaxies merged and grew larger, eventually settling into the diverse forms we recognize today, such as spiral, elliptical, and irregular galaxies. The structures of these galaxies are shaped by a variety of factors, with gravity being the dominant force that governs their organization.

Light plays a crucial role in understanding galactic structures. The radiation emitted by stars, gas clouds, and other objects within a galaxy allows astronomers to study its composition, temperature, and movement. Observing the light emitted from these objects gives us insight into the processes occurring within a galaxy, including star formation, the dynamics of the galaxy's core, and the behavior of supermassive black holes. However, light alone does not reveal the full picture. There is another component of the universe that has a more subtle but profound effect on galactic structures—dark space.