Cosmic voids are vast, relatively empty regions in the universe, stretching for tens to hundreds of millions of light-years. They are the antithesis of galaxy clusters and filaments, which are densely packed with galaxies.
What are cosmic voids?
- Underdense regions: Cosmic voids are regions in the universe with significantly fewer galaxies than average.
- Large-scale structure: They are part of the large-scale structure of the universe, which is often compared to a cosmic web. The "filaments" of this web are dense regions of galaxies, while the voids are the empty spaces between them.
- Formation: Voids are believed to have formed early in the universe's history due to slight density variations in the early universe. These variations grew over time due to gravity, leading to the formation of denser regions and, consequently, voids.
Properties of cosmic voids:
- Size: Voids can range from tens to hundreds of millions of light-years in diameter.
- Galaxy distribution: They typically contain very few galaxies, often only a handful or even none at all.
- Shape: Voids can have various shapes, including spherical, elongated, or irregular.
Importance of cosmic voids:
- Understanding galaxy formation: Studying cosmic voids can help us understand how galaxies form and evolve. The lack of matter in voids provides a unique environment for studying galaxy formation in the absence of strong gravitational influences.
- Cosmology: Voids can also be used to test cosmological models and constrain the properties of dark energy.
In essence, cosmic voids are the vast, empty spaces that make up a significant portion of the observable universe. They play a crucial role in shaping the large-scale structure of the cosmos and provide valuable insights into the processes of galaxy formation and the evolution of the universe.
