largest cosmic void

The Largest Cosmic Void Ever Observed in Which We Are Living is one of the billions in the vast universe. While this may make us seem insignificant, a closer look at our cosmic neighborhood reveals a different story. Evidence suggests that we reside at the center of the largest cosmic void ever observed, known as the KBC void. This 2-billion light-year-wide region challenges our understanding of the cosmos and defies the fundamental laws of cosmology. This discovery not only changes our perception of the Milky Way’s significance but also opens new avenues for astronomical research and exploration.

Evidence of a Giant Cosmic Void

Growing evidence suggests that we live in the center of a gigantic cosmic void—the largest ever observed. Astronomers first proposed this void in 2013, and since then, supporting evidence has continued to accumulate. This void, however, challenges our fundamental understanding of the cosmos.

The Enigma of Our Cosmic Void

Defying Cosmological Principles

According to the cosmological principle, matter in the universe should be evenly distributed on a large scale. This principle allows scientists to apply the same physical laws to both nearby objects and those at the edges of the early universe. However, the existence of this void suggests that matter is not uniformly distributed, but rather clumps into regions of varying densities.

Observations and Theories

Indranil Banik, a postdoctoral research fellow at the University of St. Andrews, supports the idea that we reside in a significant underdensity. Banik co-authored a paper published in the Monthly Notices of the Royal Astronomical Society that suggests we may be near the center of this void, known as the KBC void, which spans about 2 billion light-years and could fit 20,000 Milky Way  galaxies in a row.

The Implications of the KBC Void

Local Cosmic Behavior

The KBC void isn’t completely empty; it’s about 20% emptier than the surrounding space. This deficit causes unusual behavior in our local cosmic neighborhood, where nearby stars and galaxies move away from us faster than expected. This anomaly is related to the Hubble constant, a value that describes the universe’s rate of expansion. The galaxies and stars in our region seem to be moving faster than the Hubble constant predicts, defying our cosmological laws.

The Hubble Tension

This discrepancy in the Hubble constant, known as the Hubble tension, has puzzled astronomers. Banik and his colleagues propose that the void might explain this tension. High-density regions outside the void could be pulling galaxies and stars toward them, causing faster movement within the void. This could explain why cosmologists observe a higher Hubble constant locally.

Unresolved Questions

Extent and Influence of the Void

largest cosmic void

Brian Keating, a cosmologist and physics professor at UC San Diego, acknowledges the void hypothesis but highlights remaining questions. For instance, how far does the void’s influence extend? If the void is not representative of the wider cosmos, it may only offer a local solution to the Hubble tension, not a global one.

Limitations of Current Models

Keating also notes that the results depend on the type of void model used. Different models predict varying effects on the bulk flow, or the average speed of galaxies. This means that while the cosmic void Milky Way  could be a solution, it is not definitive proof.

Alternative Theories;

Early Dark Energy

Another potential solution is the early dark energy theory, which suggests a new form of energy influenced the universe’s expansion rate in its early stages. However, this theory conflicts with certain established truths about the universe, such as the ages of ancient stars.

Future Research

Banik plans to analyze supernovae data to determine whether the Hubble constant aligns with the standard cosmological model outside the void. If his theory is correct, there should be no Hubble tension beyond the void’s borders.


Until further research provides more answers, the Hubble tension remains an unresolved mystery. Whether our cosmic void holds the key to this puzzle or not, it continues to challenge and expand our understanding of the universe.