According to astronomers, the Milky Way is a bit of a loner.
A new study presented at the american astronomical society and two subsequent papers published in the Astrophysical Journal detail evidence that our region of the universe has fewer planets, stars, galaxies, and matter than other regions.
The void that our galaxy lives is known as KBC and it’s the largest void we’ve ever found. KBC (named after discoverers Keenan, Barger, and Cowie), is seven times larger than the average galactic void, measuring 1 billion light-years.
The idea that we live in this void is a handy explanation for problems with the Hubble Constant. The Hubble Constant is the unit of measurement used to describe the expansion of the universe. It’s called the ‘constant’ because the rate of expansion should be the same at every point in the universe, but it isn’t – which suggests that there are varying gravitational forces all over the universe.
“No matter what technique you use, you should get the same value for the expansion rate of the universe today. Fortunately, living in a void helps resolve this tension.”
Understanding our place in these voids is integral to learning about the large scale structure of our universe. Our universe is described as “Swiss cheese-like in the sense that it is composed of “normal matter” in the form of voids and filaments. The filaments are made up of superclusters and clusters of galaxies, which in turn are composed of stars, gas, dust and planets. Dark matter and dark energy, which cannot yet be directly observed, are believed to comprise approximately 95 percent of the contents of the universe.”
The latest findings show quite evidently that our galaxy lives in a much larger than average sized void which importantly highlights the differential rates at which our universe is expanding. It’s an important find that will aid astronomers in deciphering the structure of our cosmos.