Dear friends, welcome. Today I will take you on a fascinating journey through the vastness of our Universe, exploring one of its most intriguing mysteries: the Boötes Void, also known as “the Great Nothing.”
Imagine an immense area in space, as vast as 330 million light years, but containing very few galaxies. To give you an idea of how huge it is, consider that a light year is the distance light travels in one year, which is about 9.461 trillion kilometers. If we could travel at the speed of light, it would take us 330 million years to cross this void. It’s like lining up 22 million times the distance between the Earth and the Sun (150 million kilometers), or imagine miniaturizing our Solar System to the size of a one-euro coin, then in proportion the entire Boötes Void would be as large as all of Europe.
This colossal void is one of the largest ever discovered and represents one of the most fascinating phenomena in the cosmos. The Great Nothing, surrounded by the superclusters of Ursa Major, Shapley, Hercules, Corona Borealis, and Boötes, contains only about sixty galaxies, arranged in a cylindrical region that crosses the center of the void. In an area of such dimensions, we would expect to find at least 2,000 galaxies.
Creation
When the Universe formed, the matter within it was densely compacted and relatively uniform. However, quantum fluctuations caused slight variations in the density of matter. The denser areas collapsed under their own gravity, attracting matter from the less dense areas. As the Universe expanded, these dense areas coalesced to form galaxies, which in turn attracted each other, creating a gigantic network of filaments across the Universe. These filaments and voids constitute the largest structures in the known Universe, formed by clusters of galaxies that converge. The voids formed as spaces between these filaments, similar to bubbles in a foam. The smaller bubbles merged, forming larger voids. Together, voids and filaments (as we will see later) dominate the overall structure of the Universe.
Supercomputer Simulation
The following image is the result of the Millennium Run project. This extraordinary project used over 10 billion particles to trace the evolution of matter distribution in a cubic region of the Universe over 2 billion light years on each side. Imagine the immensity of this task!
To accomplish this titanic feat, the main supercomputer at the Max Planck Society’s Supercomputing Center in Garching, Germany, was engaged for over a month..
Credit: Millennium Simulation Project – Max Planck Institute for Astrophysics Supercomputer.
Scientists from the Virgo project have applied sophisticated modeling techniques to the 25 terabytes of stored data, managing to recreate the evolutionary histories of about 20 million galaxies that populate this immense volume of space. Not only that, they have also managed to model the supermassive black holes that occasionally power the quasars at their hearts. Using these advanced techniques, the scientists have been able to simulate the formation and evolution of cosmic structures over immense timescales, allowing them to compare the simulated data with large observational surveys. This comparison helps clarify the physical processes underlying the formation and evolution of real galaxies and black holes.
The Discovery
The Boötes Void was discovered in 1981 by the American astronomer Robert Kirshner of the University of Michigan. During a survey of galaxy redshifts to create a three-dimensional map of the Universe, Kirshner and his team discovered a vast empty region. The size of the void and the fact that it contains a few galaxies, though very few, rule out the possibility that the Boötes Void is a black hole or a dark nebula like Barnard 68. By studying the Boötes Void and other similar structures, scientists can learn more about the dark energy that drove their formation during the expansion of the Universe.
Voids are also ideal places to study neutrinos, which travel freely through them. It is hoped that missions like the Euclid satellite can compare neutrino samples in the voids with theoretical predictions to measure the sum of the masses of all neutrino species.
Dear friends, today’s journey has unveiled the mysterious Boötes Void, one of the most fascinating wonders of our Universe. Exploring these immense empty spaces helps us better understand the intricate structure of the cosmos and the forces that shape it. This theme is perfectly in line with our blog, dedicated to exploring and explaining the void that exists not only between atoms and particles but also in the vastness of space. Keep following us on this journey of discovery, always keeping alive the curiosity and wonder for the marvels that surround us.