The Boötes void is a massive spherically-shaped stretch of space near the Bootes constellation. It is known as the Great Nothing, which is a very apt moniker. Scientists estimate that the Bootes void contains only 60 known galaxies, but it is nearly 330 million light-years across. Thousands of galaxies could exist in such a vast area.
Discovery of the Bootes Void
Robert Kirshner discovered the Boote's void in 1981. It is still the largest known void in the universe. Astronomers and astrophysicists once thought that crowded areas filled with galaxies were very common. Advances in technology and research have discovered something very different.
Michael Vogely, an astrophysicist at Drexel University, states that over 60% of the universe is comprised of voids. Research on voids themselves is still in the early stages. Light at the edge of the Bootes void is more than 100 million years old. The observable light may have been created by galaxies that ceased to exist long ago.
Why Do Scientists Study Nothing?
It seems odd that scientists study entities filled with almost nothing. Scientists observe voids to understand how the universe behaves as a whole. The Bootes void helps researchers learn how dark matter and dark energy function.
Some researchers focus on voids to judge the accuracy of Einstein's theory of relativity. The Bootes void is not really empty. It is filled with dark energy. Einstein's theory explained gravity in the universe, but dark energy was unknown in 1915.
The properties of dark matter and dark energy explain their role in the universe.
- Dark matter attracts dark and physical matter.
- Dark energy repels dark and physical matter.
- Dark matter acts within individual galaxies.
- Dark energy acts on the universe as a whole.
The Cosmic Web
Galaxies that contain thousands of stars appear as filaments stretched throughout the universe. The filaments surround massive voids. Scientists describe the arrangement of filaments and voids as the Cosmic Web.
Some scientists believe that the universe once existed as a morass of basic components such as dark matter, hydrogen, helium and lithium. The components were spread evenly throughout space. The Big Bang spread these components around, and dark matter built up in clumps.
Dark matter exerted an immense gravitational pull and drew all matter into clusters. Cosmologists believe clusters of matter formed galaxies. Voids are the empty spaces of dark energy left behind after matter was pulled into isolated clusters throughout the Cosmic Web.
Has Void Research Changed Astronomy?
Astronomers from the United States, Germany, France and Italy used data obtained from voids to create computer simulations of movement in the universe. The dark energy in voids repels galaxies and contributes to the expansion of the universe.
Objects in the universe are in constant motion. Voids do not simply exist. They grow and change and affect the movement of other objects. The Milky Way galaxy containing Earth actually moves through space at a rate of 600 kilometers per second.
The astronomers and other researchers have not found any interactions between voids and matter that conflict with general relativity. Einstein's theory still holds true. They did find that measurements of visible matter and simulations were four times more precise after taking voids into consideration. (For more space info, please click here.)