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A map of the Boötes Void. The Boötes Void (/ b oʊ ˈ oʊ t iː z / boh-OH-teez) (colloquially referred to as the Great Nothing) [1] is an approximately spherical region of space found in the vicinity of the constellation Boötes, containing only 60 galaxies instead of the 2,000 that should be expected from an area this large, hence its name.
There exist a number of ways for finding voids with the results of large-scale surveys of the universe. Of the many different algorithms, virtually all fall into one of three general categories. [27] The first class consists of void finders that try to find empty regions of space based on local galaxy density. [28]
Outer space, especially the relatively empty regions of the universe outside the atmospheres of celestial bodies; Vacuum, a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure; Free space, a perfect vacuum as expressed in the classical physics model
A vacuum is defined as a space with as little energy in it as possible. Despite the name, the vacuum still has quantum fields.A true vacuum is stable because it is at a global minimum of energy, and is commonly assumed to coincide with the physical vacuum state we live in.
Ultra-high vacuum chambers, common in chemistry, physics, and engineering, operate below one trillionth (10 −12) of atmospheric pressure (100 nPa), and can reach around 100 particles/cm 3. [4] Outer space is an even higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space. [5]
Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space. Most of the remaining mass-energy in the observable universe is made up of an unknown form, dubbed dark matter and dark energy. Outer space does not begin at a definite altitude above Earth's surface.
The idea that "empty" space can have an intrinsic energy associated with it, and that there is no such thing as a "true vacuum" is seemingly unintuitive. It is often argued that the entire universe is completely bathed in the zero-point radiation, and as such it can add only some constant amount to calculations.
The world has no empty space within it, but forms one united whole. This is a necessary result of the sympathy and tension which binds together things in heaven and earth." [ This quote needs a citation ] Chrysippus discusses the Void in his work On Void and in the first book of his Physical Sciences ; so too Apollophanes in his Physics ...