How Will Our Universe End? Big Crunch Theory

This articleultimate fate of the universe is a topic in physical cosmology, whose theoretical restrictions allow possible scenarios for the evolution and ultimate fate of the universe to be described and evaluated.

Confirmation of the Big Bang mostly depends on knowing the rate of expansion, average density of matter, and the physical properties of the [1]mass–energyin the universe.There is a strong consensus among cosmologists that the shape of the universe is considered "flat" (parallel lines stay parallel) and will continue to expand forever.[2][3]Factors that need to be considered in determining the universe's origin and ultimate fate include the average motions of galaxies, the shape and structure of the universe, and the amount of dark matter and dark energy that the universe contains.Emerging scientific basis[edit]Theory[edit]The theoretical scientific exploration of the ultimate fate of the universe became possible with Albert Einstein's 1915 theory of general relativity.

There are several possible solutions to the equations of general relativity, and each solution implies a possible ultimate fate of the universe.Alexander Friedmann proposed several solutions in 1922, as did Georges Lemaître in 1927.

Some cosmologists are studying whether dark energy which varies in time (due to a portion of it being caused by a scalar field in the early universe) can solve thecrisis in cosmology.Upcoming galaxy surveys from theUpcoming galaxy surveys from the[7]Euclid,Nancy Grace RomanandJames Webbspace telescopes (and data fromnext-generation ground-based telescopes) are expected to further develop our understanding of dark energy (specifically whether it is best understood as a constant energy intrinsic to space, as a time varying quantum field or as something else entirely).[8]Role of the shape of the universe[edit]The current scientific consensus of most cosmologists is that the ultimate fate of the universe depends on its overall shape, how much dark energy it contains and on the equation of state which determines how the dark energy density responds to the expansion of the universe.

The ultimate fate of an open universe with dark energy is either universal heat death or a "Big Rip"[12][13][14] where the acceleration caused by dark energy eventually becomes so strong that it completely overwhelms the effects of the [15]gravitational,electromagneticandstrongbinding forces.

With dark energy, the expansion rate of the universe initially slows down, due to the effects of gravity, but eventually increases, and the ultimate fate of the universe becomes the same as that of an open universe.Theories about the end of the universe[edit]The fate of the universe may be determined by its density.

As the energy density, scale factor and expansion rate become infinite, the universe ends as what is effectively a singularity.In the special case of phantom dark energy, which has supposed negative kinetic energy that would result in a higher rate of acceleration than other cosmological constants predict, a more sudden big rip could occur.Big Crunch[edit]The Big Crunch hypothesis is a symmetric view of the ultimate fate of the universe.

New York: Playboy Press.ISBN0-87223-748-6.OCLC7924027.Islam, Jamal N. (1983).The Ultimate Fate of the Universe.

Cambridge: Cambridg University Press.ISBN0-521-24814-0.OCLC8728162.External links[edit]Baez, J., 2004, "The End of the Universe".Caldwell, R. R.; Kamionski, M.; Weinberg, N. N. (2003). "Phantom Energy and Cosmic Doomsday".Physical Review Letters.91(7): 071301.arXiv:astro-ph/0302506.Bibcode:2003PhRvL..91g1301C.doi:10.1103/physrevlett.91.071301.PMID12935004.S2CID119498512.Hjalmarsdotter, Linnea, 2005, "Cosmological parameters."George Musser(2010)."Could Time End?".Scientific American.303(3): 84–91.Bibcode:2010SciAm.303c..84M.doi:10.1038/scientificamerican0910-84.PMID20812485.Vaas, Ruediger; Steinhardt, Paul J.; Turok, Neil (2007). "Dark Energy and Life's Ultimate Future".arXiv:physics/0703183.A Brief History of the End of Everything, aBBC Radio 4series.Cosmology at Caltech.Jamal Nazrul Islam(1983):The Ultimate Fate of the UniverseCambridge University Press, Cambridge, England.ISBN978-0-521-11312-0. (Digital print version published in 2009).

Confirmation of the Big Bang mostly depends on knowing the rate of expansion, average density of matter, and the physical properties of the [1] There is a strong consensus among cosmologists that the shape of the universe is considered "flat" (parallel lines stay parallel) and will continue to expand forever.[2][3] Factors that need to be considered in determining the universe's origin and ultimate fate include the average motions of galaxies, the shape and structure of the universe, and the amount of dark matter and dark energy that the universe contains.

Theory[edit] The theoretical scientific exploration of the ultimate fate of the universe became possible with Albert Einstein's 1915 theory of general relativity.

There are several possible solutions to the equations of general relativity, and each solution implies a possible ultimate fate of the universe.

Starting in 1998, observations of supernovas in distant galaxies have been interpreted as consistent with a universe whose [6] The current scientific consensus of most cosmologists is that the ultimate fate of the universe depends on its overall shape, how much dark energy it contains and on the equation of state which determines how the dark energy density responds to the expansion of the universe.

Recent observations conclude, from [3]7.5 billion yearsafter the Big Bang, that the expansion rate of the universe has probably been increasing, commensurate with the Open Universe theory.However, measurements made by theHowever, measurements made by the[9]Wilkinson Microwave Anisotropy Probesuggest that the universe is either flat or very close to flat.[2] The current scientific consensus of most cosmologists is that the ultimate fate of the universe depends on its overall shape, how much dark energy it contains and on the equation of state which determines how the dark energy density responds to the expansion of the universe.

The ultimate fate of an open universe with dark energy is either universal heat death or a "Big Rip"[12][13][14] where the acceleration caused by dark energy eventually becomes so strong that it completely overwhelms the effects of the [15] If the average density of the universe exactly equals the critical density so that , then the geometry of the universe is flat: as in Euclidean geometry, the sum of the angles of a triangle is 180 degrees and parallel lines continuously maintain the same distance.

With dark energy, the expansion rate of the universe initially slows down, due to the effects of gravity, but eventually increases, and the ultimate fate of the universe becomes the same as that of an open universe.

The Big Crunch hypothesis is a symmetric view of the ultimate fate of the universe.

Therefore, quantum mechanics has given rise to an alternative version of the Big Bang theory, specifically that the universe [26]tunneledinto existence and had a finite density consistent with quantum mechanics, before evolving in a manner governed by classical physics.Also, if the universe is closed, this theory would predict that once this universe collapses it will spawn another universe in an event similar to the Big Bang after a universal singularity is reached or a repulsive quantum force causes re-expansion.Also, if the universe is closed, this theory would predict that once this universe collapses it will spawn another universe in an event similar to the Big Bang after a universal singularity is reached or a repulsive quantum force causes re-expansion.[26] The Big Crunch hypothesis is a symmetric view of the ultimate fate of the universe.

Islam, Jamal N. (1983).The Ultimate Fate of the Universe.

Jamal Nazrul Islam(1983):The Ultimate Fate of the UniverseCambridge University Press, Cambridge, England.ISBN978-0-521-11312-0. (Digital print version published in 2009).