{{Short description|Theory or model concerning the origin of the universe}} {{hatnote group|{{about||the Björk song|Cosmogony (song)|the Obscura album|Cosmogenesis (album)}}}} {{Use dmy dates|date=September 2019}} [[File:Universe expansion2.png|thumb|The Big Bang theory of modern cosmology postulates the universe evolved from a hot dense state.]] '''Cosmogony''', also spelled as '''cosmogeny''',<ref>{{Cite journal |journal=Nature |volume=340 |issue=6228 |language=en |issn=0028-0836 |date=July 1989 |pages=17–18 |doi=10.1038/340017a0 |url=https://www.nature.com/articles/340017a0 |title=The dichotomy of cosmogeny |first=Jonathan J. |last=Halliwell|bibcode=1989Natur.340...17H |url-access=subscription }}</ref> or '''cosmogenesis''',<ref>{{Cite book |isbn=978-0-19-802221-3 |title=Cosmogenesis: the growth of order in the universe |location=New York |publisher=Oxford University Press |date=1990 |editor-first=David |editor-last=Layzer}}</ref> is any model concerning the origin of the cosmos or the universe.<ref name="DicAstro2">{{Cite encyclopedia |year=2012 |title=A Dictionary of Astronomy |publisher=Oxford University Press |last=Ridpath |first=Ian}}</ref><ref name="CosmoToday2">{{Cite journal |last=Woolfson |first=Michael Mark |author-link=Michael Woolfson |year=1979 |title=Cosmogony Today |journal=Quarterly Journal of the Royal Astronomical Society |volume=20 |issue=2 |pages=97–114 |bibcode=1979QJRAS..20...97W}}</ref>
== Types == While cosmogony generally refers to origin stories, the nature and subject of these stories varies with times and sources. Ancient Greece developed a cosmogony focused on the origin of matter, space, and time with a transition from Chaos to Cosmos. This was a form of "philosophical cosmogony" that is distinct from modern empirical science but which nevertheless dealt with many similar questions.<ref>{{Cite book |last=Gregory |first=Andrew |title=Ancient Greek cosmogony |date=2007 |publisher=Duckworth |isbn=978-0-7156-3477-6 |location=London}}</ref>{{rp|7}} Another type of cosmogony focuses on the formation and evolution of the Solar System.<ref name="CosmoToday2" /> or sometimes the formation of galaxies.<ref name="DicAstro2" /> The standard cosmological model of the early development of the universe is the Big Bang theory,<ref name="Wollack">{{Cite web |last=Wollack |first=Edward J. |date=10 December 2010 |title=Cosmology: The Study of the Universe |url=http://map.gsfc.nasa.gov/universe/ |url-status=dead |archive-url=https://web.archive.org/web/20110514230003/http://map.gsfc.nasa.gov/universe/ |archive-date=14 May 2011 |access-date=27 April 2011 |website=Universe 101: Big Bang Theory |publisher=NASA}}</ref> but it is based on a model known to fail at the very earliest times.<ref name="Peacock-1998">{{Cite book |last=Peacock |first=J. A. |url=https://www.cambridge.org/core/product/identifier/9780511804533/type/book |title=Cosmological Physics |date=1998-12-28 |publisher=Cambridge University Press |isbn=978-0-521-41072-4 |edition=1 |doi=10.1017/cbo9780511804533}}</ref>{{rp|275}} Thus modern cosmogony is not generally a consequence of modern cosmology theories.
== Scientific cosmogenesis == A Big Bang model for the dynamics of the universe is widely agreed among cosmologists. Like most physical models, Big Bang models describe changes of state. Few physical models are designed to determine initial conditions: initial states are given by experimental measurements or by hypothesis. In cosmology, the initial state would be the origin of the universe. It is considered a valid challenge to address but there are significant disagreements over even the form of acceptable answers.<ref name=Smeenk-2017>{{Citation |last1=Smeenk |first1=Christopher |title=Philosophy of Cosmology |date=2017 |encyclopedia=The Stanford Encyclopedia of Philosophy |editor-last=Zalta |editor-first=Edward N. |url=https://plato.stanford.edu/archives/win2017/entries/cosmology/ |access-date=2025-09-16 |edition=Winter 2017 |publisher=Metaphysics Research Lab, Stanford University |last2=Ellis |first2=George}}</ref>
=== Initial singularity === {{main|Initial singularity}} Since the Big Bang model describes an expanding and cooling universe, it must have been denser and hotter in the past. Conceptually the model can be extrapolated back to time zero. However, this process cannot be run all the way back to time zero: the standard model assumes a density low enough to avoid quantum effects. As the model is followed to smaller times the density exceeds the validity of general relativity.<ref name=Smeenk-2017/>
=== General relativity initial state === One approach to the limitations of running Big Bang model back to time zero simply stops extrapolating when the limit of valid general relativity is reached. This model by itself fails in several ways. First, the observable universe is much more homogeneous than an extrapolated Big Bang can account for. This problem is called the horizon problem because events on opposite sides of the horizon could not have mixed in the early universe and thus should not be homogeneous now. Second, the expansion of the universe reduces curvature or equivalently increases flatness. Since the universe now is observed to be close to flat, a universe extrapolated back in time would have to be extremely flat. This almost but not quite zero curvature seems unnatural, an issue called the flatness problem. Third, this extrapolation gives poor results when compared to measurements of large scale structure and of the cosmic microwave background (CMB).<ref name=Smeenk-2017/>
=== Initial state theories ===
Several different theories have been proposed as alternative to simple extrapolation of general relativity. The most successful approach is called inflation. In this model the universe goes through a very short phase of intense expansion not predicted by general relativity. The expansion is so immense and fast that all pre-existing particles are diluted and replaced by particles emerging from the field that drove inflation in a process called reheating. An initially homogeneous universe, inflated by an enormous factor explains why we can see homogeneous features across distances which ordinary causality asserts are independent.<ref name=Smeenk-2017/> When combined with the Big Bang and other concepts of cosmology, inflation becomes the consensus or standard model of cosmology, a model which successfully predicts details of large scale structure and the CMB.{{citation needed|date=September 2025}} While inflation has been successful in developing an initial state for Big Bang models, it does not by itself describe the origin of the universe. The rapid expansion erases evidence of physical processes occurring before inflation.<ref name=Smeenk-2017/>
=== Quantum cosmology=== Sean M. Carroll, who specializes in theoretical cosmology and field theory, explains two competing explanations for the origins of the singularity, which is the center of a space in which a characteristic is limitless<ref name=":0">{{Cite web |last=Carroll |first=Sean |date=28 April 2012 |title=A Universe from Nothing? |url=http://blogs.discovermagazine.com/cosmicvariance/2012/04/28/a-universe-from-nothing/#.XMQHyM9KhmA |access-date=22 April 2019 |website=Science for the Curious |archive-date=10 May 2016 |archive-url=https://web.archive.org/web/20160510012738/http://blogs.discovermagazine.com/cosmicvariance/2012/04/28/a-universe-from-nothing/#.XMQHyM9KhmA |url-status=dead }}</ref> (one example is the singularity of a black hole, where gravity is the characteristic that becomes {{nowrap|limitless{{hsp}}{{mdash}}{{hsp}}}}infinite).
When the universe started to expand, the Big Bang occurred, which evidently began the universe.{{citation_needed|date=May 2025}} The other explanation, the Hartle–Hawking state, held by proponents such as Stephen Hawking, asserts that time did not exist when it emerged along with the universe. This assertion implies that the universe does not have a beginning, as time did not exist "prior" to the universe. Hence, it is unclear whether properties such as space or time emerged with the singularity and the known universe.<ref name=":0" /><ref name=":1">{{Cite book |last1=Carroll |first1=Sean |title=Spacetime and Geometry: An Introduction to General Relativity |last2=Carroll |first2=Sean M. |publisher=Pearson |year=2003}}</ref>{{clarify|date=March 2021 |reason=This paragraph is a hopeless muddle after the second sentence.}}
== Mythology == {{Main|Creation myth}} [[File:Sumerian creation myth.jpg|thumb|The Sumerian tablet containing parts of the Eridu Genesis]] [[File:The Untangling of Chaos, or the Creation of the Four Elements LACMA 54.70.1a.jpg|thumb|The Creation of the Four Elements as published by Holland in 1589 from Ovid's book: ''Metamorphoses'']] In mythology, creation or cosmogonic myths are narratives describing the beginning of the universe or cosmos.
Some methods of the creation of the universe in mythology include:
* the will or action of a supreme being or beings, * the process of metamorphosis, * the copulation of female and male deities, * from chaos, * or via a cosmic egg.<ref>{{Cite web |last=Long |first=Charles |title=Creation Myth |url=https://www.britannica.com/topic/creation-myth#ref1239147 |access-date=20 April 2019 |website=Encyclopedia Britannica}}</ref>
Creation myths may be etiological, attempting to provide explanations for the origin of the universe. For instance, Eridu Genesis, the oldest known creation myth, contains an account of the creation of the world in which the universe was created out of a primeval sea (Abzu).<ref>{{Cite web |date=20 July 1998 |title=Eridu Genesis Mesopotamia Epic |url=https://www.britannica.com/topic/Eridu-Genesis |access-date=30 April 2019 |website=Encyclopaedia Britannica |publisher=Encyclopaedia Britannica, Inc}}</ref><ref>{{Cite journal |last=Morris |first=Charles |date=1897 |title=The Primeval Ocean |journal=Proceedings of the Academy of Natural Sciences of Philadelphia |volume=49 |pages=12–17 |jstor=4062253}}</ref> Creation myths vary, but they may share similar deities or symbols. For instance, the ruler of the gods in Greek mythology, Zeus, is similar to the ruler of the gods in Roman mythology, Jupiter.<ref name=":3">{{Cite book |last1=Thury |first1=Eva |title=Introduction to Mythology Contemporary Approaches to Classical and World Myths, 4th ed. |last2=Devinney |first2=Margaret |publisher=Oxford University Press |year=2017 |location=Madison Avenue, New York |pages=4, 187}}</ref> Another example is the ruler of the gods in Tagalog mythology, Bathala, who is similar to various rulers of certain pantheons within Philippine mythology such as the Bisaya's Kaptan.<ref>Garverza, J. K. (2014). The Myths of the Philippines. University of the Philippines.</ref><ref>Jocano, F. L. (1969). Philippine Mythology. Quezon City: Capitol Publishing House Inc.</ref>
thumb| The representation of the Universe as rooted in Serer religion and Cosmogony
Recurring patterns of creation narratives can be identified across various cultures and beliefs. Creation myths are found in most religions, and can be split into five different classifications, based on a system created by Mircea Eliade and his colleague Charles Long:<ref>{{Cite book |last=Long|first=Charles H.|title=Alpha: The myths of creation|date=1963|publisher=Scholars Pr|isbn=978-0-89130-604-7|edition=Reprint|series=Classics in religious studies, Scholars Press and the American Academy of Religion|location=Chico, Calif}}</ref> * Creation ''ex nihilo'' in which the creation is through the thought, word, dream or bodily secretions of a divine being from initial state of nothing. * Earth diver creation in which a diver, usually a bird or amphibian sent by a creator, plunges to the seabed through a primordial ocean to bring up sand or mud which develops into a terrestrial world. * Emergence myths in which progenitors pass through a series of worlds and metamorphoses until reaching the present world. * Creation by the dismemberment of a primordial being, as in the Ymir motif, otherwise known as the world parent myth.<ref>{{cite book | chapter=Ymir Motif | title=Thematic Guide to World Mythology | first=Lorena Laura | last=Stookey | publisher=Bloomsbury Publishing USA | year=2004 | isbn=978-0-313-03937-9 | pages=213–214 | chapter-url=https://books.google.com/books?id=inzDEAAAQBAJ&pg=PA214 }}</ref> * Creation by the splitting or ordering of a primordial unity such as the cracking of a cosmic egg or a bringing order from chaos.<ref name="lm3233">{{cite book |last1=Leonard |first1=Scott A |last2=McClure |first2=Michael|title=Myth and Knowing |year=2004 |publisher=McGraw-Hill |isbn=978-0-7674-1957-4 }}</ref>
== Compared with cosmology == In the humanities, the distinction between cosmogony and cosmology is blurred. For example, in theology, the cosmological argument for the existence of God (pre-cosmic cosmogonic bearer of personhood) is an appeal to ideas concerning the origin of the universe and is thus cosmogonical.<ref name=":2">{{Cite journal |last1=Smeenk |first1=Christopher |last2=Ellis |first2=George |date=Winter 2017 |title=Philosophy of Cosmology |url=https://plato.stanford.edu/archives/win2017/entries/cosmology/ |access-date=30 April 2019 |website=Stanford Encyclopedia of Philosophy}}</ref> Some religious cosmogonies have an impersonal first cause (for example Taoism).<ref>{{Cite web |title=BBC - Religions - Taoism: Gods and spirits |url=https://www.bbc.co.uk/religion/religions/taoism/beliefs/gods.shtml |website=www.bbc.co.uk |publisher=BBC}}</ref>
However, in astronomy, cosmogony can be distinguished from cosmology, which studies the universe and its existence, but does not necessarily inquire into its origins. There is therefore a scientific distinction between cosmological and cosmogonical ideas. Physical cosmology is the science that attempts to explain all observations relevant to the development and characteristics of the universe on its largest scale. Some questions regarding the behaviour of the universe have been described by some physicists and cosmologists as being extra-scientific or metaphysical. Attempted solutions to such questions may include the extrapolation of scientific theories to untested regimes (such as the Planck epoch), or the inclusion of philosophical or religious ideas.<ref name=":1" /><ref name=":2" /><ref name="Wollack" />
== See also == *{{annotated link|Anthropic principle}} *{{annotated link|Chronology of the universe}} *{{annotated link|Cosmography}} *{{annotated link|Ultimate fate of the universe}} *Why is there anything at all?
==References== {{Reflist}}
==External links== *{{Commons category-inline}}
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Category:Cosmogony Category:Creation myths Category:Natural philosophy Category:Origins Category:Physical cosmology Category:Concepts in astronomy