Physics and astrophysics have played central roles in shaping our understanding of the universe through scientific observation and experiment. Physical cosmology was shaped through both mathematics and observation in an analysis of the whole universe. The universe is generally understood to have begun with the Big Bang, followed almost instantaneously by cosmic inflation, an expansion of space from which the universe is thought to have emerged 13.799 ± 0.021billion years ago.[8]Cosmogony studies the origin of the universe, and cosmography maps the features of the universe.
In Diderot's Encyclopédie, cosmology is broken down into uranology (the science of the heavens), aerology (the science of the air), geology (the science of the continents), and hydrology (the science of waters).[9]
Metaphysical cosmology has also been described as the placing of humans in the universe in relationship to all other entities. This is exemplified by Marcus Aurelius's observation that a man's place in that relationship: "He who does not know what the world is does not know where he is, and he who does not know for what purpose the world exists, does not know who he is, nor what the world is."[10]
Discoveries
Physical cosmology
Physical cosmology is the branch of physics and astrophysics that deals with the study of the physical origins and evolution of the universe. It also includes the study of the nature of the universe on a large scale. In its earliest form, it was what is now known as "celestial mechanics," the study of the heavens. Greek philosophers Aristarchus of Samos, Aristotle, and Ptolemy proposed different cosmological theories. The geocentricPtolemaic system was the prevailing theory until the 16th century when Nicolaus Copernicus, and subsequently Johannes Kepler and Galileo Galilei, proposed a heliocentric system. This is one of the most famous examples of epistemological rupture in physical cosmology.
Isaac Newton's Principia Mathematica, published in 1687, was the first description of the law of universal gravitation. It provided a physical mechanism for Kepler's laws and also allowed the anomalies in previous systems, caused by gravitational interaction between the planets, to be resolved. A fundamental difference between Newton's cosmology and those preceding it was the Copernican principle—that the bodies on Earth obey the same physical laws as all celestial bodies. This was a crucial philosophical advance in physical cosmology.
Modern scientific cosmology is widely considered to have begun in 1917 with Albert Einstein's publication of his final modification of general relativity in the paper "Cosmological Considerations of the General Theory of Relativity"[11] (although this paper was not widely available outside of Germany until the end of World War I). General relativity prompted cosmogonists such as Willem de Sitter, Karl Schwarzschild, and Arthur Eddington to explore its astronomical ramifications, which enhanced the ability of astronomers to study very distant objects. Physicists began changing the assumption that the universe was static and unchanging. In 1922, Alexander Friedmann introduced the idea of an expanding universe that contained moving matter.
In parallel to this dynamic approach to cosmology, one long-standing debate about the structure of the cosmos was coming to a climax – the Great Debate (1917 to 1922) – with early cosmologists such as Heber Curtis and Ernst Öpik determining that some nebulae seen in telescopes were separate galaxies far distant from our own.[12] While Heber Curtis argued for the idea that spiral nebulae were star systems in their own right as island universes, Mount Wilson astronomer Harlow Shapley championed the model of a cosmos made up of the Milky Waystar system only. This difference of ideas came to a climax with the organization of the Great Debate on 26 April 1920 at the meeting of the U.S. National Academy of Sciences in Washington, D.C. The debate was resolved when Edwin Hubble detected Cepheid Variables in the Andromeda Galaxy in 1923 and 1924.[13][14] Their distance established spiral nebulae well beyond the edge of the Milky Way.
Since around 1990, several dramatic advances in observational cosmology have transformed cosmology from a largely speculative science into a predictive science with precise agreement between theory and observation. These advances include observations of the microwave background from the COBE,[18] WMAP[19] and Planck satellites,[20] large new galaxy redshift surveys including 2dfGRS[21] and SDSS,[22] and observations of distant supernovae and gravitational lensing. These observations matched the predictions of the cosmic inflation theory, a modified Big Bang theory, and the specific version known as the Lambda-CDM model. This has led many to refer to modern times as the "golden age of cosmology".[23]
In 2014, the BICEP2 collaboration claimed that they had detected the imprint of gravitational waves in the cosmic microwave background. However, this result was later found to be spurious: the supposed evidence of gravitational waves was in fact due to interstellar dust.[24][25]
Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation and eschatology. Creation myths are found in most religions, and are typically split into five different classifications, based on a system created by Mircea Eliade and his colleague Charles Long.
Types of Creation Myths based on similar motifs:
Creation ex nihilo in which the creation is through the thought, word, dream or bodily secretions of a divine being.
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.
Creation by the splitting or ordering of a primordial unity such as the cracking of a cosmic egg or a bringing order from chaos.[27]
Philosophy
Cosmology deals with the world as the totality of space, time and all phenomena. Historically, it has had quite a broad scope, and in many cases was found in religion.[28] Some questions about the Universe are beyond the scope of scientific inquiry but may still be interrogated through appeals to other philosophical approaches like dialectics. Some questions that are included in extra-scientific endeavors may include:[29][30]
What is the ultimate reason (if any) for the existence of the universe? Does the cosmos have a purpose? (see teleology)
Does the existence of consciousness have a role in the existence of reality? How do we know what we know about the totality of the cosmos? Does cosmological reasoning reveal metaphysical truths? (see epistemology)
Historical cosmologies
Table notes: the term "static" simply means not expanding and not contracting. Symbol G represents Newton's gravitational constant; Λ (Lambda) is the cosmological constant.
^Hille, Karl, ed. (13 October 2016). "Hubble Reveals Observable Universe Contains 10 Times More Galaxies Than Previously Thought". NASA. Retrieved 17 October 2016.
^Hetherington, Norriss S. (2014). Encyclopedia of Cosmology (Routledge Revivals): Historical, Philosophical, and Scientific Foundations of Modern Cosmology. Routledge. p. 116. ISBN 978-1-317-67766-6.
^Luminet, Jean-Pierre (2008). The Wraparound Universe. CRC Press. p. 170. ISBN 978-1-4398-6496-8. Extract of page 170.
^"Introduction: Cosmology – space" Archived 3 July 2015 at the Wayback Machine. New Scientist. 4 September 2006.
^"Cosmology", Oxford Dictionaries.
^Overbye, Dennis (25 February 2019). "Have Dark Forces Been Messing With the Cosmos? – Axions? Phantom energy? Astrophysicists scramble to patch a hole in the universe, rewriting cosmic history in the process". The New York Times. Retrieved 26 February 2019.
^Spergel, David N. (Fall 2014). "Cosmology Today". Daedalus. 143 (4): 125–133. doi:10.1162/DAED_a_00312. S2CID 57568214.
^Planck Collaboration (1 October 2016). "Planck 2015 results. XIII. Cosmological parameters". Astronomy & Astrophysics. 594 (13). Table 4 on page 31 of PDF. arXiv:1502.01589. Bibcode:2016A&A...594A..13P. doi:10.1051/0004-6361/201525830. S2CID 119262962.
^Diderot (Biography), Denis (1 April 2015). "Detailed Explanation of the System of Human Knowledge". Encyclopedia of Diderot & d'Alembert – Collaborative Translation Project. Retrieved 1 April 2015.
^The thoughts of Marcus Aurelius Antoninus viii. 52.
^Einstein, Albert (1952). "Cosmological considerations on the general theory of relativity". The Principle of Relativity. Dover. pp. 175–188. Bibcode:1952prel.book..175E.{{cite book}}: CS1 maint: date and year (link)
^Dodelson, Scott (30 March 2003). Modern Cosmology. Elsevier. ISBN 978-0-08-051197-9.
^Falk, Dan (18 March 2009). "Review: The Day We Found the Universe by Marcia Bartusiak". New Scientist. 201 (2700): 45. doi:10.1016/S0262-4079(09)60809-5. ISSN 0262-4079.
^Hubble, E. P. (1 December 1926). "Extragalactic nebulae". The Astrophysical Journal. 64: 321. Bibcode:1926ApJ....64..321H. doi:10.1086/143018. ISSN 0004-637X.
^Martin, G. (1883). "G. DELSAULX. — Sur une propriété de la diffraction des ondes planes; Annales de la Société scientifique de Bruxelles; 1882". Journal de Physique Théorique et Appliquée (in French). 2 (1): 175. doi:10.1051/jphystap:018830020017501. ISSN 0368-3893.
^Hubble, Edwin (15 March 1929). "A Relation Between Distance and Radial Velocity Among Extra-Galactic Nebulae". Proceedings of the National Academy of Sciences of the United States of America. 15 (3): 168–173. Bibcode:1929PNAS...15..168H. doi:10.1073/pnas.15.3.168. ISSN 0027-8424. PMC 522427. PMID 16577160.
^Penzias, A. A.; Wilson, R. W. (1 July 1965). "A Measurement of Excess Antenna Temperature at 4080 Mc/s". The Astrophysical Journal. 142: 419–421. Bibcode:1965ApJ...142..419P. doi:10.1086/148307. ISSN 0004-637X.
^Boggess, N. W.; Mather, J. C.; Weiss, R.; Bennett, C. L.; Cheng, E. S.; Dwek, E.; Gulkis, S.; Hauser, M. G.; Janssen, M. A.; Kelsall, T.; Meyer, S. S. (1 October 1992). "The COBE mission – Its design and performance two years after launch". The Astrophysical Journal. 397: 420–429. Bibcode:1992ApJ...397..420B. doi:10.1086/171797. ISSN 0004-637X.
^Parker, Barry R. (1993). The vindication of the big bang : breakthroughs and barriers. New York: Plenum Press. ISBN 0-306-44469-0. OCLC 27069165.
^"Computer Graphics Achievement Award". ACM SIGGRAPH 2018 Awards. SIGGRAPH '18. Vancouver, British Columbia, Canada: Association for Computing Machinery. 12 August 2018. p. 1. doi:10.1145/3225151.3232529. ISBN 978-1-4503-5830-9. S2CID 51979217.
^Science, American Association for the Advancement of (15 June 2007). "NETWATCH: Botany's Wayback Machine". Science. 316 (5831): 1547. doi:10.1126/science.316.5831.1547d. ISSN 0036-8075. S2CID 220096361.
^Paraficz, D.; Hjorth, J.; Elíasdóttir, Á (1 May 2009). "Results of optical monitoring of 5 SDSS double QSOs with the Nordic Optical Telescope". Astronomy & Astrophysics. 499 (2): 395–408. arXiv:0903.1027. Bibcode:2009A&A...499..395P. doi:10.1051/0004-6361/200811387. ISSN 0004-6361.
^Sample, Ian (4 June 2014). "Gravitational waves turn to dust after claims of flawed analysis". the Guardian.
^Cowen, Ron (30 January 2015). "Gravitational waves discovery now officially dead". Nature. doi:10.1038/nature.2015.16830. S2CID 124938210.
^Dennis Overbye (1 December 2014). "New Images Refine View of Infant Universe". The New York Times. Retrieved 2 December 2014.
^Leonard & McClure 2004, pp. 32–33.
^Crouch, C. L. (8 February 2010). "Genesis 1:26-7 As a statement of humanity's divine parentage". The Journal of Theological Studies. 61 (1): 1–15. doi:10.1093/jts/flp185.
^"Publications – Cosmos". www.cosmos.esa.int. Retrieved 19 August 2018.
^Aristotle, On the Heavens, ii, 13.
^Most of Anaximander's model of the Universe comes from pseudo-Plutarch (II, 20–28):
"[The Sun] is a circle twenty-eight times as big as the Earth, with the outline similar to that of a fire-filled chariot wheel, on which appears a mouth in certain places and through which it exposes its fire, as through the hole on a flute. [...] the Sun is equal to the Earth, but the circle on which it breathes and on which it's borne is twenty-seven times as big as the whole earth. [...] [The eclipse] is when the mouth from which comes the fire heat is closed. [...] [The Moon] is a circle nineteen times as big as the whole earth, all filled with fire, like that of the Sun".
^Aristotle (1914). Forster, E. S.; Dobson, J. F. (eds.). De Mundo. Oxford University Press. 393a.
^"The components from which he made the soul and the way in which he made it were as follows: In between the Being that is indivisible and always changeless, and the one that is divisible and comes to be in the corporeal realm, he mixed a third, intermediate form of being, derived from the other two. Similarly, he made a mixture of the Same, and then one of the Different, in between their indivisible and their corporeal, divisible counterparts. And he took the three mixtures and mixed them together to make a uniform mixture, forcing the Different, which was hard to mix, into conformity with the Same. Now when he had mixed these two with Being, and from the three had made a single mixture, he redivided the whole mixture into as many parts as his task required, each part remaining a mixture of the Same, the Different and Being." (35a–b), translation Donald J. Zeyl.
^Plato, Timaeus, 36c.
^Plato, Timaeus, 36d.
^Plato, Timaeus, 39d.
^Yavetz, Ido (February 1998). "On the Homocentric Spheres of Eudoxus". Archive for History of Exact Sciences. 52 (3): 222–225. Bibcode:1998AHES...52..222Y. doi:10.1007/s004070050017. JSTOR 41134047. S2CID 121186044.
^Crowe, Michael (2001). Theories of the World from Antiquity to the Copernican Revolution. Mineola, New York: Dover. p. 23. ISBN 0-486-41444-2.
^Easterling, H. (1961). "Homocentric Spheres in De Caelo". Phronesis. 6 (2): 138–141. doi:10.1163/156852861x00161. JSTOR 4181694.
^Lloyd, G. E. R. (1968). The critic of Plato. Aristotle: The Growth and Structure of His Thought. Cambridge University Press. ISBN 978-0-521-09456-6.
^Hirshfeld, Alan W. (2004). "The Triangles of Aristarchus". The Mathematics Teacher. 97 (4): 228–231. doi:10.5951/MT.97.4.0228. ISSN 0025-5769. JSTOR 20871578.
^Bruce S. Eastwood, Ordering the Heavens: Roman Astronomy and Cosmology in the Carolingian Renaissance (Leiden: Brill, 2007), pp. 238–239.
^Mirabello, Mark (15 September 2016). A Traveler's Guide to the Afterlife: Traditions and Beliefs on Death, Dying, and What Lies Beyond. Simon and Schuster. p. 23. ISBN 978-1-62055-598-9.
^Gilbert, William (1893). "Book 6, Chapter III". De Magnete. Translated by Mottelay, P. Fleury. (Facsimile). New York: Dover Publications. ISBN 0-486-26761-X.
Sources
Bragg, Melvyn (2023). "The Universe's Shape". bbc.co.uk. BBC. Retrieved 23 May 2023. Melvyn Bragg discusses shape, size and topology of the universe and examines theories about its expansion. If it is already infinite, how can it be getting any bigger? And is there really only one?
"Cosmic Journey: A History of Scientific Cosmology". history.aip.org. American Institute of Physics. 2023. Retrieved 23 May 2023. The history of cosmology is a grand story of discovery, from ancient Greek astronomy to -space telescopes.
Dodelson, Scott; Schmidt, Fabian (2020). Modern Cosmology 2nd Edition. Academic Press. ISBN 978-0128159484. Download full text: Dodelson, Scott; Schmidt, Fabian (2020). "Scott Dodelson - Fabian Schmidt - Modern Cosmology (2021) PDF" (PDF). scribd.com. Academic Press. Retrieved 23 May 2023.
"Genesis, Search for Origins. End of mission wrap up". genesismission.jpl.nasa.gov. NASA, Jet Propulsion Laboratory, California Institute of Technology. Retrieved 23 May 2023. About 4.6 billion years ago, the solar nebula transformed into the present solar system. In order to chemically model the processes which drove that transformation, we would, ideally, like to have a sample of that original nebula to use as a baseline from which we can track changes.
Leonard, Scott A; McClure, Michael (2004). Myth and Knowing. McGraw-Hill. ISBN 978-0-7674-1957-4.
Lyth, David (12 December 1993). "Introduction to Cosmology". arXiv:astro-ph/9312022. These notes form an introduction to cosmology with special emphasis on large scale structure, the cmb anisotropy and inflation. Lectures given at the Summer School in High Energy Physics and Cosmology, ICTP (Trieste) 1993.) 60 pages, plus 5 Figures.
"NASA/IPAC Extragalactic Database (NED)". ned.ipac.caltech.edu. NASA. 2023. Retrieved 23 May 2023. April 2023 Release Highlights Database Updates
"NASA/IPAC Extragalactic Database (NED)". ned.ipac.caltech.edu. NASA. 2020. Retrieved 23 May 2023. NED-D: A Master List of Redshift-Independent Extragalactic Distances
Sophia Centre. The Sophia Centre for the Study of Cosmology in Culture, University of Wales Trinity Saint David.
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