Timeline of cosmological theories

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This timeline of cosmological theories and discoveries is a chronological record of the development of humanity's understanding of the cosmos over the last two-plus millennia. Modern cosmological ideas follow the development of the scientific discipline of physical cosmology.


  • c. 16th century BCE – Mesopotamian cosmology has a flat, circular Earth enclosed in a cosmic ocean.[1]
  • c. 15th–11th century BCE – The Rigveda of Hinduism has some cosmological hymns, particularly in the late book 10, notably the Nasadiya Sukta which describes the origin of the universe, originating from the monistic Hiranyagarbha or "Golden Egg".Primal matter remains manifest for 311.04 trillion years and unmanifest for an equal length. The universe remains manifest for 4.32 billion years and unmanifest for an equal length. Innumerable universes exist simultaneously. These cycles have and will last forever, driven by desires.
  • 6th century BCE – The Babylonian world map shows the Earth surrounded by the cosmic ocean, with seven islands arranged around it so as to form a seven-pointed star. Contemporary Biblical cosmology reflects the same view of a flat, circular Earth swimming on water and overarched by the solid vault of the firmament to which are fastened the stars.
  • 6th–4th century BCE – Greek philosophers, as early as Anaximander,[2] introduce the idea of multiple or even infinite universes.[3] Democritus further detailed that these worlds varied in distance, size; the presence, number and size of their suns and moons; and that they are subject to destructive collisions.[4] Also during this time period, the Greeks established that the earth is spherical rather than flat.[5][6]
  • 4th century BCE – Aristotle proposes an Earth-centered universe in which the Earth is stationary and the cosmos (or universe) is finite in extent but infinite in time. However, others like Philolaus and Hicetas rejected geocentrism.[7] Plato seems to have argued that the universe did have a beginning, but Aristotle and others interpreted his words differently.[8]
  • 4th century BCE – De Mundo – Five elements, situated in spheres in five regions, the less being in each case surrounded by the greater – namely, earth surrounded by water, water by air, air by fire, and fire by ether – make up the whole Universe.[9]
  • 3rd century BCE – Aristarchus of Samos proposes a Sun-centered universe
  • 3rd century BCE – Archimedes in his essay The Sand Reckoner, estimates the diameter of the cosmos to be the equivalent in stadia of what we call two light years
  • 2nd century BCE – Seleucus of Seleucia elaborates on Aristarchus' heliocentric universe, using the phenomenon of tides to explain heliocentrism. Seleucus was the first to prove the heliocentric system through reasoning. Seleucus' arguments for a heliocentric cosmology were probably related to the phenomenon of tides.According to Strabo (1.1.9), Seleucus was the first to state that the tides are due to the attraction of the Moon, and that the height of the tides depends on the Moon's position relative to the Sun. Alternatively, he may have proved heliocentricity by determining the constants of a geometric model for it.[10]
  • 2nd century CE-5th century CE-Jain cosmology considers the loka, or universe, as an uncreated entity, existing since infinity, the shape of the universe as similar to a man standing with legs apart and arm resting on his waist. This Universe, according to Jainism, is broad at the top, narrow at the middle and once again becomes broad at the bottom..
  • c. 2nd century BCE–3rd century CE – In Hindu cosmology, the Manusmriti (1.67–80) and Puranas describe time as cyclical, with a new universe (planets and life) created by Brahma every 8.64 billion years. The universe is created, maintained, and destroyed within a kalpa (day of Brahma) period lasting for 4.32 billion years, and is followed by a pralaya (night) period of partial dissolution equal in duration. In some Puranas (e.g. Bhagavata Purana), a larger cycle of time is described where matter (mahat-tattva or universal womb) is created from primal matter (prakriti) and root matter (pradhana) every 622.08 trillion years, from which Brahma is born.[11] The elements of the universe are created, used by Brahma, and fully dissolved within a maha-kalpa (life of Brahma; 100 of his 360-day years) period lasting for 311.04 trillion years containing 36,000 kalpas (days) and pralayas (nights), and is followed by a maha-pralaya period of full dissolution equal in duration.[12][13][14][15] The texts also speak of innumerable worlds or universes.[16]
  • 2nd century CE – Ptolemy proposes an Earth-centered universe, with the Sun, Moon, and visible planets revolving around the Earth
  • 5th century (or earlier) – Ancient Buddhist texts speak of "hundreds of thousands of billions, countlessly, innumerably, boundlessly, incomparably, incalculably, unspeakably, inconceivably, immeasurably, inexplicably many worlds" to the east, and "infinite worlds in the ten directions".[17][18]
  • 5th centuriy – Several astronomers propose a Sun-centered universe, including Aryabhata.
  • 5th century BCE - Jewish talmud gives an argument for finite universe Theory along with explanation.
  • 6th century – John Philoponus proposes a universe that is finite in time and argues against the ancient Greek notion of an infinite universe
  • 7th century – The Qur'an says in Chapter 21: Verse 30 – "Have those who disbelieved not considered that the heavens and the earth were a joined entity, and We separated them ... "
  • 9th–12th centuries – Al-Kindi (Alkindus), Saadia Gaon (Saadia ben Joseph) and Al-Ghazali (Algazel) support a universe that has a finite past and develop two logical arguments for the notion.
  • 964 – Abd al-Rahman al-Sufi (Azophi), a Persian astronomer, makes the first recorded observations of the Andromeda Galaxy from Earth, in his Book of Fixed Stars
  • 12th century – Fakhr al-Din al-Razi discusses Islamic cosmology, rejects Aristotle's idea of an Earth-centered universe, and, in the context of his commentary on the Qur'anic verse, "All praise belongs to God, Lord of the Worlds," proposes that the universe has more than "a thousand thousand worlds beyond this world such that each one of those worlds be bigger and more massive than this world as well as having the like of what this world has."[19]
  • 14th century- Christian scholar Nicholas of Cusa and proposed that the Earth rotates on its axis in his book, On Learned Ignorance (1440).[20]
  • 15th century – Ali Qushji provides empirical evidence for the Earth's rotation on its axis and rejects the stationary Earth theories of Aristotle and Ptolemy
  • 15th–16th centuries – Nilakantha Somayaji and Tycho Brahe propose a universe in which the planets orbit the Sun and the Sun orbits the Earth, known as the Tychonic system
  • 1543 – Nicolaus Copernicus publishes his heliocentric universe in his De revolutionibus orbium coelestium
  • 1576 – Thomas Digges modifies the Copernican system by removing its outer edge and replacing the edge with a star-filled unbounded space
  • 1584 – Giordano Bruno proposes a non-hierarchical cosmology, wherein the Copernican Solar System is not the center of the universe, but rather, a relatively insignificant star system, amongst an infinite multitude of others
  • 1610 – Johannes Kepler uses the dark night sky to argue for a finite universe
  • 1687 – Sir Isaac Newton's laws describe large-scale motion throughout the universe
  • 1720 – Edmund Halley puts forth an early form of Olbers' paradox
  • 1729 – James Bradley discovers the aberration of light, due to the Earth's motion around the Sun.
  • 1744 – Jean-Philippe de Cheseaux puts forth an early form of Olbers' paradox
  • 1755 – Immanuel Kant asserts that the nebulae are really galaxies separate from, independent of, and outside the Milky Way Galaxy; he calls them island universes.
  • 1785 – William Herschel proposes a heliocentric model of the universe that our Sun is at or near the center of the universe, which at the time was assumed to only be the Milky Way Galaxy.[21]
  • 1791 – Erasmus Darwin pens the first description of a cyclical expanding and contracting universe in his poem The Economy of Vegetation
  • 1826 – Heinrich Wilhelm Olbers puts forth Olbers' paradox
  • 1837 – Following over 100 years of unsuccessful attempts, Friedrich Bessel, Thomas Henderson and Otto Struve measure the parallax of a few nearby stars; this is the first measurement of any distances outside the Solar System.
  • 1848 – Edgar Allan Poe offers first correct solution to Olbers' paradox in Eureka: A Prose Poem, an essay that also suggests the expansion and collapse of the universe
  • 1860s – William Huggins develops astronomical spectroscopy; he shows that the Orion nebula is mostly made of gas, while the Andromeda nebula (later called Andromeda Galaxy) is probably dominated by stars.



Since 2000[edit]

See also[edit]

Physical cosmology[edit]

Belief systems[edit]



  1. ^ Horowitz (1998), p. xii
  2. ^ This is a matter of debate:
    • Cornford, F. M. (1934). "Innumerable Worlds in Presocratic Philosophy". The Classical Quarterly. 28 (1): 1–16. doi:10.1017/S0009838800009897. ISSN 1471-6844. S2CID 170168443.
    • Curd, Patricia; Graham, Daniel W. (2008). The Oxford Handbook of Presocratic Philosophy. Oxford University Press. pp. 239–41. ISBN 978-0-19-972244-0.
    • Gregory, Andrew (2016). "7 Anaximander: One Cosmos or Many?". Anaximander: A Re-assessment. Bloomsbury Publishing. pp. 121–142. ISBN 978-1472506252.
  3. ^
  4. ^ "there are innumerable worlds of different sizes. In some there is neither sun nor moon, in others they are larger than in ours and others have more than one. These worlds are at irregular distances, more in one direction and less in another, and some are flourishing, others declining. Here they come into being, there they die, and they are destroyed by collision with one another. Some of the worlds have no animal or vegetable life nor any water."
  5. ^ "Ancient Greek Astronomy and Cosmology | Modeling the Cosmos | Articles and Essays | Finding Our Place in the Cosmos: From Galileo to Sagan and Beyond | Digital Collections | Library of Congress". Library of Congress. Washington, DC.
  6. ^ Blakemore, Erin. "Christopher Columbus Never Set Out to Prove the Earth was Round". History.com.
  7. ^ Encyclopædia Britannica (2019). "heliocentrism | Definition, History, & Facts". Encyclopedia Britannica. Encyclopædia Britannica.
  8. ^ Sorabji, Richard (2005). The Philosophy of the Commentators, 200–600 AD: Physics. Cornell University Press. p. 175. ISBN 978-0-8014-8988-4.
  9. ^ Aristotle; Forster, E. S. (Edward Seymour); Dobson, J. F. (John Frederic) (1914). De Mundo. Oxford: The Clarendon Press. p. 2.{{cite book}}: CS1 maint: multiple names: authors list (link)
  10. ^ "Aristarchus of Samos (310-230 BC) | High Altitude Observatory". www2.hao.ucar.edu. Retrieved 2022-06-30.
  11. ^ "Mahattattva, Mahat-tattva: 5 definitions". Wisdom Library. February 10, 2021. Mahattattva (महत्तत्त्व) or simply Mahat refers to a primordial principle of the nature of both pradhāna and puruṣa, according to the 10th century Saurapurāṇa: one of the various Upapurāṇas depicting Śaivism.—[...] From the disturbed prakṛti and the puruṣa sprang up the seed of mahat, which is of the nature of both pradhāna and puruṣa. The mahattattva is then covered by the pradhāna and being so covered it differentiates itself as the sāttvika, rājasa and tāmasa-mahat. The pradhāna covers the mahat just as a seed is covered by the skin. Being so covered there spring from the three fold mahat the threefold ahaṃkāra called vaikārika, taijasa and bhūtādi or tāmasa.
  12. ^ Gupta, S. V. (2010). "Ch. 1.2.4 Time Measurements". In Hull, Robert; Osgood, Jr., Richard M.; Parisi, Jurgen; Warlimont, Hans (eds.). Units of Measurement: Past, Present and Future. International System of Units. Springer Series in Materials Science: 122. Springer. pp. 7–8. ISBN 9783642007378.
  13. ^ Penprase, Bryan E. (2017). The Power of Stars (2nd ed.). Springer. p. 182. ISBN 9783319525976.
  14. ^ Johnson, W.J. (2009). A Dictionary of Hinduism. Oxford University Press. p. 165. ISBN 978-0-19-861025-0.
  15. ^ Fernandez, Elizabeth. "The Multiverse And Eastern Philosophy". Forbes.
  16. ^
  17. ^ Jackson, Roger; Makransky, John (2013). Buddhist Theology: Critical Reflections by Contemporary Buddhist Scholars. Routledge. p. 118. ISBN 978-1-136-83012-9.
  18. ^ Reat, N. Ross; Perry, Edmund F. (1991). A World Theology: The Central Spiritual Reality of Humankind. Cambridge University Press. p. 112. ISBN 978-0-521-33159-3.
  19. ^ Adi Setia (2004), "Fakhr Al-Din Al-Razi on Physics and the Nature of the Physical World: A Preliminary Survey", Islam & Science, 2, archived from the original on 2012-07-10, retrieved 2010-03-02
  20. ^ Misner, Thorne and Wheeler
  21. ^ a b Berendzen, Richard (1975). "Geocentric to heliocentric to galactocentric to acentric: the continuing assault to the egocentric". Vistas in Astronomy. 17 (1): 65–83. Bibcode:1975VA.....17...65B. doi:10.1016/0083-6656(75)90049-5.
  22. ^ Staff (March 17, 2014). "BICEP2 2014 Results Release". National Science Foundation. Retrieved March 18, 2014.
  23. ^ Clavin, Whitney (March 17, 2014). "NASA Technology Views Birth of the Universe". NASA. Retrieved March 17, 2014.
  24. ^ Overbye, Dennis (March 17, 2014). "Space Ripples Reveal Big Bang's Smoking Gun". The New York Times. Retrieved March 17, 2014.
  25. ^ Overbye, Dennis (March 24, 2014). "Ripples From the Big Bang". New York Times. Retrieved March 24, 2014.
  26. ^ a b Ade, P.A.R.; BICEP2 Collaboration (June 19, 2014). "Detection of B-Mode Polarization at Degree Angular Scales by BICEP2". Physical Review Letters. 112 (24): 241101. arXiv:1403.3985. Bibcode:2014PhRvL.112x1101B. doi:10.1103/PhysRevLett.112.241101. PMID 24996078. S2CID 22780831.
  27. ^ "BICEP2 News | Not Even Wrong".
  28. ^ Overbye, Dennis (June 19, 2014). "Astronomers Hedge on Big Bang Detection Claim". New York Times. Retrieved June 20, 2014.
  29. ^ Amos, Jonathan (June 19, 2014). "Cosmic inflation: Confidence lowered for Big Bang signal". BBC News. Retrieved June 20, 2014.
  30. ^ Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P. (2016-02-11). "Observation of Gravitational Waves from a Binary Black Hole Merger". Physical Review Letters. 116 (6): 061102. arXiv:1602.03837. Bibcode:2016PhRvL.116f1102A. doi:10.1103/PhysRevLett.116.061102. ISSN 0031-9007. PMID 26918975. S2CID 124959784.
  31. ^ Castelvecchi, Davide; Witze, Alexandra (11 February 2016). "Einstein's gravitational waves found at last". Nature News. doi:10.1038/nature.2016.19361. S2CID 182916902. Retrieved 11 February 2016.
  32. ^ Blum, Alexander; Lalli, Roberto; Renn, Jürgen (12 February 2016). "The long road towards evidence". Max Planck Society. Retrieved 15 February 2016.
  33. ^ Abbott, B. P.; et al. (LIGO Scientific Collaboration and Virgo Collaboration) (15 June 2016). "GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence". Physical Review Letters. 116 (24): 241103. arXiv:1606.04855. Bibcode:2016PhRvL.116x1103A. doi:10.1103/PhysRevLett.116.241103. PMID 27367379. S2CID 118651851.
  34. ^ Commissariat, Tushna (15 June 2016). "LIGO detects second black-hole merger". Physics World. Institute of Physics. Retrieved 15 June 2016.
  35. ^ "First-ever Image of a Black Hole Published by the Event Horizon Telescope Collaboration". eventhorizontelescope.org. Retrieved 2020-03-30.
  36. ^ "The first picture of a black hole opens a new era of astrophysics". Science News. 2019-04-10. Retrieved 2020-03-30.
  37. ^ "How Does the Event Horizon Telescope Work?". Sky & Telescope. 2019-04-15. Retrieved 2020-03-30.
  38. ^ University of Geneva (10 March 2020). "Solved: The mystery of the expansion of the universe". Phys.org. Retrieved 10 March 2020.
  39. ^ Lombriser, Lucas (10 April 2020). "Consistency of the local Hubble constant with the cosmic microwave background". Physics Letters B. 803: 135303. arXiv:1906.12347. Bibcode:2020PhLB..80335303L. doi:10.1016/j.physletb.2020.135303. S2CID 195750638.
  40. ^ "Rethinking cosmology: Universe expansion may not be uniform (Update)". phys.org. Retrieved 15 May 2020.
  41. ^ "Nasa study challenges one of our most basic ideas about the universe". The Independent. 8 April 2020. Archived from the original on 2022-05-07. Retrieved 23 May 2020.
  42. ^ "Parts of the universe may be expanding faster than others". New Atlas. 9 April 2020. Retrieved 23 May 2020.
  43. ^ "Doubts about basic assumption for the universe". EurekAlert!. Retrieved 23 May 2020.
  44. ^ Migkas, K.; Schellenberger, G.; Reiprich, T. H.; Pacaud, F.; Ramos-Ceja, M. E.; Lovisari, L. (8 April 2020). "Probing cosmic isotropy with a new X-ray galaxy cluster sample through the LX–T scaling relation". Astronomy & Astrophysics. 636: A15. arXiv:2004.03305. Bibcode:2020A&A...636A..15M. doi:10.1051/0004-6361/201936602. ISSN 0004-6361. S2CID 215238834. Retrieved 15 May 2020.
  45. ^ "The laws of physics may break down at the edge of the universe". Futurism. Retrieved 17 May 2020.
  46. ^ "New findings suggest laws of nature 'downright weird,' not as constant as previously thought". phys.org. Retrieved 17 May 2020.
  47. ^ Field, David (28 April 2020). "New Tests Suggest a Fundamental Constant of Physics Isn't The Same Across The Universe". ScienceAlert.com. Retrieved 29 April 2020.
  48. ^ Wilczynska, Michael R.; Webb, John K.; Bainbridge, Matthew; Barrow, John D.; Bosman, Sarah E. I.; Carswell, Robert F.; Dąbrowski, Mariusz P.; Dumont, Vincent; Lee, Chung-Chi; Leite, Ana Catarina; Leszczyńska, Katarzyna; Liske, Jochen; Marosek, Konrad; Martins, Carlos J. A. P.; Milaković, Dinko; Molaro, Paolo; Pasquini, Luca (1 April 2020). "Four direct measurements of the fine-structure constant 13 billion years ago". Science Advances. 6 (17): eaay9672. arXiv:2003.07627. Bibcode:2020SciA....6.9672W. doi:10.1126/sciadv.aay9672. PMC 7182409. PMID 32426462.


  • Bunch, Bryan, and Alexander Hellemans, The History of Science and Technology: A Browser's Guide to the Great Discoveries, Inventions, and the People Who Made Them from the Dawn of Time to Today. ISBN 0-618-22123-9
  • P. de Bernardis et al., astro-ph/0004404, Nature 404 (2000) 955–959.
  • Horowitz, Wayne (1998). Mesopotamian cosmic geography. Eisenbrauns. ISBN 978-0-931464-99-7.
  • P. Mauskopf et al., astro-ph/9911444, Astrophys. J. 536 (2000) L59–L62.
  • A. Melchiorri et al., astro-ph/9911445, Astrophys. J. 536 (2000) L63–L66.
  • A. Readhead et al., Polarization observations with the Cosmic Background Imager, Science 306 (2004), 836–844.