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 monisticHiranyagarbha 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 Map of the World 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 and Earth's rotation in its own axis. He also provides evidences for his theory from his own observations.[10]
3rd century BCE – Archimedes in his essay The Sand Reckoner, estimates the diameter of the cosmos to be the equivalent in stadia of what would in modern times be called 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.[11]
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.[12] 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.[13][14][15][16] The texts also speak of innumerable worlds or universes.[17]
2nd century CE – Ptolemy proposes an Earth-centered universe, with the Sun, Moon, and visible planets revolving around the Earth. He also calculates the positions, orbits and positional equations of the Heavenly bodies along with instruments to measure these quantities in his book The Almagest. His book also cataloged 1022 stars and other astronomical objects which remained the largest astronomical catalogue until the 17th century AD.[18][19]
5th century (or earlier) – 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".[20][21]
5th century – Several Indian astronomers propose a rudimentary Sun-centered universe, including Aryabhata. He also writes a treatise on motion of planets, sun and moon and stars.Aryabhatta puts forward the theory of rotation of the earth in its own axis and explained day and night was caused by the diurnal rotation of the earth. He also provided empirical evidence for his notion from his astronomical experiments and observation.[22]
5th century – The 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 Quran 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.
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 Quranic verse, "All praise belongs to God, Lord of the Worlds," and proposes that the universe has more than "a thousand worlds beyond this world."[23]
14th century – Christian scholar Nicholas of Cusa and proposed that the Earth rotates on its axis in his book, On Learned Ignorance (1440).[24]
14th century – Several European mathematicians and astronomers develop the theory of Earth's rotation including Nicole Oresme. Nicole Oresme also give logical reasoning. empirical evidence and mathematical proofs for his notion.[25][26]
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
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
1912 – Henrietta Leavitt discovers the period-luminosity law for Cepheid variable stars, which becomes a crucial step in measuring distances to other galaxies.
1923 – Edwin Hubble measures distances to a few nearby spiral nebulae (galaxies), the Andromeda Galaxy (M31), Triangulum Galaxy (M33), and NGC 6822. The distances place them far outside the Milky Way, and implies that fainter galaxies are much more distant, and the universe is composed of many thousands of galaxies.
1927 – Georges Lemaître discusses the creation event of an expanding universe governed by the Einstein field equations. From its solutions to the Einstein equations, he predicts the distance-redshift relation.
1928 – Howard P. Robertson briefly mentions that Vesto Slipher's redshift measurements combined with brightness measurements of the same galaxies indicate a redshift-distance relation
1929 – Edwin Hubble demonstrates the linear redshift-distance relation and thus shows the expansion of the universe
1933 – Fritz Zwicky shows that the Coma cluster of galaxies contains large amounts of dark matter. This result agrees with modern measurements, but is generally ignored until the 1970s.
1950 – Fred Hoyle coins the term "Big Bang", saying that it was not derisive; it was just a striking image meant to highlight the difference between that and the Steady-State model.
1961 – Robert Dicke argues that carbon-based life can only arise when the gravitational force is small, because this is when burning stars exist; first use of the weak anthropic principle
1963 – Maarten Schmidt discovers the first quasar; these soon provide a probe of the universe back to substantial redshifts.
1968 – Brandon Carter speculates that perhaps the fundamental constants of nature must lie within a restricted range to allow the emergence of life; first use of the strong anthropic principle
1977 – Gary Steigman, David Schramm, and James Gunn examine the relation between the primordial helium abundance and number of neutrinos and claim that at most five lepton families can exist.
1980 – Alan Guth and Alexei Starobinsky independently propose the inflationary Big Bang universe as a possible solution to the horizon and flatness problems.
1981 – Viatcheslav Mukhanov and G. Chibisov propose that quantum fluctuations could lead to large scale structure in an inflationary universe.
1982 – The first CfA galaxy redshift survey is completed.
1982 – Several groups including James Peebles, J. Richard Bond and George Blumenthal propose that the universe is dominated by cold dark matter.
1983–1987 – The first large computer simulations of cosmic structure formation are run by Davis, Efstathiou, Frenk and White. The results show that cold dark matter produces a reasonable match to observations, but hot dark matter does not.
1988 – The CfA2 Great Wall is discovered in the CfA2 redshift survey.
1988 – Measurements of galaxy large-scale flows provide evidence for the Great Attractor.
1990 – Preliminary results from NASA's COBE mission confirm the cosmic microwave background radiation has a blackbody spectrum to an astonishing one part in 105 precision, thus eliminating the possibility of an integrated starlight model proposed for the background by steady state enthusiasts.
1992 – Further COBE measurements discover the very small anisotropy of the cosmic microwave background, providing a "baby picture" of the seeds of large-scale structure when the universe was around 1/1100th of its present size and 380,000 years old.
1996 – The first Hubble Deep Field is released, providing a clear view of very distant galaxies when the universe was around one-third of its present age.
1998 – Controversial evidence for the fine-structure constant varying over the lifetime of the universe is first published.
1999 – Measurements of the cosmic microwave background radiation with finer resolution than COBE, (most notably by the BOOMERanG experiment see Mauskopf et al., 1999, Melchiorri et al., 1999, de Bernardis et al. 2000) provide evidence for oscillations (the first acoustic peak) in the anisotropy angular spectrum, as expected in the standard model of cosmological structure formation. The angular position of this peak indicates that the geometry of the universe is close to flat.
Since 2000
2001 – The 2dF Galaxy Redshift Survey (2dF) by an Australian/British team gave strong evidence that the matter density is near 25% of critical density. Together with the CMB results for a flat universe, this provides independent evidence for a cosmological constant or similar dark energy.
2002 – The Cosmic Background Imager (CBI) in Chile obtained images of the cosmic microwave background radiation with the highest angular resolution of 4 arc minutes. It also obtained the anisotropy spectrum at high-resolution not covered before up to l ~ 3000. It found a slight excess in power at high-resolution (l > 2500) not yet completely explained, the so-called "CBI-excess".
2003 – NASA's Wilkinson Microwave Anisotropy Probe (WMAP) obtained full-sky detailed pictures of the cosmic microwave background radiation. The images can be interpreted to indicate that the universe is 13.7 billion years old (within one percent error), and are very consistent with the Lambda-CDM model and the density fluctuations predicted by inflation.
2006–2011 – Improved measurements from WMAP, new supernova surveys ESSENCE and SNLS, and baryon acoustic oscillations from SDSS and WiggleZ, continue to be consistent with the standard Lambda-CDM model.
2020 — Physicist Lucas Lombriser of the University of Geneva presents a possible way of reconciling the two significantly different determinations of the Hubble constant by proposing the notion of a surrounding vast "bubble", 250 million light years in diameter, that is half the density of the rest of the universe.[45][46]
^"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."
^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)
^"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.
^Kirschner, Stefan (2021), Zalta, Edward N. (ed.), "Nicole Oresme", The Stanford Encyclopedia of Philosophy (Fall 2021 ed.), Metaphysics Research Lab, Stanford University, retrieved 2022-11-09
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. ISBN0-618-22123-9
P. de Bernardis et al., astro-ph/0004404, Nature 404 (2000) 955–959.
