History of Cosmological Models

Ancient Western Models
* Idea: Until Galileo's observations much later, the universe consisted in the Sun, Moon, 5 planets, and the fixed stars; The western world accepted the idea of changes in the cosmos only after Tycho.
* Earliest sites: Nabta (Egyptian desert, 5000–3000 BC); Stonehenge (England, 3000–2000 BC).
* Mesopotamians: For astrological reasons.

Aristarchos of Samos
* History: First to propose a heliocentric model; his original work on this was lost, but is mentioned by Archimedes; Rejected by Aristotelians, the idea lay dormant until Copernicus, and his values for the sizes and distances of the Sun (too small by a factor 20) and Moon (close) were accepted only in the XVII cy.

Aristotelian
* Idea: Geometric celestial spheres bounded by a sphere of fixed stars (bounded universe inherited from mythology).

Stoic (ca 300 BC, Zeno of Citium)
* Idea: Finite cosmos of stars in an infinite void.
* History: Revived in the late middle ages, influenced by the scientific revolution.

Early Models
* Eudoxus of Cnidus: Spheres for the motion of the planets.
* Epicurus of Samos: (See ca 70 BC Lucretius, De rerum natura) Uniform material universe of unlimited extent, with worlds scattered in an infinite void; all matter composed of atoms, regulated by natural laws.
* Ptolemy: (II cy AD) The most complete geocentric model.

Middle Ages
@ References: Gangui CH(05)-a0806 [Dante and the cosmos of the XIII century].

Renaissance and Other Intermediate Western Models

XVI Century
* Tycho Brahe: Mixed model, with the Sun and Moon revolving around Earth, and the other planets around the Sun; But was a good observer.
* Copernicus: First modern heliocentric model.
* Menocchio: Italian miller, thought that the world is self-created, from chaos, like cheese from milk.

XVII Century
* Idea: It was still thought that interplanetary space was filled with normal air (although the experiments proposed by Pascal on the thinning of the air with altitude had already given positive results).
* Descartes: Nonatomic material system of indefinite extent (Aristotelian and Epicurean).
* Fontenelle: Plurality of worlds.
* Galileo: First use of telescope in astronomy; Support of heliocentric ideas.
* Kepler: Elliptical orbits around the Sun; Three laws of planetary motion.

Newton (Epicurean and Stoic)
* Idea: Atomic material system of finite size in an infinite void.
* History: Newton later on became Epicurean, due to the realized instability of a finite system (didn't consider rotation, proposed later by Wright); The instability of a static uniform distribution is solved by Providence.

Newtonian Cosmology
@ References: Milne QJM(34), QJM(34); McCrea & Milne QJM(34).

XVIII Century
* Herschel: The Milky Way is made of stars; First 3D image of the Milky Way.
* Kant: Island universes.

XIX Century
* History: Fraunhofer, identification of spectral lines in sunlight; 1895, Boltzmann hinted at the possibility of expanding systems of stars.
* Entropic creation argument: An argument for the idea that the universe must have had a beginning, based on the second law of thermodynamics applied to the universe a a whole; Introduced in the late 1860s, although earlier versions of it can be found; Much discussed during the subsequent decades and used in support of divine creation; Debate declined around 1920 but traces of it can still be found in the modern literature on cosmology and religion [@ Kragh HSPBS(07)].

Non-Western Cosmologies
@ Various cultures: Rech(96)nov, 62 [Amazonian]; Kak in(00)phy/98, phy/01 [Puranic], phy/02 [cyclic universe], phy/03 [Babylonian and Indian], in(05)phy/03 [Greek and Indian]; Narayan a0705 [Indian].

References > s.a. cosmological history; cosmological models; history of relativistic physics [XX century models].
@ General: Kuhn 57; Munitz 57; Koestler 59; Crowe 90; Brush SA(92)aug; Crowe 94; Ferguson 99 [obs]; Park 05; Kragh 07.

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Send feedback and suggestions to bombelli at olemiss.edu – Modified 26 jun 2008