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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Cosmos | 2/5 | https://en.wikipedia.org/wiki/Cosmos | reference | science, encyclopedia | 2026-05-05T13:32:07.201455+00:00 | kb-cron |
=== Anaximander === Anaximander was a pre-Socratic Greek philosopher who is widely referred to as the "father of astronomy" and even as the "father of cosmology" as a result of his works to explain the origin and makeup of the physical universe. He is regarded as the most important of the Ionian philosophers, and was a pupil of Thales. Traditionally, details of his life and opinions are perpetuated not only by Aristotle and Theophrastos, but also by a great number of secondary authors. He lived throughout the fifth and fourth centuries, BCE, and was most likely the first philosopher to try to rationalize the system of the Earth, Sun, and Moon by the use of geometry and mathematics. Anaximander was also said to have created the first map of the world, however, like much of the rest of his works, this has been lost since his time. There is, however, documentation of Anaximander being responsible for the conception of the first mechanical model of the world, which is outlined by a geocentric model. He postulated that the Earth was at the center of the universe, and that its shape was convex and cylindrical, with life existing on one of the two flat sides. Beyond the Earth, sits the other planets, which Anaximander also details the order of. Next are the fixed stars, which he regarded as wheel-like condensations of air filled with fire, provided at certain places with openings through which flames are discharged. Anaximander places the Moon beyond these stars, and assumed it to also be wheel-like in shape, being nineteen times the size of Earth. Finally, on the top of the universe is the Sun, which interacts with the Moon, and the relationship between them is described in terms of aperture, in which a stoppage in would lead to eclipses. In this model, the Sun is a ring, 28 times the size of the Earth, with a hollow rim, filled with fire, which at a certain place is seen through an aperture as in a pair of bellows. He also postulated regarding the formation of thunder and lightning, maintaining that they are caused by the wind becoming compressed inside a thick cloud and suddenly breaking through, causing the loud sound to be heard as the cloud is bursting. He claimed the fissure then looked like a spark because of the contrast with the dark cloud. Anaximander's model set a precedent for succeeding theories, including Copernicus's system, with the major change being the shift away from the geocentric model and towards the heliocentric model of the universe. The explained model, although accredited to Anaximander, did necessarily take from ideas originated in foreign cultures, such as the astronomical wheels which are known from Persian cosmology. But even without detailed commentary, these elements of the Anaximander tradition give a strong impression of an original and courageous thinker making conscious efforts towards producing a rational explanation of fundamental physical principles, the nature and motion of heavenly bodies, the shape of Earth, its place in the universe, etc.
== Early views of cosmos ==
Eastern and Western thought differed greatly in their understanding of space and the organization of the cosmos. The Chinese saw the Cosmos as empty, infinite, and intertwined with the Earth. Western ideas, based on the ancient Greeks' understanding of the cosmos, believed in a multi-planar divided cosmos that was finite and filled with air.
=== European view === Early Europeans viewed the cosmos as a divinely created, spatially finite, bifurcated cosmos, divided into sublunary and superlunary realms. Objects above the lunar disc were believed to be stable, with heavenly bodies believed to be made out of a refined substance called "quintessence". This was understood to be a crystalline, completely transparent substance that held all of the superlunary spheres in perfect order. After their creation by God, these spheres did not change except for their rotation above the Earth. Objects below the lunar sphere were subject to constant combination, separation, and recombination. This was because they consisted of the chaotic elements of earth, air, fire, and water. The idea of celestial spheres was developed in the cosmological models of Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. They believed in a stable cosmos created by God, where distinct realms were subject to different kinds of order. Some Europeans maintained the Aristotelian view that infinity could only be seen as an attribute of God, with the cosmos being finite. Furthermore, following the Aristotelian view that "nature abhors a vacuum", some Europeans believed that the space between the spheres were filled with air. This theory persisted until the Scientific Revolution, when the discovery that the Sun was in the center of the planetary system rocked cosmological understanding to its core. Other theories such as Atomism posited a void of atoms as the fundamental elements of physics, while Stoicism postulated a void allowing for the cosmos to expand and contract in volume through its cycles.