Theory Philosophy in Cosmology

Several cosmologies and cosmogonies since the dawn of times have been proposed to account for observations of the Universe. Cosmologies, nowadays included, implies philosophical considerations and consequences

Cosmologies, Cosmogonies

As far as how human groups represented to themselves the world surrounding them, most began with religious, mythical explanations all supposing a origin. Which may be a 'world egg' like for the Finns, Chinese and Indians, a single entity like for Tibetan Buddhists, Greeks before the philosophers with the concept of Gaia, the Aztecs or Egyptians, a craft a corpse of a god for Babylonians or Northmen Norse mythology, from chaotic materials to Japanese, or a emanation from fundamental principles like in the Brahmanic religion or the yin and yang of the Tao. Greek philosophers were the first in history to search for rational, funding concepts, basing upon what could be observed and with the idea of a underlying general matter or principle, or numerous of those. That translated into varied views from one philosopher to another. Empedocles four-element theory (Earth, Air, Fire and Water), Leucippus and Democritus atomic views, or Pythagoras numbers are best known. Aristotle, as far as he is concerned, opposed to the concept of vacuum with its sentence 'Nature abhors a vacuum' as it would bring to a infinite speed as he also deviced the notion of an infinitely divisible continuum which could apply to space and time. Here and there several theories may sound questioning as heralding must modern concepts, like Anaximander 'apeiron' roughly corresponding to the modern concept of a quantum foam, Indian philosopher Kanada with light and heat varieties of the same substance or 5th century A.D. Buddhist atomist philosopher Dignaga point-sized, durationless, and energy-made atoms. Abrahamic Judaic, Christian and Islamic religions characterized with the denial of temporal finitism against any infinite past and a infinite temporal regress of events cannot exist, hence a beginning of time matching the concept of Creation. Each civilization, from such basic interrogations and concepts also came with a model of the Universe or Nature. Babylonians viewed the world like a flat disk floating in the ocean, later Greek philosophers as epitomized by Aristotle and in agreement with astronomical observations by Ptolemy proposed the Earth-centered spheres system of a infinite and eternal Universe. The Universe is featuring a infinite space and eternal existence as it contained a single set of concentric spheres of finite size corresponding to the fixed stars, the Sun and planets all in rotation around a spherical, unmoving Earth. According to Aristotle, the ultimate of such spheres caused the motion and change of everything. Most common term used by Greek philosophers to qualify the Universe was To Pan (The All), encompassing all matter and all space as other terms were also kosmos (the world) or fusis (Nature) all words to be found back in current western languages. Some improved models led to heliocentricism with Pythagorean Philolaus, Aristarchus of Samos, or Seleucus of Seleucia which did not take however in Antiquity as they surfaced somehow also by the Indians and Arabs. The idea of a rotating Earth about itself had been more widespread. Western Middle Ages mostly were Aristotelian. The Copernician and Galilean revolutions by the Renaissance have their inspiration still ill-known, with Arab theories of the 15th and 16th centuries heralding their western counterparts by some decades only. That came to the Newtonian physics in the Modern Times as a general cosmology at the time beared several inconsistencies like the infinite energy delivered by finite stars or a infinite space with matter causing infinite gravitational forces and instabilities. Those were first solved mostly by Immanuel Kant in the 18th century that stars are not distributed uniformly throughout space but grouped into galaxies instead. A interaction between new domains of physics in the 19th century like electromagnetism and thermodynamics, a renewal view of old concepts like the Copernician or Galilean relativity or question of frames of reference or the will of Einstein to a comprehensive explanation of Nature, resulted into the 20th century Big Bang theory and quantum physics which provide for the current view of Nature. Our Universe originated from a hot, dense early point -or a quantum fluctuation which can create matter and energy from nothing- and since then has been expanding into the constituents of matter, then stars and galaxies and is supposed to expand indefinitely, with gravity defined like a curvature of spacetime and the general geometry of the Universe close to flat. The ultimate composition of matter at the smallest scales resuls from six leptons and six quarks interacting through forces and force carriers. In termes of debate about whether such views require any divine spark or not, a idea might be that such conditions were due to the existence of laws of physics which, in turn, might need some originator

Philosophical Questions in Astronomy Nowadays

Since the Copernician Revolution, the place of Man into the Universe was strongly relativized. Nowadays, a renewed interest appeared to re-valorize that place. By 1974, Brandon Carter, a British astronomer at the Observatory of Paris-Meudon, France, asserted what is known like the 'anthropic principle,' according to which 'the Universe was tuned in a extremely accurate fashion so Man be able to appear in it.' The Universe since its beginnings with the early Big Bang seems tuned to allow for mankind. Would the handful of 'fundamental constants of Nature' -which determine Nature like the speed of light, the mass of the electron, etc- have been different, no human would exist now to think about the Universe! The presence of early massive stars also allowed for as they produced the heavy elements absolutely necessary to life. Such a debate intermingled into a older one, that between 'necessity and chance,' as enounced by French biologist Jacques Monod in the 1970's. Is mankind what it is nowadays due to chance or to necessity?

• the accuracy of the initial tuning of the Universe being 10⁶⁰, should one hold that the anthropic accuracy of our Univers is due to chance, one has to postulate the existence of at last 10⁶⁰ universes to allow for that ours been born from the possibilities of chance! Such a view unfolded into a series of theories allowing such a large number of universes like the following. The multiverses (which via the 'energy of void' may skip a creative principle with the Universes been born of the sole reality of physical processus. Some theorecists of the multiverses proponed such views to counter the Big Bang Universe and then the anthropic principle which were too close to monotheistic religions' stands. The idea of a cyclical universe through the Big Crunch, which is a theory rather compatible with Buddhism, which, further, is associating conscience and matter). Some think also that universes can be born from black holes, in a Big Bang, as others think that a universe, in a a quantum way, would split in two each time a decision is taken thus yielding a infinity of universes. Or, at last, the string theories with additional dimensions allowing a illimited number of geometries. For a part, such theories are of the order of metaphysics because the existence of the universes they suppose is inacessible forever to any science investigation
• should one hold for necessity which states that the Universe was predestined to be what it is, and that one has no need of the probabilistic theories of the multiple universes, that is however a metaphysical stand altogether, which mostly is a philosophy of the 'primary cause,' which was first stated by Aristotle and Plato, because that brings to a king of creating principle, which the science as much in the impossibility of demonstrating. Such a view, on a other hand, brings the question of what relationship exists between the creating principle (more simply, a god) and time with such questions like from when the time is dating back -from before the Universe or from its inception only

Those questions mostly arose from the wall to which cosmologists have been brought through the Big Bang theory and quantum mechanics. That wall is the one of the Planck time, a barrier beyond which scientists can't go beyond because they need a quantum theory of gravity. A quantum theory of gravity is a one which would reconcile the theory of Relativity -which is the explanation to the large-scale mechanisms of the Universe- and quantum mechanics -which is the one to the world of particles. The search for that mathematical construction also generated the search for a theory of All, which could unify all the forces of Nature. Those debates further are complicated as each political school often favours such or such of the theories encours