Cosmological principle Astronomer William Keel explains: The cosmological principle is usually stated formally as 'Viewed on a sufficiently large scale, the properties of the Universe are the same for all observers.' This amounts to the strongly philosophical statement that the part of the Universe which we can see is a fair sample, and that the same physical laws apply throughout. In essence, this in a sense says that the Universe is knowable and is playing fair with scientists.[1] The cosmological principle contains three implicit qualifications and two testable consequences. The first implicit qualification is that "observers" means any observer at any location in the universe, not simply any human observer at any location on Earth: as Andrew Liddle puts it, "the cosmological principle [means that] the universe looks the same whoever and wherever you are The cosmological principle is first clearly asserted in the Philosophiæ Naturalis Principia Mathematica (1687) of Isaac Newton. Implications[edit]
Eternal return Eternal return (also known as "eternal recurrence") is a concept that the universe has been recurring, and will continue to recur, in a self-similar form an infinite number of times across infinite time or space. The concept is found in Indian philosophy and in ancient Egypt and was subsequently taken up by the Pythagoreans and Stoics. With the decline of antiquity and the spread of Christianity, the concept fell into disuse in the Western world, with the exception of Friedrich Nietzsche, who connected the thought to many of his other concepts, including amor fati. In addition, the philosophical concept of eternal recurrence was addressed by Arthur Schopenhauer. It is a purely physical concept, involving no supernatural reincarnation, but the return of beings in the same bodies. Premise[edit] The basic premise proceeds from the assumption that the probability of a world coming into existence exactly like our own is greater than zero (we know this because our world exists). Judaism[edit]
Cyclic model A cyclic model (or oscillating model) is any of several cosmological models in which the universe follows infinite, or indefinite, self-sustaining cycles. For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a big bang and ending with a big crunch; in the interim, the universe would expand for a period of time before the gravitational attraction of matter causes it to collapse back in and undergo a bounce. Overview[edit] In the 1920s, theoretical physicists, most notably Albert Einstein, considered the possibility of a cyclic model for the universe as an (everlasting) alternative to the model of an expanding universe. However, work by Richard C. One new cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. Other cyclic models include Conformal cyclic cosmology and Loop quantum cosmology. See also[edit]
Shape of the Universe The shape of the universe is the local and global geometry of the universe, in terms of both curvature and topology (though, strictly speaking, it goes beyond both). When physicsist describe the universe as being flat or nearly flat, they're talking geometry: how space and time are warped according to general relativity. When they talk about whether it open or closed, they're referring to its topology.[1] Although the shape of the universe is still a matter of debate in physical cosmology, based on the recent Wilkinson Microwave Anisotropy Probe (WMAP) measurements "We now know that the universe is flat with only a 0.4% margin of error", according to NASA scientists. [2] Theorists have been trying to construct a formal mathematical model of the shape of the universe. Two aspects of shape[edit] The local geometry of the universe is determined by whether the density parameter Ω is greater than, less than, or equal to 1. Local geometry (spatial curvature)[edit] Global geometry[edit]
Dyson's eternal intelligence The intelligent beings would begin by storing a finite amount of energy. They then use half (or any fraction) of this energy to power their thought. When the energy gradient created by unleashing this fraction of the stored fuel was exhausted, the beings would enter a state of zero-energy-consumption until the universe cooled. Two recent observations have presented problems for Dyson's scenario. However, even if intelligence cannot continue its own survival indefinitely in an ever-expanding Universe, it may be able to create a `baby universe' via a wormhole in spacetime, add some DNA[original research?] See also[edit] References[edit] Ultimate fate of the universe The ultimate fate of the universe is a topic in physical cosmology. Many possible fates are predicted by rival scientific theories, including futures of both finite and infinite duration. Once the notion that the universe started with a rapid inflation nicknamed the Big Bang became accepted by the majority of scientists,[1] the ultimate fate of the universe became a valid cosmological question, one depending upon the physical properties of the mass/energy in the universe, its average density, and the rate of expansion. There is a growing consensus among cosmologists that the universe is flat and will continue to expand forever.[2][3] The ultimate fate of the universe is dependent on the shape of the universe and what role dark energy will play as the universe ages. Emerging scientific basis[edit] Theory[edit] The theoretical scientific exploration of the ultimate fate of the universe became possible with Albert Einstein's 1916 theory of general relativity. Observation[edit] Big Rip[edit]
Ekpyrotic universe The ekpyrotic universe, or ekpyrotic scenario, is a cosmological model of the origin and shape of the universe. The name comes from a Stoic term ekpyrosis (Ancient Greek ἐκπύρωσις ekpurōsis) meaning conflagration or in Stoic usage "conversion into fire".[1] The ekpyrotic model of the universe is an alternative to the standard cosmic inflation model for the very early universe; both models accommodate the standard Big Bang Lambda-CDM model of our universe.[2][3] The ekpyrotic model is a precursor to, and part of, some cyclic models. The ekpyrotic model came out of work by Neil Turok and Paul Steinhardt and maintains that the universe did not start in a singularity, but came about from the collision of two branes. This collision avoids the primordial singularity and superluminal expansion of spacetime while preserving nearly scale-free density fluctuations and other features of the observed universe. See also[edit] Notes and references[edit] Further reading[edit] P.
Hindu cycle of the universe See also Hindu units of measurement. This is similar to the Cyclical Universe Theory in physical cosmology. The Big Bang is described as the birth of the universe (Brahma), the life of the universe then follows (Vishnu), and the Big Crunch would be described as the destruction of the universe (Shiva). In a number of stories from the Puranas the continual creation and destruction of the universe is equated to the outwards and inwards breaths of the gigantic cosmic Maha Vishnu. Hindu thesis of creation[edit] Initially everything was unmanifested and was one without a second . In vishnu purana ,It is stated that the purusha(GOD) manifests himself into three forms to maintain the material realm or the manifested realm . Karnodakasayi Vishnu expands himself as Garbhodakasayivisnu and enters into each universe and from Garbhodakasayivisnu originates bhrama from the naval . Hindu viewpoint of modern cosmology[edit] Even string theory finds a place in the Hindu texts. The end of the universe[edit]
Hindu cosmology In Hindu cosmology the universe is cyclically created and destroyed. The Hindu literature, such as Vedas, Puranas, cites the creation of universe. They describe the aspects of evolution, astronomy, etc. Description[edit] The Hindu cosmology and timeline is the closest to modern scientific timelines[1] and even more which might indicate that the Big Bang is not the beginning of everything,[2] but just the start of the present cycle preceded by an infinite number of universes and to be followed by another infinite number of universes.[3] The Rig Veda questions the origin of the cosmos in: "Neither being (sat) nor non-being was as yet. Large scale structure of the Universe according to one Hindu cosmology. Map 2: Intermediate neighbourhood of the Earth according to one Hindu cosmology. Map 3: Local neighbourhood of the Earth according to one Hindu cosmology. Overview of Yugas: Further elaborations from the Vedic texts[edit] Rig Veda[edit] The Puranas[edit] Multiverse in Hinduism[edit] See also[edit]
Buddhist cosmology Buddhist cosmology is the description of the shape and evolution of the Universe according to the Buddhist scriptures and commentaries. Introduction[edit] The self-consistent Buddhist cosmology which is presented in commentaries and works of Abhidharma in both Theravāda (31 planes, Sakwala Vibhanga) and Mahāyāna traditions, is the end-product of an analysis and reconciliation of cosmological comments found in the Buddhist sūtra and vinaya traditions. No single sūtra sets out the entire structure of the universe. Kalpa Vibhangaya However, in several sūtras the Buddha describes other worlds and states of being, and other sūtras describe the origin and destruction of the universe. Buddhist cosmology can be divided into two related kinds: spatial cosmology, which describes the arrangement of the various worlds within the universe, and temporal cosmology, which describes how those worlds come into existence, and how they pass away. Spatial cosmology[edit] Vertical cosmology[edit]