n.

(天文)宇宙、(学問の)領域、分野

関: area、cosmic、domain、field、realm、region、regional、space、territory

WordNet

everything that exists anywhere; "they study the evolution of the universe"; "the biggest tree in existence" (同)existence, creation, world, cosmos, macrocosm
everything stated or assumed in a given discussion (同)universe of discourse
select (a team or individual player) for a game; "The Buckeyes fielded a young new quarterback for the Rose Bowl"
the space around a radiating body within which its electromagnetic oscillations can exert force on another similar body not in contact with it (同)field of force, force_field
a particular kind of commercial enterprise; "they are outstanding in their field" (同)field_of_operation, line of business
a region in which active military operations are in progress; "the army was in the field awaiting action"; "he served in the Vietnam theater for three years" (同)field of operations, theater, theater of operations, theatre, theatre of operations
the area that is visible (as through an optical instrument) (同)field of view
(computer science) a set of one or more adjacent characters comprising a unit of information
(mathematics) a set of elements such that addition and multiplication are commutative and associative and multiplication is distributive over addition and there are two elements 0 and 1; "the set of all rational numbers is a field"
a geographic region (land or sea) under which something valuable is found; "the diamond fields of South Africa"
a piece of land cleared of trees and usually enclosed; "he planted a field of wheat"
all of the horses in a particular horse race
all the competitors in a particular contest or sporting event
somewhere (away from a studio or office or library or laboratory) where practical work is done or data is collected; "anthropologists do much of their work in the field"
answer adequately or successfully; "The lawyer fielded all questions from the press"
catch or pick up (balls) in baseball or cricket
play as a fielder
place at intervals; "Space the interviews so that you have some time between the different candidates"
an empty area (usually bounded in some way between things); "the architect left space in front of the building"; "they stopped at an open space in the jungle"; "the space between his teeth"
the unlimited expanse in which everything is located; "they tested his ability to locate objects in space"; "the boundless regions of the infinite" (同)infinite
a blank character used to separate successive words in writing or printing; "he said the space is the most important character in the alphabet" (同)blank
a blank area; "write your name in the space provided" (同)blank space, place
an area reserved for some particular purpose; "the laboratorys floor space"
one of the areas between or below or above the lines of a musical staff; "the spaces are the notes F-A-C-E"
the extent of a 2-dimensional surface enclosed within a boundary; "the area of a rectangle"; "it was about 500 square feet in area" (同)expanse, surface_area
a part of a structure having some specific characteristic or function; "the spacious cooking area provided plenty of room for servants"
a particular geographical region of indefinite boundary (usually serving some special purpose or distinguished by its people or culture or geography); "it was a mountainous area"; "Bible country" (同)country
a part of an animal that has a special function or is supplied by a given artery or nerve; "in the abdominal region" (同)region
a subject of study; "it was his area of specialization"; "areas of interest include..."
the approximate amount of something (usually used prepositionally as in `in the region of' (同)neighborhood
the extended spatial location of something; "the farming regions of France"; "religions in all parts of the world"; "regions of outer space" (同)part
a knowledge domain that you are interested in or are communicating about; "it was a limited realm of discourse"; "here we enter the region of opinion"; "the realm of the occult" (同)realm
a large indefinite location on the surface of the Earth; "penguins inhabit the polar regions"
the geographical area under the jurisdiction of a sovereign state; "American troops were stationed on Japanese soil" (同)soil
an area of knowledge or interest; "his questions covered a lot of territory"
(cosmology) a universe that is spatially closed and in which there is sufficient matter to halt the expansion that began with the big bang; the visible matter is only 10 percent of the matter required for closure but there may be large amounts of dark mat
the view that the universe resembles a clock built by God and ticking along according to Newtonian mechanics

PrepTutorEJDIC

《the universe,時に the Universe》『宇宙』(cosmos);森羅万象;[全]人類(humankind) / {C}世界,領域,分野
〈C〉『野原』,[牧]草地;田;畑;《the fields》田野,田畑 / 〈C〉(雪・氷などの)原,広がり / 〈C〉(鉱物などの)産出地,埋蔵地 / 〈C〉『戦場』(battlefield);戦闘(battle) / 〈C〉(スポーツの)『競技場』;(陸上のトラックに対して)フィールド / 〈C〉(ある用途の)場,地面 / 〈C〉(研究・活動などの)『分野』,領域 / 《the~》現地 / 〈C〉(電気・磁気などの)場;(レンズの)視界 / 〈C〉(絵・旗などの)地,下地 / 《the~》《集合的に》(キツネ狩り・競技の)参加者;(競馬の)出走馬;(野球の)守備選手 / (野球・クリケットで)〈打球〉‘を'さばく / 〈選手〉‘を'出場させる,守備につける / (野球・クリケットで)野手をつとめる
〈U〉『空間』,広がり / 〈U〉『宇宙』,地球の大気圏外(outer space) / 〈C〉〈U〉『間隔』,距離;《しばしば複数形で》空地 / 〈C〉(特定目的のための)『場所』 / 〈U〉《しばしばa~》時間 / 〈C〉〈U〉スペース,余白,余地 / 〈C〉線間(譜表において五線の間の部分) / …‘を'間隔をおいて配置する《+『out』+『名,』+『名』+『out』》
〈U〉〈C〉『面積』 / 〈C〉『地域』,『地方』(region, district) / 〈C〉(活動・研究・興味などの及ぶ)『範囲』,『領域』(range)《+『of』+『名』》 / 〈C〉《英》=areaway 1
(地理的な)『地域』,『地帯』;(特に広大な)地方 / 《複数形で》(宇宙などの)区分,界,属 / (身体の)部分 / (学問などの)分野,領域 / 《複数形で》(都会から離れた)地方
〈C〉〈U〉(広い)『地域』,地方 / 〈C〉〈U〉(領海を含む)『領土』,領地 / 〈C〉〈U〉(セールスマン・代理店などの)『受け持ち区域』,担当区域;縄張り / 〈C〉〈U〉(学問などの)領域,分野 / 〈C〉《T-》(アメリカ・カナダなどの)準州

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/08/17 08:37:09」(JST)

The Universe is all of time and space and its contents.^[8]^[9]^[10]^[11] The Universe includes planets, stars, galaxies, the contents of intergalactic space, the smallest subatomic particles, and all matter and energy. The observable universe is about 28 billion parsecs (91 billion light-years) in diameter at the present time.^[2] The size of the whole Universe is not known and may be infinite.^[12] Observations and the development of physical theories have led to inferences about the composition and evolution of the Universe.

Throughout recorded history, cosmologies and cosmogonies, including scientific models, have been proposed to explain observations of the Universe. The earliest quantitative geocentric models were developed by ancient Greek philosophers and Indian philosophers.^[13]^[14] Over the centuries, more precise astronomical observations led to Nicolaus Copernicus's heliocentric model of the Solar System and Johannes Kepler's improvement on that model with elliptical orbits, which was eventually explained by Isaac Newton's theory of gravity. Further observational improvements led to the realization that the Solar System is located in a galaxy composed of billions of stars, the Milky Way. It was subsequently discovered that our galaxy is just one of many. Observations of the distribution of these galaxies and their spectral lines have led to many of the theories of modern physical cosmology. The discovery in the early 20th century that galaxies are systematically redshifted suggested that the Universe is expanding, and the discovery of the cosmic microwave background radiation suggested that the Universe had a beginning.^[15] Finally, observations in the late 1990s indicated the rate of the expansion of the Universe is increasing^[16] indicating that the majority of energy is most likely in an unknown form called dark energy.^[17]^[18] The majority of mass in the universe also appears to exist in an unknown form, called dark matter.^[17]^[18]

The Big Bang theory is the prevailing cosmological model describing the development of the Universe. Space and time were created in the Big Bang, and these were imbued with a fixed amount of energy and matter; as space expands, the density of that matter and energy decreases. After the initial expansion, the Universe cooled sufficiently to allow the formation first of subatomic particles and later of simple atoms. Giant clouds of these primordial elements later coalesced through gravity to form stars. Assuming that the prevailing model is correct, the age of the Universe is measured to be 7001137980000000000♠13.798±0.037 billion years.^[1]^[19]

There are many competing hypotheses about the ultimate fate of the Universe. Physicists and philosophers remain unsure about what, if anything, preceded the Big Bang. Many refuse to speculate, doubting that any information from any such prior state could ever be accessible. There are various multiverse hypotheses, in which some physicists have suggested that the Universe might be one among many universes that likewise exist.^[20]^[21]

1 Definition
2 Etymology
- 2.1 Synonyms
3 Chronology and the Big Bang
4 Properties
- 4.1 Shape
- 4.2 Size and regions
- 4.3 Age and expansion
- 4.4 Spacetime
5 Contents
- 5.1 Dark energy
- 5.2 Dark matter
- 5.3 Ordinary Matter
- 5.4 Particles
  - 5.4.1 Hadrons
  - 5.4.2 Leptons
  - 5.4.3 Bosons
  - 5.4.4 Photons
6 Geometry
7 Theories of physics
- 7.1 Special relativity
- 7.2 General relativity
  - 7.2.1 Model of the Universe based on general relativity
- 7.3 Multiverse hypothesis
- 7.4 Fine-tuned Universe
8 Historical development
- 8.1 Mythologies
- 8.2 Philosophical models
- 8.3 Astronomical concepts
9 See also
10 References

Definition

The Universe is customarily defined as everything that exists, everything that has existed, and everything that will exist.^[22]^[23]^[24] According to our current understanding, the Universe consists of three constituents: spacetime, forms of energy, including electromagnetic radiation and matter, and the physical laws that relate them. The Universe also encompasses all of life, all of history, and some philosophers and scientists even suggest that it encompasses ideas such as mathematics.^[25]^[26]^[27]

Etymology

The word universe derives from the Old French word univers, which in turn derives from the Latin word universum.^[28] The Latin word was used by Cicero and later Latin authors in many of the same senses as the modern English word is used.^[29] The Latin word derives from the poetic contraction unvorsum — first used by Lucretius in Book IV (line 262) of his De rerum natura (On the Nature of Things) — which connects un, uni (the combining form of unus, or "one") with vorsum, versum (a noun made from the perfect passive participle of vertere, meaning "something rotated, rolled, changed").^[29]

An alternative interpretation of unvorsum is "everything rotated as one" or "everything rotated by one". In this sense, it may be considered a translation of an earlier Greek word for the Universe, περιφορά, (periforá, "circumambulation"), originally used to describe a course of a meal, the food being carried around the circle of dinner guests.^[30] This Greek word refers to celestial spheres, an early Greek model of the Universe. Regarding Plato's Metaphor of the Sun, Aristotle suggests that the rotation of the sphere of fixed stars inspired by the prime mover,^[31] motivates, in turn, terrestrial change via the Sun. Astronomical and physical measurements, such as the Foucault pendulum, demonstrate that the Earth rotates on its axis.

Synonyms

A term for the Universe in ancient Greece was τὸ πᾶν (tò pán, The All, Pan). Related terms were matter, (τὸ ὅλον, tò hólon, see also Hyle, lit. wood) and place (τὸ κενόν, tò kenón).^[32]^[33] Other synonyms for the Universe among the ancient Greek philosophers included κόσμος (cosmos) and φύσις (meaning nature, Greek physis, from which we derive the word physics).^[34] The same synonyms are found in Latin authors (totum, mundus, natura)^[35] and survive in modern languages, e.g., the German words Das All, Weltall, and Natur for Universe. The same synonyms are found in English, such as everything (as in the theory of everything), the cosmos (as in cosmology), the world (as in the many-worlds interpretation), and nature (as in natural laws or natural philosophy).^[36]

Chronology and the Big Bang

Timeline of the Universe
In this diagram, time passes from left to right, and one dimension of space is suppressed, so at any given time, the Universe is represented by a disk-shaped "slice" of the diagram.

The prevailing model for the evolution of the Universe is the Big Bang theory.^[37]^[38] The Big Bang model states that the earliest state of the Universe was extremely hot and dense and that it subsequently expanded. The model is based on general relativity and on simplifying assumptions such as homogeneity and isotropy of space. A version of the model with a cosmological constant (Lambda) and cold dark matter, known as the Lambda-CDM model, is the simplest model that provides a reasonably good account of various observations about the Universe. The Big Bang model accounts for observations such as the correlation of distance and redshift of galaxies, the ratio of the number of hydrogen to helium atoms, and the microwave radiation background.

The initial hot, dense state is called the Planck epoch, a brief period extending from time zero to one Planck time unit of approximately 10⁻⁴³ seconds. During the Planck epoch, all types of matter and all types of energy were concentrated into a dense state, where gravitation is believed to have been as strong as the other fundamental forces, and all the forces may have been unified. Since the Planck epoch, the Universe has been expanding to its present form, possibly with a very brief period (less than 10⁻³² seconds) of cosmic inflation which caused the Universe to reach a much larger size almost instantaneously.^[39]

After the Planck epoch and inflation came the quark, hadron, and lepton epochs. Together, these epochs encompassd less than 10 seconds of time following the Big Bang. Other observations ^{[clarification needed]} can be explained by combining the overall expansion of space with nuclear and atomic physics. As the Universe expands, the energy density of electromagnetic radiation decreases more quickly than does that of matter because the energy of a photon decreases with its wavelength. As the Universe expanded and cooled, elementary particles associated stably into ever larger combinations. Thus, in the early part of the matter-dominated era, stable protons and neutrons formed, which then associated into atomic nuclei. At this stage, matter in the Universe was mainly a hot, dense plasma of negatively charged electrons, neutral neutrinos and positive nuclei. This era, called the photon epoch, lasted about 380 thousand years. Nuclear reactions among nuclei led to the present abundances of lighter nuclei, particularly hydrogen, deuterium, and helium through a process known as Big Bang nucleosynthesis.

Eventually, at time known as recombination, electrons and nuclei formed stable atoms, which are transparent to most wavelengths of radiation. With photons decoupled from matter, the Universe entered the matter-dominated era. Light from this era could now travel freely, and it can still be seen in the Universe as the cosmic microwave background (CMB). After around 100 million years, the first stars formed; these were likely very massive, luminous, and responsible for the reionization of the Universe. Having no elements heavier than lithium, these stars also produced the first heavy elements through stellar nucleosynthesis.^[40] The Universe also contains a mysterious energy called dark energy; the energy density of dark energy does not change over time. After about 9.8 billion years, the Universe had expanded sufficiently so that the density of matter was less than the density of dark energy, marking the beginning of the present dark-energy-dominated era.^[41] In this era, the expansion of the Universe is accelerating due to dark energy.

Properties

The spacetime of the Universe is usually interpreted from a Euclidean perspective, with space as consisting of three dimensions, and time as consisting of one dimension, the "fourth dimension". By combining space and time into a single manifold called Minkowski space, physicists have simplified a large number of physical theories, as well as described in a more uniform way the workings of the Universe at both the supergalactic and subatomic levels.

The four dimensions of spacetime consist of events that are not absolutely defined spatially and temporally, but rather are known relative to the motion of an observer. Minkowski space first approximates the Universe without gravity; the pseudo-Riemannian manifolds of general relativity describe spacetime with matter and gravity. Some areas of theoretical physics, such as string theory, postulate the existence of additional dimensions.

Of the four fundamental interactions, gravitation is dominant at cosmological length scales; that is, the other three forces play a negligible role in determining structures at the level of galaxies and larger-scale structures. Gravity's effects are cumulative; by contrast, the effects of positive and negative charges tend to cancel one another, making electromagnetism relatively insignificant on cosmological length scales. The remaining two interactions, the weak and strong nuclear forces, decline very rapidly with distance; their effects are confined mainly to sub-atomic length scales.

The Universe appears to have much more matter than antimatter, an asymmetry possibly related to the observations of CP violation.^[42] The Universe appears to have no net electric charge, and therefore gravity appears to be the dominant interaction on cosmological length scales. The Universe also appears to have neither net momentum nor angular momentum. The absence of net charge and momentum would follow from accepted physical laws (Gauss's law and the non-divergence of the stress-energy-momentum pseudotensor, respectively), if the Universe were finite.^[43]

Constituent spatial scales of the observable universe

Shape

The three possible options of the shape of the Universe.

The shape of the Universe is related to general relativity, which describes how spacetime is curved and bent by mass and energy. The curvature, topology or geometry of the Universe includes both local geometry in the observable universe and global geometry, which is possibly measurable. Investigations include, which 3-manifold corresponds to the spatial section in comoving coordinates of the four-dimensional spacetime of the Universe.

Cosmologists often work with a given space-like slice of spacetime called the comoving coordinates. In terms of observation, the section of spacetime that can be observed is the backward light cone, being the time it takes to reach a given observer within the cosmological horizon (particle horizon).

The particle horizon, the light horizon, or the cosmic light horizon, is the maximum distance from which particles can have traveled to the observer in the age of the Universe. An horizon represents the boundary between the observable and the unobservable region of the Universe.^[44]^[45] The existence, properties, and significance of a cosmological horizon depend on the particular cosmological model.

Observational data suggest the cosmological topological of the Universe is infinite in extent with finite age, supported by the so-called Friedmann–Lemaître–Robertson–Walker (FLRW) models.^[46]^[47]^[48]^[49] These FLRW models of space are consistent with the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck maps of cosmic background radiation, thus supporting inflationary models and the standard model of cosmology, describing a flat, homogeneous universe dominated by dark matter and dark energy.^[1]^[50]

Size and regions

According to a restrictive definition, the Universe is everything within our connected spacetime that could have a chance to interact with us and vice versa.^[51] According to the general theory of relativity, some regions of space may never interact with ours even in the lifetime of the Universe due to the finite speed of light and the ongoing expansion of space. For example, radio messages sent from Earth may never reach some regions of space, even if the Universe were to exist forever: space may expand faster than light can traverse it.^[52] Since we cannot observe space beyond the limitations of light, or any electromagnetic radiation, it is unknown whether the size of the Universe is finite or infinite.^[12]^[53]^[54]

Distant regions of space are taken to exist and be part of reality as much as we are, yet we can never interact with them. The spatial region within which we can affect and be affected is the observable universe. The observable Universe depends on the location of the observer. By traveling, an observer can come into contact with a greater region of spacetime than an observer who remains still. Nevertheless, even the most rapid traveler will not be able to interact with all of space. Typically, the observable Universe is taken to mean the Universe observable from our vantage point in the Milky Way Galaxy.

The proper distance – the distance as would be measured at a specific time, including the present – between Earth and the edge of the observable universe is 46 billion light-years (14×10^⁹ pc), making the diameter of the observable universe about 91 billion light-years (28×10^⁹ pc). The distance the light from the edge of the observable universe has travelled is very close to the age of the Universe times the speed of light, 13.8 billion light-years (4.2×10^⁹ pc), but this does not represent the distance at any given time because the edge of the universe and the Earth have moved since further apart.^[55] For comparison, the diameter of a typical galaxy is 30,000 light-years, and the typical distance between two neighboring galaxies is 3 million light-years.^[56] As an example, the Milky Way Galaxy is roughly 100,000 light years in diameter,^[57] and the nearest sister galaxy to the Milky Way, the Andromeda Galaxy, is located roughly 2.5 million light years away.^[58]

Age and expansion

Astronomers calculate the age of the Universe by assuming that the Lambda-CDM model accurately describes the evolution of the Universe from a very uniform, hot, dense primordial state to its present state and measuring the cosmological parameters which constitute the model. This model is well understood theoretically and supported by recent high-precision astronomical observations such as WMAP and Planck. Commonly, the set of observations fitted includes the cosmic microwave background anisotropy, the brightness/redshift relation for Type Ia supernovae, and large-scale galaxy clustering including the baryon acoustic oscillation feature. Other observations, such as the Hubble constant, the abundance of galaxy clusters, weak gravitational lensing and globular cluster ages, are generally consistent with these, providing a check of the model, but are less accurately measured at present. With the prior that the Lambda-CDM model is correct and the values of the parameters measured by various experiments including Planck, the best value of the age of the Universe as of 2015 is 13.798 ± 0.037 billion years.^[1]

Over time, the Universe and its contents have evolved; for example, the relative population of quasars and galaxies has changed^[59] and space itself has expanded. This expansion accounts for how it is that scientists on Earth can observe the light from a galaxy 30 billion light years away, even if that light has traveled for only 13 billion years; the very space between them has expanded, and that is one of the tools used to calculate the age of the Universe. This expansion is consistent with the observation that the light from distant galaxies has been redshifted; the photons emitted have been stretched to longer wavelengths and lower frequency during their journey. Analyses of Type Ia supernovae indicate that the spatial expansion is accelerating.^[60]^[61]

The more matter there is in the Universe, the stronger will be the gravitational pull among the matter. If the Universe were too dense then it would re-collapse into singularity. However, if the Universe contained too little matter then the expansion is accelerated greatly, thereby leaving no time for planets and planetary systems to form. After the Big Bang, the universe is continuously expanding. The rate of expansion is affected by the gravity among the matter present. Surprisingly, our universe has just the right mass density of about 5 protons per cubic meter which has allowed it to expand for last 13.8 billion years, giving time to form the universe as we see it today.^[62]

There are dynamical forces acting on the particles in the Universe which affect the expansion rate. It was earlier expected that the Hubble Constant would be decreasing as time went on due to the influence of gravitational interactions in the Universe, and thus there is an additional observable quantity in the Universe called the deceleration parameter which cosmologists expected to be directly related to the matter density of the Universe. Surprisingly, the deceleration parameter was measured by two different groups to be less than zero (actually, consistent with −1) which implied that today Hubble's Constant is increasing as time goes on. Some cosmologists have whimsically called the effect associated with the "accelerating universe" the "cosmic jerk".^[63] The 2011 Nobel Prize in Physics was given for the discovery of this phenomenon.^[64]

Spacetime

Spacetimes are the arenas in which all physical events take place—an event is a point in spacetime specified by its time and place. For example, the motion of planets around the sun may be described in a particular type of spacetime, or the motion of light around a rotating star may be described in another type of spacetime. The basic elements of spacetime are events. In any given spacetime, an event is a unique position at a unique time. Because events are spacetime points, an example of an event in classical relativistic physics is , the location of an elementary (point-like) particle at a particular time. A spacetime itself can be viewed as the union of all events in the same way that a line is the union of all of its points, formally organized into a manifold, a space which can be described at small scales using coordinate systems.

The Universe appears to be a smooth spacetime continuum consisting of three spatial dimensions and one temporal (time) dimension. On the average, space is observed to be very nearly flat (close to zero curvature), meaning that Euclidean geometry is empirically true with high accuracy throughout most of the Universe.^[65] Spacetime also appears to have a simply connected topology, in analogy with a sphere, at least on the length-scale of the observable Universe. However, present observations cannot exclude the possibilities that the Universe has more dimensions and that its spacetime may have a multiply connected global topology, in analogy with the cylindrical or toroidal topologies of two-dimensional spaces.^[47]^[66]

The Universe is composed almost completely of dark energy, dark matter, and ordinary matter. Other contents are electromagnetic radiation(estimated to be from 0.005% to close to 0.01%,) and antimatter.^[67]^[68]^[69] The total amount of electromagnetic radiation generated within the universe has decreased by 1/2 in the past 2 billion years, indicating no electromagnetic radiation will be generated in the distant future as the universe ages.^[70]^[71]^[72]

Ordinary baryonic matter, which includes atoms, stars, galaxies, and life, is only 4.6% of the contents. The present overall density of this type of matter is very low, roughly 4.5 × 10⁻³¹ grams per cubic centimetre, corresponding to a density of the order of only one proton for every four cubic meters of volume.^[4] The nature of both dark energy and dark matter is unknown. Dark matter, a mysterious form of matter that has not yet been identified, is 26.8% of the contents. Dark energy, which is the energy of empty space and that is causing the expansion of the Universe to accelerate, is the remaining 68.3% of the contents.^[6]^[73]^[74]

A map of the Superclusters and voids nearest to Earth

Matter, dark matter, and dark energy are distributed homogeneously throughout the Universe over length scales longer than 300 million light-years or so.^[75] However, on smaller length-scales, matter is observed to clump hierarchically; many atoms are condensed into stars, most stars into galaxies, most galaxies into clusters, superclusters and, finally, the largest-scale structures such as the Sloan great wall. There are probably more than 100 billion (10¹¹) galaxies in the observable Universe.^[76] Typical galaxies range from dwarfs with as few as ten million^[77] (10⁷) stars up to giants with one trillion^[78] (10¹²) stars. A 2010 study by astronomers estimated that the observable Universe contains 300 sextillion (3×10²³) stars.^[79] Between the structures are voids, which are typically 10–150 Mpc (33 million–490 million ly) in diameter. The Milky Way is in the Local Group of galaxies, which in turn is in the Laniakea Supercluster.^[80] This supercluster spans over 500 million light years, while the Local Group spans over 10 million light years.^[81] In April 2015, astronomers announced the discovery of a supervoid, the largest known structure in the universe. This big hole is 1.8 billion ly (550 Mpc) across, characterized by its unusual emptiness.^[82]

Contents of the Universe updated with WMAP 9-YEAR RESULTS^[83]^[84] ^{as of} ^04-08-2013

Contents of the Universe comparison today to the early Universe.^[85] ^{As of} ^04-08-2013 ^m^{ade with 5 year WMAP data.} ^{WMAP data is accurate to two digits, the total of these numbers is not 100%. This reflects the current limits of WMAP's ability to define Dark Matter and Dark Energy. Electromagnetic radiation, antimatter and other contents are not included.}

The observable matter of the Universe is also isotropic on large scales, meaning that no direction of observation appears to be different from any other.^[86] The Universe is also bathed in a highly isotropic microwave radiation that corresponds to a thermal equilibrium blackbody spectrum of roughly 2.725 kelvin.^[87] The hypothesis that the large-scale Universe is homogeneous and isotropic is known as the cosmological principle,^[88] which is supported by astronomical observations.

Dark energy

An explanation for why the expansion of the Universe is accelerating remains elusive. It is often attributed to "dark energy", an unknown form of energy that is hypothesized to permeate space.^[73] On a mass–energy equivalence basis, the density of dark energy (6.91 × 10⁻²⁷ kg/m³) is much less than the density of ordinary matter or dark matter within galaxies. However, in the present dark-energy era, it dominates the mass–energy of the universe because it is uniform across space.^[89]

Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously,^[90] and scalar fields such as quintessence or moduli, dynamic quantities whose energy density can vary in time and space. Contributions from scalar fields that are constant in space are usually also included in the cosmological constant. The cosmological constant can be formulated to be equivalent to vacuum energy. Scalar fields having only a slight amont of spatial inhomogeneity can be difficult to distinguish from a cosmological constant.

Dark matter

Dark matter is a hypothetical kind of matter that cannot be seen with telescopes, but which accounts for most of the matter in the Universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the Universe. Other than neutrinos, a form of hot dark matter, dark matter has not been detected directly, making it one of the greatest mysteries in modern astrophysics. Dark matter neither emits nor absorbs light or any other electromagnetic radiation at any significant level. Dark matter is estimated to constitute 26.8% of the total mass–energy and 84.5% of the total matter in the Universe.^[6]^[91]

Ordinary Matter

The remaining 4.9% of the mass–energy of the Universe is composed of matter made up of ordinary matter, that is atoms, ions, electrons and the objects they form. This matter includes stars, which produce nearly all of the light we see from galaxies, as well as interstellar gas in the interstellar and intergalactic media, planets, and all the objects from everyday life that we can bump into, touch or squeeze.^[92]

Ordinary matter commonly exists in four states (or phases): solid, liquid and gas, and plasma. However, advances in experimental techniques have revealed other previously theoretical phases, such as Bose–Einstein condensates and fermionic condensates.

More fundamentally, matter is composed of two types of elementary particles: quarks and leptons.^[93] For example, the neutron is formed of two down quarks and one up quark, while the proton is formed of two up quarks and one down quark. Atoms are made up of several neutrons and protons (two types of baryons), which have several electrons (a type of lepton) orbiting them. Because most of the mass of the atom is concentrated in the atomic nucleus, which is made up of baryons, astronomers often use the term baryonic matter to describe ordinary matter, although a small fraction of this baryonic matter is also composed of electrons. A focus on an elementary-particle view of matter also leads to new phases of matter, such as the quark–gluon plasma.^[94]

The primordial protons and neutrons themselves were formed from the quark–gluon plasma during the Big Bang as it cooled below two trillion degrees. A few minutes afterwards, starting with only protons and neutrons, nuclei up to lithium and beryllium were formed, but the abundances of other elements dropped sharply with growing atomic mass. Some boron may have been formed at this time, but the process stopped before significant carbon could be formed. This process, known as Big Bang nucleosynthesis, essentially shut down after about 20 minutes, due to drops in temperature and density as the universe continued to expand. The subsequent nucleosynthesis of heavier elements required the extreme temperatures and pressures found within stars and supernovas, in the processes of stellar nucleosynthesis and supernova nucleosynthesis.

Particles

The tree-level interactions between elementary particles described in the Standard Model.

Six of the particles in the Standard Model are quarks (shown in purple). Each of the first three columns forms a generation of matter.^{[clarification needed (Other particles are not explained)]}

The ordinary matter in the Universe consists of particles described by particle physics. An elementary particle or fundamental particle is a particle whose substructure (domain of the bigger structure which shares the similar characteristics of the domain) is unknown, thus it is unknown whether it is composed of other particles.^[95] Known elementary particles include the fundamental fermions (quarks, leptons, antiquarks, and antileptons), which generally are "matter particles" and "antimatter particles", as well as the fundamental bosons (gauge bosons and Higgs boson), which generally are "force particles" that mediate interactions among fermions.^[95] A particle containing two or more elementary particles is a composite particle.

The Standard Model of particle physics suggests a universal set of physical laws and physical constants.^[96] It concerns the electromagnetic, weak, and strong nuclear interactions, as well as classifying all the subatomic particles known. It was developed throughout the latter half of the 20th century as a collaborative effort of scientists around the world.^[97] The current formulation was finalized in the mid-1970s upon experimental confirmation of the existence of quarks. Since then, discoveries of the top quark (1995), the tau neutrino (2000), and more recently the Higgs boson (2013), have given further credence to the Standard Model. Because of its success in explaining a wide variety of experimental results, the Standard Model is sometimes regarded as a "theory of almost everything".

Each particle generation is divided into two types of leptons and two types of quarks, both of which are fermions. Bosons are the other fundamental class of elementary particles. Additionally, there are hypothetical particles.

Hadrons

A hadron is a composite particle made of quarks bound state by the strong force (in a similar way as molecules are held together by the electromagnetic force). From approximately 10⁻⁶ seconds after the Big Bang, when the temperature of the universe had fallen sufficiently to allow the quarks from the preceding quark epoch to bind together into hadrons, the mass of the universe was dominated by hadrons. This period is known as the hadron epoch. Initially the temperature was high enough to allow the formation of hadron/anti-hadron pairs, which kept matter and antimatter in thermal equilibrium. However, as the temperature of the Universe continued to fall, hadron/anti-hadron pairs were no longer produced. Most of the hadrons and anti-hadrons were then eliminated in annihilation reactions, leaving a small residual of hadrons. The elimination of anti-hadrons was completed by one second after the Big Bang, when the following lepton epoch began.

Hadrons are categorized into two families: baryons (such as protons and neutrons) made of three quarks and mesons (such as pions) made of one quark and one antiquark. Of the hadrons, protons are stable, and neutrons are bound within atomic nuclei are stable. Other hadrons are unstable under ordinary conditions; free neutrons decay with a half-life of about 611 seconds. Experimentally, hadron physics is studied by colliding protons or nuclei of heavy elements such as lead, and detecting the debris in the produced particle showers.

Leptons

A lepton is an elementary, half-integer spin (spin ¹⁄₂) particle that does not undergo strong interactions but is subject to the Pauli exclusion principle; no two leptons of the same species can be in exactly the same state at the same time.^[98] Fermions differ from bosons, which obey Bose–Einstein statistics. The best known of all leptons is the electron, which governs nearly all of chemistry as it is found in atoms and is directly tied to all chemical properties. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons), and neutral leptons (better known as neutrinos). The two leptons may be classified into one with electric charge −1 (electron-like) and one neutral (neutrino). Thus electrons are stable and the most common charged lepton in the Universe, whereas muons and taus can only be produced in high energy collisions (such as those involving cosmic rays and those carried out in particle accelerators).^[99]^[100] Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. Neutrinos of all generations stream throughout the Universe but rarely interact with normal matter.^[101]

The lepton epoch was the period in the evolution of the early Universe in which the leptons dominated the mass of the Universe. It started roughly 1 second after the Big Bang, after the majority of hadrons and anti-hadrons annihilated each other at the end of the hadron epoch. During the lepton epoch the temperature of the Universe was still high enough to create lepton/anti-lepton pairs, so leptons and anti-leptons were in thermal equilibrium. Approximately 10 seconds after the Big Bang, the temperature of the Universe had fallen to the point where lepton/anti-lepton pairs were no longer created.^[102] Most leptons and anti-leptons were then eliminated in annihilation reactions, leaving a small residue of leptons. The mass of the Universe was then dominated by photons as it entered the following photon epoch.

Leptons have various intrinsic properties, including electric charge, spin, and mass. Unlike quarks however, leptons are not subject to the strong interaction, but they are subject to the other three fundamental interactions: gravitation (best described at present by general relativity), electroweak (includes electromagnetism), and the weak interaction. During the quark epoch, the electroweak force split into the electromagnetic and weak forces. Interactions can be described by renormalized quantum field theory, and are mediated by gauge bosons that correspond to a particular type of gauge symmetry. A renormalized quantum field theory of general relativity has not yet been achieved.

Bosons

Bosons may be either elementary, like photons, or composite, like mesons. Bosons are characterized by Bose–Einstein statistics and all have integer spins. While most bosons are composite particles, and these are important in superfluidity and other applications of Bose–Einstein condensates, in the Standard Model there are five bosons which are elementary: photons, which carry the electromagnetic interaction; W and Z bosons, which carry the weak interaction; gluons, which carry the strong interaction, and the scalar boson Higgs Boson.^[103] Additionally, the graviton is a hypothetical elementary particle not incorporated in the Standard Model. If it exists, a graviton must be a boson, and could conceivably be a gauge boson.

The Higgs boson or Higgs particle is an elementary particle in the Standard Model. Observations of the particle allows scientists to explore the Higgs field^[104]^[105]—a fundamental field of crucial importance to particle physics theory, that unlike the more familiar electromagnetic field cannot be "turned off", but instead takes a non-zero constant value almost everywhere.^[105] The presence of this field, now believed to be confirmed, explains why some fundamental particles have mass even though the symmetries controlling their interactions should require them to be massless, and also answers several other long-standing puzzles in physics, such as the reason the weak force has a much shorter range than the electromagnetic force. The Higgs field can be detected through its excitations (i.e. Higgs particles), but these are extremely hard to produce and detect.

Photons

A photon is an elementary particle, the quantum of light and all other forms of electromagnetic radiation. It is the force carrier for the electromagnetic force, even when static via virtual photons. The effects of this force are easily observable at the microscopic and at the macroscopic level because the photon has zero rest mass; this allows long distance interactions. Like all elementary particles, photons are currently best explained by quantum mechanics and exhibit wave–particle duality, exhibiting properties of waves and of particles. For example, a single photon may be refracted by a lens or exhibit wave interference with itself but also act as a particle giving a definite result when its position is measured.

In the Standard Model, the photon is one of four gauge bosons in the electroweak interaction; the other three are denoted W⁺, W⁻ and Z⁰ and are responsible for the weak interaction. Unlike the photon, these gauge bosons have mass, owing to a mechanism that breaks their SU(2) gauge symmetry.

The photon epoch started after most leptons and anti-leptons were annihilated at the end of the lepton epoch, about 10 seconds after the Big Bang. Atomic nuclei were created in the process of nucleosynthesis which occurred during the first few minutes of the photon epoch. For the remainder of the photon epoch the universe contained a hot dense plasma of nuclei, electrons and photons. About 380,000 years after the Big Bang the temperature of the universe fell to the point where nuclei could combine with electrons to create neutral atoms. As a result, photons no longer interacted frequently with matter, the universe became transparent and the cosmic microwave background radiation was created and then structure formation took place.

In the Standard Model, photons and other elementary particles are described as a necessary consequence of physical laws having a certain symmetry at every point in spacetime. The intrinsic properties of particles, such as electric charge, mass and spin, are determined by the properties of this gauge symmetry.

Geometry

High-precision test of general relativity by the Cassini space probe (artist's impression): radio signals sent between the Earth and the probe (green wave) are delayed by the warping of space and time (blue lines) due to the Sun's mass.

In modern physics, space and time are unified in a four-dimensional Minkowski continuum (a single interwoven continuum) called Spacetime, with the goal to create a phase space (dynamical system in which all possible states of a system are represented), whose metric treats the time dimension differently from the three spatial dimensions.

The geometry of 4-dimensional space is much more complex than that of 3-dimensional space, due to the extra degree of freedom (time, t). The set of points in Euclidean 4-space having the same distance R from a fixed point P₀ forms a hypersurface known as a 3-sphere (see also Hypersphere). The hypervolume of the enclosed space can be calculated with:

This is part of the Friedmann–Lemaître–Robertson–Walker metric in General relativity where R is substituted by function R(t) with t meaning the cosmological age of the universe. Growing or shrinking R with time means expanding or collapsing universe, depending on the mass density inside.^[106] Thus, after the singularity, space begun to expand, and models try to recapture past and future evolution of the Universe, and to understand the fundamental principles at work.

Theories of physics

Special relativity

Special relativity is the generally accepted physical theory regarding the relationship between space and time. It is based on two postulates: (1) that the laws of physics are invariant (i.e. identical) in all inertial systems (non-accelerating frames of reference); and (2) that the speed of light in a vacuum is the same for all observers, regardless of the motion of the light source. It was originally proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".^[107] The inconsistency of Newtonian mechanics with Maxwell’s equations of electromagnetism and the inability to discover Earth's motion through a luminiferous aether led to the development of special relativity, which corrects mechanics to handle situations involving motions nearing the speed of light. As of today, special relativity is the most accurate model of motion at any speed. Even so, Newtonian mechanics is still useful (due to its simplicity and high accuracy) as an approximation at small velocities relative to the speed of light.

Special relativity implies a wide range of consequences, which have been experimentally verified,^[108] including length contraction, time dilation, relativistic mass, mass–energy equivalence, a universal speed limit, and relativity of simultaneity. It has replaced the conventional notion of an absolute universal time with the notion of a time that is dependent on reference frame and spatial position. Rather than an invariant time interval between two events, there is an invariant spacetime interval. Combined with other laws of physics, the two postulates of special relativity predict the equivalence of mass and energy, as expressed in the mass–energy equivalence formula E = mc², where c is the speed of light in vacuum.^[109]^[110]

A defining feature of special relativity is the replacement of the Galilean transformations of Newtonian mechanics with the Lorentz transformations. Time and space cannot be defined separately from each other. Rather space and time are interwoven into a single continuum known as spacetime. Events that occur at the same time for one observer could occur at different times for another.

General relativity

General relativity is the geometric theory of gravitation published by Albert Einstein in 1915^[111] and the current description of gravitation in modern physics. It is the basis of current cosmological models of a consistently expanding universe. General relativity generalizes special relativity and Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time, or spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of partial differential equations.

Some predictions of general relativity differ significantly from those of classical physics, especially concerning the passage of time, the geometry of space, the motion of bodies in free fall, and the propagation of light. Examples of such differences include gravitational time dilation, gravitational lensing, the gravitational redshift of light, and the gravitational time delay. The predictions of general relativity have been confirmed in all observations and experiments to date. Although general relativity is not the only relativistic theory of gravity, it is the simplest theory that is consistent with experiments and observations. However, unanswered questions remain, the most fundamental being how general relativity can be reconciled with the laws of quantum physics to produce a complete and self-consistent theory of quantum gravity.

Model of the Universe based on general relativity

In general relativity, the distribution of matter and energy determines the geometry of spacetime, which in turn describes the acceleration of matter. Therefore, solutions of the Einstein field equations describe the evolution of the Universe. Combined with measurements of the amount, type, and distribution of matter in the Universe, the equations of general relativity describe the evolution of the Universe over time.^[112]

With the assumption of the cosmological principle that the Universe is homogeneous and isotropic everywhere, a specific solution of the field equations that describes the Universe is the metric tensor called the Friedmann–Lemaître–Robertson–Walker metric,

ds^2 = -c^{2} dt^2 + R(t)^2 \left( \frac{dr^2}{1-k r^2} + r^2 d\theta^2 + r^2 \sin^2 \theta \, d\phi^2 \right)

where (r, θ, φ) correspond to a spherical coordinate system. This metric has only two undetermined parameters. An overall length scale R describes the size scale of the Universe as a function of time; an increase in R is the expansion of the Universe. A curvature index k describes the geometry. The index k can be only 0, corresponding to flat Euclidean geometry, 1, corresponding to a space of positive curvature, or −1, a space of positive or negative curvature. In cosmology, solving for the history of the Universe is done by calculating R as a function of time t, given k and the value of the cosmological constant Λ.^[112] The cosmological constant represents the energy density of the vacuum of space and could be related to dark energy.^[73] The equation describing how R varies with time is known as the Friedmann equation after its inventor, Alexander Friedmann.^[113]

The solutions for R(t) depend on k and Λ, but some qualitative features of such solutions are general. First and most importantly, the length scale R of the Universe can remain constant only if the Universe is perfectly isotropic with positive curvature (k=1) and has one precise value of density everywhere, as first noted by Albert Einstein.^[112] However, this equilibrium is unstable and because the Universe is known to be inhomogeneous on smaller scales, R must change, according to general relativity. When R changes, all the spatial distances in the Universe change in tandem; there is an overall expansion or contraction of space itself. This accounts for the observation that galaxies appear to be flying apart; the space between them is stretching. The stretching of space also accounts for the apparent paradox that two galaxies can be 40 billion light years apart, although they started from the same point 13.8 billion years ago^[114] and never moved faster than the speed of light.

Second, all solutions suggest that there was a gravitational singularity in the past, when R goes to zero and matter and energy became infinitely dense. It may seem that this conclusion is uncertain because it is based on the questionable assumptions of perfect homogeneity and isotropy (the cosmological principle) and that only the gravitational interaction is significant. However, the Penrose–Hawking singularity theorems show that a singularity should exist for very general conditions. Hence, according to Einstein's field equations, R grew rapidly from an unimaginably hot, dense state that existed immediately following this singularity (when R had a small, finite value); this is the essence of the Big Bang model of the Universe.

Third, the curvature index k determines the sign of the mean spatial curvature of spacetime averaged over sufficiently large length scales (greater than about a billion light years). If k=1, the curvature is positive and the Universe has a finite volume. Such universes are often visualized as a three-dimensional sphere 3-sphere embedded in a four-dimensional space. Conversely, if k is zero or negative, the Universe may have infinite volume, depending on its overall topology. It may seem counter-intuitive that an infinite and yet infinitely dense Universe could be created in a single instant at the Big Bang when R=0, but exactly that is predicted mathematically when k does not equal 1. For comparison, an infinite plane has zero curvature but infinite area, whereas an infinite cylinder is finite in one direction and a torus is finite in both. A toroidal Universe could behave like a normal Universe with periodic boundary conditions.

The ultimate fate of the Universe is still unknown, because it depends critically on the curvature index k and the cosmological constant Λ. If the Universe were sufficiently dense, k would equal +1, meaning that its average curvature throughout is positive and the Universe will eventually recollapse in a Big Crunch, possibly starting a new Universe in a Big Bounce. Conversely, if the Universe were insufficiently dense, k would equal 0 or −1 and the Universe would expand forever, cooling off and eventually reaching the Big Freeze and the heat death of the Universe.^[112] Modern data suggests that the expansion speed of the Universe is not decreasing as originally expected, but increasing; if this continues indefinitely, the Universe may eventually reach a Big Rip. Observationally, the Universe appears to be flat (k = 0), with an overall density that is very close to the critical value between recollapse and eternal expansion.

Multiverse hypothesis

Depiction of a multiverse of seven "bubble" universes, which are separate spacetime continua, each having different physical laws, physical constants, and perhaps even different numbers of dimensions or topologies.

Some speculative theories have proposed that our Universe is but one of a set of disconnected universes, collectively denoted as the multiverse, challenging or enhancing more limited definitions of the Universe.^[20]^[115] Scientific multiverse models are distinct from concepts such as alternate planes of consciousness and simulated reality.

Max Tegmark developed a four-part classification scheme for the different types of multiverses that scientists have suggested in various problem domains. An example of such a model is the chaotic inflation model of the early universe.^[116] Another is the many-worlds interpretation of quantum mechanics. Parallel worlds are generated in a manner similar to quantum superposition and decoherence, with all states of the wave function being realized in separate worlds. Effectively, the multiverse evolves as a universal wavefunction. If the Big Bang that created our multiverse created an ensemble of multiverses, the wave function of the ensemble would be entangled in this sense.

The least controversial category of multiverse in Tegmark's scheme is Level I, which describes distant spacetime events "in our own universe", but suggests that statistical analysis exploiting the anthropic principle provides an opportunity to test multiverse theories in some cases. If space is infinite, or sufficiently large and uniform, identical instances of the history of Earth's entire Hubble volume occur every so often, simply by chance. Tegmark calculated our nearest so-called doppelgänger, is 10^10¹¹⁵ meters away from us (a double exponential function larger than a googolplex).^[117]^[118] In principle, it would be impossible to scientifically verify an identical Hubble volume. However, it does follow as a fairly straightforward consequence from otherwise unrelated scientific observations and theories.

It is possible to conceive of disconnected spacetimes, each existing but unable to interact with one another.^[117]^[119] An easily visualized metaphor is a group of separate soap bubbles, in which observers living on one soap bubble cannot interact with those on other soap bubbles, even in principle.^[120] According to one common terminology, each "soap bubble" of spacetime is denoted as a universe, whereas our particular spacetime is denoted as the Universe,^[20] just as we call our moon the Moon. The entire collection of these separate spacetimes is denoted as the multiverse.^[20] With this terminology, different Universes are not causally connected to each other.^[20] In principle, the other unconnected Universes may have different dimensionalities and topologies of spacetime, different forms of matter and energy, and different physical laws and physical constants, although such possibilities are purely speculative.^[20] Others consider each of several bubbles created as part of chaotic inflation to be separate Universes, though in this model these universes all share a causal origin.^[20]

Fine-tuned Universe

The fine-tuned Universe is the proposition that the conditions that allow life in the Universe can only occur when certain universal fundamental physical constants lie within a very narrow range, so that if any of several fundamental constants were only slightly different, the Universe would be unlikely to be conducive to the establishment and development of matter, astronomical structures, elemental diversity, or life as it is understood.^[121] The proposition is discussed among philosophers, scientists, theologians, and proponents and detractors of creationism.

Historical development

Historically, there have been many ideas of the cosmos (cosmologies) and its origin (cosmogonies). Theories of an impersonal Universe governed by physical laws were first proposed by the Greeks and Indians.^[14] Ancient Chinese philosophy encompassed the notion of the Universe including both all of space and all of time.^[122]^[123] Over the centuries, improvements in astronomical observations and theories of motion and gravitation led to ever more accurate descriptions of the Universe. The modern era of cosmology began with Albert Einstein's 1915 general theory of relativity, which made it possible to quantitatively predict the origin, evolution, and conclusion of the Universe as a whole. Most modern, accepted theories of cosmology are based on general relativity and, more specifically, the predicted Big Bang.^[124]

Mythologies

Many cultures have stories describing the origin of the world and universe. Cultures generally regard these stories as having some truth.^[125] There are however many differing beliefs in how these stories apply amongst those believing in a supernatural origin, ranging from a god directly creating the Universe as it is now to a god just setting the "wheels in motion" (for example via mechanisms such as the big bang and evolution).^{[citation needed]}

Creation stories may be roughly grouped into common types. In one type of story, the world is born from a world egg; such stories include the Finnish epic poem Kalevala, the Chinese story of Pangu or the Indian Brahmanda Purana. In related stories, the Universe is created by a single entity emanating or producing something by him- or herself, as in the Tibetan Buddhism concept of Adi-Buddha, the ancient Greek story of Gaia (Mother Earth), the Aztec goddess Coatlicue myth, the ancient Egyptian god Atum story, and the Judeo-Christian Genesis creation narrative in which the Abrahamic God created the Universe. In another type of story, the Universe is created from the union of male and female deities, as in the Maori story of Rangi and Papa. In other stories, the Universe is created by crafting it from pre-existing materials, such as the corpse of a dead god — as from Tiamat in the Babylonian epic Enuma Elish or from the giant Ymir in Norse mythology – or from chaotic materials, as in Izanagi and Izanami in Japanese mythology. In other stories, the Universe emanates from fundamental principles, such as Brahman and Prakrti, the creation myth of the Serers,^[126] or the yin and yang of the Tao.

Philosophical models

The pre-Socratic Greek philosophers and Indian philosophers developed some of the earliest philosophical concepts of the Universe.^[14]^[127] The earliest Greek philosophers noted that appearances can be deceiving, and sought to understand the underlying reality behind the appearances. In particular, they noted the ability of matter to change forms (e.g., ice to water to steam) and several philosophers proposed that all the physical materials in the world are different forms of a single primordial material, or arche. The first to do so was Thales, who proposed this material is water. Thales' student, Anaximander, proposed that everything came from the limitless apeiron. Anaximenes proposed air on account of its perceived attractive and repulsive qualities that cause the arche to condense or dissociate into different forms. Anaxagoras proposed the principle of Nous (Mind). Heraclitus proposed fire (and spoke of logos). Empedocles proposed the elements: earth, water, air and fire. His four-element model became very popular. Like Pythagoras, Plato believed that all things were composed of number, with Empedocles' elements taking the form of the Platonic solids. Democritus, and later philosophers—most notably Leucippus—proposed that the Universe is composed of indivisible atoms moving through void (vacuum). Aristotle did not believe that was feasible because air, like water, offers resistance to motion. Air will immediately rush in to fill a void, and moreover, without resistance, it would do so indefinitely fast.

Although Heraclitus argued for eternal change, his contemporary Parmenides made the radical suggestion that all change is an illusion, that the true underlying reality is eternally unchanging and of a single nature. Parmenides denoted this reality as τὸ ἐν (The One). Parmenides' idea seemed implausible to many Greeks, but his student Zeno of Elea challenged them with several famous paradoxes. Aristotle responded to these paradoxes by developing the notion of a potential countable infinity, as well as the infinitely divisible continuum. Unlike the eternal and unchanging cycles of time, he believed the world is bounded by the celestial spheres and that cumulative stellar magnitude is only finitely multiplicative.

The Indian philosopher Kanada, founder of the Vaisheshika school, developed a notion of atomism and proposed that light and heat were varieties of the same substance.^[128] In the 5th century AD, the Buddhist atomist philosopher Dignāga proposed atoms to be point-sized, durationless, and made of energy. They denied the existence of substantial matter and proposed that movement consisted of momentary flashes of a stream of energy.^[129]

The notion of temporal finitism was inspired by the doctrine of creation shared by the three Abrahamic religions: Judaism, Christianity and Islam. The Christian philosopher, John Philoponus, presented the philosophical arguments against the ancient Greek notion of an infinite past and future. Philoponus' arguments against an infinite past were used by the early Muslim philosopher, Al-Kindi (Alkindus); the Jewish philosopher, Saadia Gaon (Saadia ben Joseph); and the Muslim theologian, Al-Ghazali (Algazel).

Astronomical concepts

Aristarchus's 3rd century BCE calculations on the relative sizes of from left the Sun, Earth and Moon, from a 10th-century AD Greek copy

Astronomical models of the Universe were proposed soon after astronomy began with the Babylonian astronomers, who viewed the Universe as a flat disk floating in the ocean, and this forms the premise for early Greek maps like those of Anaximander and Hecataeus of Miletus.

Later Greek philosophers, observing the motions of the heavenly bodies, were concerned with developing models of the Universe-based more profoundly on empirical evidence. The first coherent model was proposed by Eudoxus of Cnidos. According to Aristotle's physical interpretation of the model, celestial spheres eternally rotate with uniform motion around a stationary Earth. Normal matter is entirely contained within the terrestrial sphere.

De Mundo (composed before 250 BC or between 350 and 200 BC), stated, 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.^[130]

This model was also refined by Callippus and after concentric spheres were abandoned, it was brought into nearly perfect agreement with astronomical observations by Ptolemy. The success of such a model is largely due to the mathematical fact that any function (such as the position of a planet) can be decomposed into a set of circular functions (the Fourier modes). Other Greek scientists, such as the Pythagorean philosopher Philolaus, postulated (according to Stobaeus account) that at the center of the Universe was a "central fire" around which the Earth, Sun, Moon and Planets revolved in uniform circular motion.^[131]

The Greek astronomer Aristarchus of Samos was the first known individual to propose a heliocentric model of the Universe. Though the original text has been lost, a reference in Archimedes' book The Sand Reckoner describes Aristarchus's heliocentric model. Archimedes wrote: (translated into English):

"You, King Gelon, are aware the Universe is the name given by most astronomers to the sphere the center of which is the center of the Earth, while its radius is equal to the straight line between the center of the Sun and the center of the Earth. This is the common account as you have heard from astronomers. But Aristarchus has brought out a book consisting of certain hypotheses, wherein it appears, as a consequence of the assumptions made, that the Universe is many times greater than the Universe just mentioned. His hypotheses are that the fixed stars and the Sun remain unmoved, that the Earth revolves about the Sun on the circumference of a circle, the Sun lying in the middle of the orbit, and that the sphere of fixed stars, situated about the same center as the Sun, is so great that the circle in which he supposes the Earth to revolve bears such a proportion to the distance of the fixed stars as the center of the sphere bears to its surface"

Aristarchus thus believed the stars to be very far away, and saw this as the reason why stellar parallax had not been observed, that is, the stars had not been observed to move relative each other as the Earth moved around the Sun. The stars are in fact much farther away than the distance that was generally assumed in ancient times, which is why stellar parallax is only detectable with precision instruments. The geocentric model, consistent with planetary parallax, was assumed to be an explanation for the unobservability of the parallel phenomenon, stellar parallax. The rejection of the heliocentric view was apparently quite strong, as the following passage from Plutarch suggests (On the Apparent Face in the Orb of the Moon):

"Cleanthes [a contemporary of Aristarchus and head of the Stoics ] thought it was the duty of the Greeks to indict Aristarchus of Samos on the charge of impiety for putting in motion the Hearth of the Universe [i.e. the Earth], . . . supposing the heaven to remain at rest and the Earth to revolve in an oblique circle, while it rotates, at the same time, about its own axis"

Flammarion engraving, Paris 1888

The only other astronomer from antiquity known by name who supported Aristarchus's heliocentric model was Seleucus of Seleucia, a Hellenistic astronomer who lived a century after Aristarchus.^[132]^[133]^[134] According to Plutarch, Seleucus was the first to prove the heliocentric system through reasoning, but it is not known what arguments he used. Seleucus' arguments for a heliocentric cosmology were probably related to the phenomenon of tides.^[135] 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.^[136] Alternatively, he may have proved heliocentricity by determining the constants of a geometric model for it, and by developing methods to compute planetary positions using this model, like what Nicolaus Copernicus later did in the 16th century.^[137] During the Middle Ages, heliocentric models were also proposed by the Indian astronomer Aryabhata,^[138] and by the Persian astronomers Albumasar^[139] and Al-Sijzi.^[140]

Model of the Copernican Universe by Thomas Digges in 1576, with the amendment that the stars are no longer confined to a sphere, but spread uniformly throughout the space surrounding the planets.

The Aristotelian model was accepted in the Western world for roughly two millennia, until Copernicus revived Aristarchus's perspective that the astronomical data could be explained more plausibly if the earth rotated on its axis and if the sun were placed at the center of the Universe.

“

In the center rests the Sun. For who would place this lamp of a very beautiful temple in another or better place than this wherefrom it can illuminate everything at the same time?

”

—Nicolaus Copernicus, in Chapter 10, Book 1 of De Revolutionibus Orbium Coelestrum (1543)

As noted by Copernicus himself, the notion that the Earth rotates is very old, dating at least to Philolaus (c. 450 BC), Heraclides Ponticus (c. 350 BC) and Ecphantus the Pythagorean. Roughly a century before Copernicus, the Christian scholar Nicholas of Cusa also proposed that the Earth rotates on its axis in his book, On Learned Ignorance (1440).^[141] Aryabhata (476–550 AD/CE)^[142] and Al-Sijzi^[143] also proposed that the Earth rotates on its axis. Empirical evidence for the Earth's rotation on its axis, using the phenomenon of comets, was given by Tusi (1201–1274) and Ali Qushji (1403–1474).^[144]

This cosmology was accepted by Isaac Newton, Christiaan Huygens and later scientists.^[145] Edmund Halley (1720)^[146] and Jean-Philippe de Chéseaux (1744)^[147] noted independently that the assumption of an infinite space filled uniformly with stars would lead to the prediction that the nighttime sky would be as bright as the Sun itself; this became known as Olbers' paradox in the 19th century.^[148] Newton believed that an infinite space uniformly filled with matter would cause infinite forces and instabilities causing the matter to be crushed inwards under its own gravity.^[145] This instability was clarified in 1902 by the Jeans instability criterion.^[149] One solution to these paradoxes is the Charlier Universe, in which the matter is arranged hierarchically (systems of orbiting bodies that are themselves orbiting in a larger system, ad infinitum) in a fractal way such that the Universe has a negligibly small overall density; such a cosmological model had also been proposed earlier in 1761 by Johann Heinrich Lambert.^[56]^[150] A significant astronomical advance of the 18th century was the realization by Thomas Wright, Immanuel Kant and others of nebulae.^[146]

The modern era of physical cosmology began in 1917, when Albert Einstein first applied his general theory of relativity to model the structure and dynamics of the Universe.^[151]

References

^ ^a ^b ^c ^d Planck collaboration (2014). "Planck 2013 results. XVI. Cosmological parameters". Astronomy & Astrophysics. arXiv:1303.5076. Bibcode:2014A&A...571A..16P. doi:10.1051/0004-6361/201321591.
^ ^a ^b Itzhak Bars; John Terning (2009). Extra Dimensions in Space and Time. Springer. pp. 27ff. ISBN 978-0-387-77637-8. Retrieved 2011-05-01.
^ Paul Davies (2006). The Goldilocks Enigma. First Mariner Books. p. 43ff. ISBN 978-0-618-59226-5. Retrieved 2013-07-01.
^ ^a ^b NASA/WMAP Science Team (24 January 2014). "Universe 101: What is the Universe Made Of?". NASA. Retrieved 2015-02-17.
^ Fixsen, D. J. (2009). "The Temperature of the Cosmic Microwave Background". The Astrophysical Journal 707 (2): 916–920. arXiv:0911.1955. Bibcode:2009ApJ...707..916F. doi:10.1088/0004-637X/707/2/916.
^ ^a ^b ^c Sean Carroll, Ph.D., Cal Tech, 2007, The Teaching Company, Dark Matter, Dark Energy: The Dark Side of the Universe, Guidebook Part 1 pages 1 and 3, Accessed Oct. 7, 2013, "...only 5% of the Universe is made of ordinary matter, with 25 percent being some kind of unseen dark matter and a full 70% being a smoothly distributed dark energy..."
^ NASA/WMAP Science Team (24 January 2014). "Universe 101: Will the Universe expand forever?". NASA. Retrieved 16 April 2015.
^ Universe. Webster's New World College Dictionary, Wiley Publishing, Inc. 2010.
^ "Universe". Dictionary.com. Retrieved 2012-09-21.
^ "Universe". Merriam-Webster Dictionary. Retrieved 2012-09-21.
^ Zeilik, Michael; Gregory, Stephen A. (1998). Introductory Astronomy & Astrophysics (4th ed.). Saunders College Publishing. ISBN 0030062284. The totality of all space and time; all that is, has been, and will be.
^ ^a ^b Brian Greene (2011). The Hidden Reality. Alfred A. Knopf.
^ Dold-Samplonius, Yvonne (2002). From China to Paris: 2000 Years Transmission of Mathematical Ideas. Franz Steiner Verlag.
^ ^a ^b ^c Thomas F. Glick; Steven Livesey; Faith Wallis. Medieval Science Technology and Medicine: An Encyclopedia. Routledge.
^ Hawking, Stephen (1988). A Brief History of Time. Bantam Books. p. 125. ISBN 0-553-05340-X.
^ "The Nobel Prize in Physics 2011". Retrieved 16 April 2015.
^ ^a ^b The American Heritage Dictionary of the English Language (4th ed.). Houghton Mifflin Harcourt Publishing Company. 2010.
^ ^a ^b Cambridge Advanced Learner's Dictionary.
^ "Planck reveals an almost perfect universe". Planck. ESA. 2013-03-21. Retrieved 2013-03-21.
^ ^a ^b ^c ^d ^e ^f ^g Ellis, George F.R.; U. Kirchner; W.R. Stoeger (2004). "Multiverses and physical cosmology". Monthly Notices of the Royal Astronomical Society 347 (3): 921–936. arXiv:astro-ph/0305292. Bibcode:2004MNRAS.347..921E. doi:10.1111/j.1365-2966.2004.07261.x.
^ Palmer, Jason. (2011-08-03) BBC News – 'Multiverse' theory suggested by microwave background. Retrieved 2011-11-28.
^ Paul Copan; William Lane Craig (2004). Creation Out of Nothing: A Biblical, Philosophical, and Scientific Exploration. Baker Academic. p. 220. ISBN 9780801027338.
^ Alexander Bolonkin (November 2011). Universe, Human Immortality and Future Human Evaluation. Elsevier. pp. 3–. ISBN 978-0-12-415801-6.
^ Duco A. Schreuder (3 December 2014). Vision and Visual Perception. Archway Publishing. pp. 135–. ISBN 978-1-4808-1294-9.
^ Tegmark, Max. "The Mathematical Universe". Foundations of Physics 38 (2): 101–150. arXiv:0704.0646. Bibcode:2008FoPh...38..101T. doi:10.1007/s10701-007-9186-9. a short version of which is available at Shut up and calculate. (in reference to David Mermin's famous quote "shut up and calculate" [1]
^ Jim Holt (2012). Why Does the World Exist?. Liveright Publishing. p. 308.
^ Timothy Ferris (1997). The Whole Shebang: A State-of-the-Universe(s) Report. Simon & Schuster. p. 400.
^ The Compact Edition of the Oxford English Dictionary, volume II, Oxford: Oxford University Press, 1971, p. 3518.
^ ^a ^b Lewis, C. T. and Short, S (1879) A Latin Dictionary, Oxford University Press, ISBN 0-19-864201-6, pp. 1933, 1977–1978.
^ Liddell & Scott (1968, p. 1392)
^ Mary Louise Gill; Pierre Pellegrin (9 February 2009). A Companion to Ancient Philosophy. John Wiley & Sons. pp. 369–. ISBN 978-1-4051-7825-9.
^ Liddell & Scott (1968, pp. 1345–1346)
^ Yonge, Charles Duke (1870). An English-Greek lexicon. New York: American Book Company. p. 567.
^ Liddell & Scott (1968, pp. 985, 1964)
^ Lewis, C. T.; Short, S (1879). A Latin Dictionary. Oxford University Press. pp. 1881–1882, 1175, 1189–1190. ISBN 0-19-864201-6.
^ The Compact Edition of the Oxford English Dictionary II. Oxford: Oxford University Press. 1971. pp. 909, 569, 3821–3822, 1900. ISBN 978-0198611172.
^ Joseph Silk (2009). Horizons of Cosmology. Templeton Pressr. p. 208.
^ Simon Singh (2005). Big Bang: The Origin of the Universe. Harper Perennial. p. 560.
^ C. Sivaram (1986). "Evolution of the Universe through the Planck epoch". Astrophysics & Space Science 125: 189. Bibcode:1986Ap&SS.125..189S. doi:10.1007/BF00643984.
^ Richard B. Larson and Volker Bromm (March 2002). "The First Stars in the Universe". Scientific American.
^ Ryden, Barbara, "Introduction to Cosmology", 2006, eqn. 6.33
^ "Antimatter". Particle Physics and Astronomy Research Council. October 28, 2003. Retrieved 2006-08-10.
^ Landau and Lifshitz, p. 361.
^ Edward Robert Harrison (2000). Cosmology: the science of the universe. Cambridge University Press. pp. 447–. ISBN 978-0-521-66148-5. Retrieved 1 May 2011.
^ Andrew R. Liddle; David Hilary Lyth (13 April 2000). Cosmological inflation and large-scale structure. Cambridge University Press. pp. 24–. ISBN 978-0-521-57598-0. Retrieved 1 May 2011.
^ Will the Universe expand forever?, WMAP website at NASA.
^ ^a ^b Luminet, Jean-Pierre; Weeks, Jeffrey R.; Riazuelo, Alain; Lehoucq, Roland; Uzan, Jean-Philippe (2003-10-09). "Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background". Nature 425 (6958): 593–5. arXiv:astro-ph/0310253. Bibcode:2003Natur.425..593L. doi:10.1038/nature01944. PMID 14534579.
^ Roukema, Boudewijn; Zbigniew Buliński; Agnieszka Szaniewska; Nicolas E. Gaudin (2008). "A test of the Poincare dodecahedral space topology hypothesis with the WMAP CMB data". Astronomy and Astrophysics 482 (3): 747. arXiv:0801.0006. Bibcode:2008A&A...482..747L. doi:10.1051/0004-6361:20078777.
^ Aurich, Ralf; Lustig, S.; Steiner, F.; Then, H. (2004). "Hyperbolic Universes with a Horned Topology and the CMB Anisotropy". Classical and Quantum Gravity 21 (21): 4901–4926. arXiv:astro-ph/0403597. Bibcode:2004CQGra..21.4901A. doi:10.1088/0264-9381/21/21/010.
^ "Planck reveals 'almost perfect' universe". Michael Banks. Physics World. 2013-03-21. Retrieved 2013-03-21.
^ McCall, Storrs. A Model of the Universe: Space-time, Probability, and Decision. Oxford University. p. 23.
^ Michio Kaku (11 March 2008). Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel. Knopf Doubleday Publishing Group. pp. 202–. ISBN 978-0-385-52544-2.
^ "How can space travel faster than the speed of light?". Vannesa Janek. Universe Today. 20 February 2015. Retrieved 6 June 2015.
^ "Is faster-than-light travel or communication possible? Section: Expansion of the Universe". Philip Gibbs. 1997. Retrieved 6 June 2015.
^ Christopher Crockett (February 20, 2013). "What is a light-year?". EarthSky.
^ ^a ^b Rindler, p. 196.
^ Christian, Eric; Samar, Safi-Harb. "How large is the Milky Way?". Retrieved 2007-11-28.
^ I. Ribas; C. Jordi; F. Vilardell; E.L. Fitzpatrick; R.W. Hilditch; F. Edward Guinan (2005). "First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in the Andromeda Galaxy". Astrophysical Journal 635 (1): L37–L40. arXiv:astro-ph/0511045. Bibcode:2005ApJ...635L..37R. doi:10.1086/499161.
McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). "Distances and metallicities for 17 Local Group galaxies". Monthly Notices of the Royal Astronomical Society 356 (4): 979–997. arXiv:astro-ph/0410489. Bibcode:2005MNRAS.356..979M. doi:10.1111/j.1365-2966.2004.08514.x.
^ Phil Berardelli (March 25, 2010). "Galaxy Collisions Give Birth to Quasars". Science News.
^ Riess, Adam G.; Filippenko; Challis; Clocchiatti; Diercks; Garnavich; Gilliland; Hogan; Jha; Kirshner; Leibundgut; Phillips; Reiss; Schmidt; Schommer; Smith; Spyromilio; Stubbs; Suntzeff; Tonry (1998). "Observational evidence from supernovae for an accelerating universe and a cosmological constant". Astronomical J. 116 (3): 1009–38. arXiv:astro-ph/9805201. Bibcode:1998AJ....116.1009R. doi:10.1086/300499.
^ Perlmutter, S.; Aldering; Goldhaber; Knop; Nugent; Castro; Deustua; Fabbro; Goobar; Groom; Hook; Kim; Kim; Lee; Nunes; Pain; Pennypacker; Quimby; Lidman; Ellis; Irwin; McMahon; Ruiz‐Lapuente; Walton; Schaefer; Boyle; Filippenko; Matheson; Fruchter et al. (1999). "Measurements of Omega and Lambda from 42 high redshift supernovae". Astrophysical Journal 517 (2): 565–86. arXiv:astro-ph/9812133. Bibcode:1999ApJ...517..565P. doi:10.1086/307221.
^ Sean Carroll and Michio Kaku (2014). How the Universe Works 3. End of the Universe. Discovery Channel.
^ Overbye, Dennis (October 11, 2003). "A 'Cosmic Jerk' That Reversed the Universe". New York Times.
^ The Nobel Prize in Physics 2011
^ WMAP Mission: Results – Age of the Universe. Map.gsfc.nasa.gov. Retrieved 2011-11-28.
^ Luminet, Jean-Pierre; Boudewijn F. Roukema (1999). "Topology of the Universe: Theory and Observations". Proceedings of Cosmology School held at Cargese, Corsica, August 1998. arXiv:astro-ph/9901364.
^ Fritzsche, Hellmut. "electromagnetic radiation | physics". Encyclopedia Britannica. p. 1. Retrieved 2015-07-26.
^ "Physics 7:Relativity, SpaceTime and Cosmology" (PDF). Physics 7:Relativity, SpaceTime and Cosmology. University of California Riverside. Retrieved 2015-07-26.
^ "Physics - for the 21st Century". www.learner.org. Harvard-Smithsonian Center for Astrophysics Annenberg Learner. Retrieved 2015-07-27.
^ Redd,SPACE.com, Nola Taylor. "It's Official: The Universe Is Dying Slowly". Retrieved 2015-08-11.
^ RIP Universe - Your Time Is Coming… Slowly | Video, retrieved 2015-08-11
^ information@eso.org. "Charting the Slow Death of the Universe - GAMA survey releases first data at IAU General Assembly". www.eso.org. Retrieved 2015-08-11.
^ ^a ^b ^c Peebles, P. J. E. & Ratra, Bharat (2003). "The cosmological constant and dark energy". Reviews of Modern Physics 75 (2): 559–606. arXiv:astro-ph/0207347. Bibcode:2003RvMP...75..559P. doi:10.1103/RevModPhys.75.559.
^ "First Planck results: the Universe is still weird and interesting".
^ Mandolesi, N.; Calzolari, P.; Cortiglioni, S.; Delpino, F.; Sironi, G.; Inzani, P.; Deamici, G.; Solheim, J. -E.; Berger, L.; Partridge, R. B.; Martenis, P. L.; Sangree, C. H.; Harvey, R. C. (1986). "Large-scale homogeneity of the Universe measured by the microwave background". Nature 319 (6056): 751. doi:10.1038/319751a0. edit
^ Mackie, Glen (February 1, 2002). "To see the Universe in a Grain of Taranaki Sand". Swinburne University. Retrieved 2006-12-20.
^ "Unveiling the Secret of a Virgo Dwarf Galaxy". ESO. 2000-05-03. Retrieved 2007-01-03.
^ "Hubble's Largest Galaxy Portrait Offers a New High-Definition View". NASA. 2006-02-28. Retrieved 2007-01-03.
^ Vergano, Dan (1 December 2010). "Universe holds billions more stars than previously thought". USA Today. Retrieved 2010-12-14.
^ Earth's new address: 'Solar System, Milky Way, Laniakea' / Nature
^ http://www.universetoday.com/30286/local-group/
^ "Astronomers discover largest known structure in the universe is ... a big hole". The Guardian. 20 April 2015.
^ "WMAP 9 Year Mission Results". wmap.gsfc.nasa.gov. Retrieved 2015-07-26.
^ "WMAP- Content of the Universe". map.gsfc.nasa.gov. Retrieved 2015-07-26.
^ "Content of the Universe - WMAP 9yr Pie Chart". wmap.gsfc.nasa.gov. Retrieved 2015-07-26.
^ Hinshaw, Gary (November 29, 2006). "New Three Year Results on the Oldest Light in the Universe". NASA WMAP. Retrieved 2006-08-10.
^ Hinshaw, Gary (December 15, 2005). "Tests of the Big Bang: The CMB". NASA WMAP. Retrieved 2007-01-09.
^ Rindler, p. 202.
^ "Dark Energy". Hyperphysics. Retrieved January 4, 2014. ^{[unreliable source?]}
^ Carroll, Sean (2001). "The cosmological constant". Living Reviews in Relativity 4. Retrieved 2006-09-28.
^ "Planck captures portrait of the young Universe, revealing earliest light". University of Cambridge. 21 March 2013. Retrieved 21 March 2013.
^ P. Davies (1992). The New Physics: A Synthesis. Cambridge University Press. p. 1. ISBN 0-521-43831-4.
^ G. 't Hooft (1997). In search of the ultimate building blocks. Cambridge University Press. p. 6. ISBN 0-521-57883-3.
^ "RHIC Scientists Serve Up "Perfect" Liquid" (Press release). Brookhaven National Laboratory. 18 April 2005. Retrieved 2009-09-15.
^ ^a ^b Sylvie Braibant; Giorgio Giacomelli; Maurizio Spurio (2012). Particles and Fundamental Interactions: An Introduction to Particle Physics (2nd ed.). Springer. pp. 1–3. ISBN 978-94-007-2463-1.
^ Strobel, Nick (May 23, 2001). "The Composition of Stars". Astronomy Notes. Retrieved 2007-01-04.
"Have physical constants changed with time?". Astrophysics (Astronomy Frequently Asked Questions). Retrieved 2007-01-04.
^ R. Oerter (2006). The Theory of Almost Everything: The Standard Model, the Unsung Triumph of Modern Physics (Kindle ed.). Penguin Group. p. 2. ISBN 0-13-236678-9.
^ "Lepton (physics)". Encyclopædia Britannica. Retrieved 2010-09-29.
^ Harari, H. (1977). "Beyond charm". In Balian, R.; Llewellyn-Smith, C.H. Weak and Electromagnetic Interactions at High Energy, Les Houches, France, Jul 5- Aug 14, 1976. Les Houches Summer School Proceedings 29. North-Holland. p. 613.
^ Harari H. (1977). "Three generations of quarks and leptons" (PDF). In E. van Goeler, Weinstein R. (eds.). Proceedings of the XII Rencontre de Moriond. p. 170. SLAC-PUB-1974.
^ "Experiment confirms famous physics model" (Press release). MIT News Office. 18 April 2007.
^ The Timescale of Creation
^ Veltman, Martinus (2003). Facts and Mysteries in Elementary Particle Physics. World Scientific. ISBN 981-238-149-X.
^ Onyisi, P. (23 October 2012). "Higgs boson FAQ". University of Texas ATLAS group. Retrieved 2013-01-08.
^ ^a ^b Strassler, M. (12 October 2012). "The Higgs FAQ 2.0". ProfMattStrassler.com. Retrieved 2013-01-08. [Q] Why do particle physicists care so much about the Higgs particle?
[A] Well, actually, they don’t. What they really care about is the Higgs field, because it is so important. [emphasis in original]
^ Ray d'Inverno (1992), Introducing Einstein's Relativity, Clarendon Press, chp. 22.8 Geometry of 3-spaces of constant curvature, p.319ff, ISBN 0-19-859653-7
^ Albert Einstein (1905) "Zur Elektrodynamik bewegter Körper", Annalen der Physik 17: 891; English translation On the Electrodynamics of Moving Bodies by George Barker Jeffery and Wilfrid Perrett (1923); Another English translation On the Electrodynamics of Moving Bodies by Megh Nad Saha (1920).
^ Tom Roberts and Siegmar Schleif (October 2007). "What is the experimental basis of Special Relativity?". Usenet Physics FAQ. Retrieved 2008-09-17.
^ Albert Einstein (2001). Relativity: The Special and the General Theory (Reprint of 1920 translation by Robert W. Lawson ed.). Routledge. p. 48. ISBN 0-415-25384-5.
^ Richard Phillips Feynman (1998). Six Not-so-easy Pieces: Einstein's relativity, symmetry, and space–time (Reprint of 1995 ed.). Basic Books. p. 68. ISBN 0-201-32842-9.
^ O'Connor, J.J. and E.F. Robertson (1996), "General relativity". Mathematical Physics index, School of Mathematics and Statistics, University of St. Andrews, Scotland, May, 1996. Retrieved 2015-02-04.
^ ^a ^b ^c ^d Zeilik, Michael; Gregory, Stephen A. (1998). "25-2". Introductory Astronomy & Astrophysics (4th ed.). Saunders College Publishing. ISBN 0030062284.
^ Friedmann A. (1922). "Über die Krümmung des Raumes" (PDF). Zeitschrift für Physik 10 (1): 377–386. Bibcode:1922ZPhy...10..377F. doi:10.1007/BF01332580.
^ "Cosmic Detectives". The European Space Agency (ESA). 2013-04-02. Retrieved 2013-04-15.
^ Munitz MK (1959). "One Universe or Many?". Journal of the History of Ideas 12 (2): 231–255. doi:10.2307/2707516. JSTOR 2707516.
^ Linde A. (1986). "Eternal chaotic inflation". Mod. Phys. Lett. A1 (2): 81–85. Bibcode:1986MPLA....1...81L. doi:10.1142/S0217732386000129.
Linde A. (1986). "Eternally existing self-reproducing chaotic inflationary Universe" (PDF). Phys. Lett. B175 (4): 395–400. Bibcode:1986PhLB..175..395L. doi:10.1016/0370-2693(86)90611-8. Retrieved 2011-03-17.
^ ^a ^b Tegmark M. (2003). "Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations". Scientific American 288 (5): 40–51. doi:10.1038/scientificamerican0503-40. PMID 12701329.
^ Tegmark, Max (2003). J. D. Barrow; P.C.W. Davies; C.L. Harper, eds. "Parallel Universes". Scientific American: "Science and Ultimate Reality: from Quantum to Cosmos", honoring John Wheeler's 90th birthday (Cambridge University Press): 2131. arXiv:astro-ph/0302131. Bibcode:2003astro.ph..2131T. doi:10.1038/scientificamerican0503-40.
^ Ellis G. F (2011). "Does the Multiverse Really Exist?". Scientific American 305 (2): 38–43. doi:10.1038/scientificamerican0811-38.
^ Clara Moskowitz (August 12, 2011). "Weird! Our Universe May Be a 'Multiverse,' Scientists Say". livescience.
^ Mark Isaak (ed.) (2005). "CI301: The Anthropic Principle". Index to Creationist Claims. TalkOrigins Archive. Retrieved 2007-10-31.
^ Gernet, J. (1993–1994). "Space and time: Science and religion in the encounter between China and Europe". Chinese Science 11. pp. 93–102.
^ Ng, Tai (2007). "III.3". Chinese Culture, Western Culture: Why Must We Learn from Each Other?. iUniverse, Inc.
^ Blandford R. D. "A century of general relativity: Astrophysics and cosmology". Science 347 (6226): 103–108. Bibcode:2015Sci...347.1103B. doi:10.1126/science.aaa4033.
^ Leeming, David A. (2010). Creation Myths of the World. ABC-CLIO. p. xvii. ISBN 978-1-59884-174-9. In common usage the word 'myth' refers to narratives or beliefs that are untrue or merely fanciful; the stories that make up national or ethnic mythologies describe characters and events that common sense and experience tell us are impossible. Nevertheless, all cultures celebrate such myths and attribute to them various degrees of literal or symbolic truth.
^ (Henry Gravrand, "La civilisation Sereer -Pangool") [in] Universität Frankfurt am Main, Frobenius-Institut, Deutsche Gesellschaft für Kulturmorphologie, Frobenius Gesellschaft, "Paideuma: Mitteilungen zur Kulturkunde, Volumes 43–44", F. Steiner (1997), pp. 144–5, ISBN 3515028420
^ B. Young, Louise. The Unfinished Universe. Oxford University Press. p. 21.
^ Will Durant, Our Oriental Heritage:

"Two systems of Hindu thought propound physical theories suggestively similar to those of Greece. Kanada, founder of the Vaisheshika philosophy, held that the world is composed of atoms as many in kind as the various elements. The Jains more nearly approximated to Democritus by teaching that all atoms were of the same kind, producing different effects by diverse modes of combinations. Kanada believed light and heat to be varieties of the same substance; Udayana taught that all heat comes from the Sun; and Vachaspati, like Newton, interpreted light as composed of minute particles emitted by substances and striking the eye."
^ Stcherbatsky, F. Th. (1930, 1962), Buddhist Logic, Volume 1, p. 19, Dover, New York:

"The Buddhists denied the existence of substantial matter altogether. Movement consists for them of moments, it is a staccato movement, momentary flashes of a stream of energy... "Everything is evanescent",... says the Buddhist, because there is no stuff... Both systems [Sānkhya, and later Indian Buddhism] share in common a tendency to push the analysis of existence up to its minutest, last elements which are imagined as absolute qualities, or things possessing only one unique quality. They are called "qualities" (guna-dharma) in both systems in the sense of absolute qualities, a kind of atomic, or intra-atomic, energies of which the empirical things are composed. Both systems, therefore, agree in denying the objective reality of the categories of Substance and Quality,... and of the relation of Inference uniting them. There is in Sānkhya philosophy no separate existence of qualities. What we call quality is but a particular manifestation of a subtle entity. To every new unit of quality corresponds a subtle quantum of matter which is called guna, "quality", but represents a subtle substantive entity. The same applies to early Buddhism where all qualities are substantive... or, more precisely, dynamic entities, although they are also called dharmas ('qualities')."
^ Aristotle; Forster, E. S. (Edward Seymour), 1879-1950; Dobson, J. F. (John Frederic), 1875-1947 (1914). De Mundo. p. 2.
^ Boyer, C. (1968) A History of Mathematics. Wiley, p. 54.
^ Neugebauer, Otto E. (1945). "The History of Ancient Astronomy Problems and Methods". Journal of Near Eastern Studies 4 (1): 1–38. doi:10.1086/370729. JSTOR 595168. the Chaldaean Seleucus from Seleucia
^ Sarton, George (1955). "Chaldaean Astronomy of the Last Three Centuries B. C". Journal of the American Oriental Society 75 (3): 166–173 (169). doi:10.2307/595168. JSTOR 595168. the heliocentrical astronomy invented by Aristarchos of Samos and still defended a century later by Seleucos the Babylonian
^ William P. D. Wightman (1951, 1953), The Growth of Scientific Ideas, Yale University Press p. 38, where Wightman calls him Seleukos the Chaldean.
^ Lucio Russo, Flussi e riflussi, Feltrinelli, Milano, 2003, ISBN 88-07-10349-4.
^ Bartel (1987, p. 527)
^ Bartel (1987, pp. 527–9)
^ Bartel (1987, pp. 529–34)
^ Bartel (1987, pp. 534–7)
^ Nasr, Seyyed H. (1993) [1964]. An Introduction to Islamic Cosmological Doctrines (2nd ed.). 1st edition by Harvard University Press, 2nd edition by State University of New York Press. pp. 135–6. ISBN 0-7914-1515-5.
^ Misner, Thorne and Wheeler, p. 754.
^ Abhishek Parakh (2006). "A Note on Aryabhata's Principle of Relativity". arXiv:physics/0610095.
^ Ālī, Ema Ākabara. Science in the Quran 1. Malik Library. p. 218.
^ Ragep, F. Jamil (2001), "Tusi and Copernicus: The Earth's Motion in Context", Science in Context (Cambridge University Press) 14 (1–2): 145–163, doi:10.1017/s0269889701000060
^ ^a ^b Misner, Thorne and Wheeler, p. 755–756.
^ ^a ^b Misner, Thorne and Wheeler, p. 756.
^ de Cheseaux JPL (1744). Traité de la Comète. Lausanne. pp. 223ff. . Reprinted as Appendix II in Dickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press. ISBN 978-0-262-54003-2.
^ Olbers HWM (1826). "Unknown title". Bode's Jahrbuch 111. . Reprinted as Appendix I in Dickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press. ISBN 978-0-262-54003-2.
^ Jeans, J. H. (1902). "The Stability of a Spherical Nebula" (PDF). Philosophical Transactions of the Royal Society A 199 (312–320): 1–53. Bibcode:1902RSPTA.199....1J. doi:10.1098/rsta.1902.0012. JSTOR 90845. Retrieved 2011-03-17.
^ Misner, Thorne and Wheeler, p. 757.
^ Einstein, A (1917). "Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie". Preussische Akademie der Wissenschaften, Sitzungsberichte. 1917. (part 1): 142–152.

Sources

Bartel, Leendert van der Waerden (1987). "The Heliocentric System in Greek, Persian and Hindu Astronomy". Annals of the New York Academy of Sciences 500 (1): 525–545. Bibcode:1987NYASA.500..525V. doi:10.1111/j.1749-6632.1987.tb37224.x.
Landau, Lev, Lifshitz, E.M. (1975). The Classical Theory of Fields (Course of Theoretical Physics) 2 (revised 4th English ed.). New York: Pergamon Press. pp. 358–397. ISBN 978-0-08-018176-9.
Liddell, H. G. & Scott, R. (1968). A Greek-English Lexicon. Oxford University Press. ISBN 0-19-864214-8.
Misner, C.W., Thorne, Kip, Wheeler, J.A. (1973). Gravitation. San Francisco: W. H. Freeman. pp. 703–816. ISBN 978-0-7167-0344-0.
Rindler, W. (1977). Essential Relativity: Special, General, and Cosmological. New York: Springer Verlag. pp. 193–244. ISBN 0-387-10090-3.

UpToDate Contents

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1. 混合性結合組織病における抗U1-RNP抗体 anti u1 rnp antibodies in mixed connective tissue disease
2. 心筋活動電位および抗不整脈剤の作用 myocardial action potential and action of antiarrhythmic drugs
3. 刺鍼法 acupuncture
4. シャーガス心臓病の臨床症状および診断 clinical manifestations and diagnosis of chagas heart disease
5. 病院前小児科医療および救急医療（EMS） prehospital pediatrics and emergency medical services ems

English Journal

Musculoskeletal pain among healthcare workers: An exploratory study on gender differences.

Barbosa RE, Assunção AÁ, de Araújo TM.SourceFederal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
American journal of industrial medicine.Am J Ind Med.2013 Oct;56(10):1201-12. doi: 10.1002/ajim.22215. Epub 2013 Jul 19.
BACKGROUND: Musculoskeletal disorder rates among healthcare workers are high compared to other occupational groups. Studies indicate a higher prevalence of musculoskeletal pain in women as compared to men in most productive sectors. The objectives of our study were to assess the prevalence of upper-
PMID 23868813

Emerging paradigms in arterial thrombosis.

Wisler JW, Becker RC.SourceDivision of Cardiology, Duke University Medical Center, 7400, 2301 Erwin Rd., Durham, NC, 27705, USA, jim.wisler@duke.edu.
Journal of thrombosis and thrombolysis.J Thromb Thrombolysis.2013 Sep 18. [Epub ahead of print]
A traditional perspective of arterial thrombosis begins with vessel wall injury and exposure of subendothelial proteins, including collagen and tissue factor, to circulating cellular and non-cellular components. Adhesion and activation of platelets, mediated by their interaction with von Willebrand
PMID 24046067

The multiuniverse transition in superfluid 3He.

Bunkov Y.SourceInstitut NEEL, CNRS, 25, Avenue des Martyrs, Grenoble, France.
Journal of physics. Condensed matter : an Institute of Physics journal.J Phys Condens Matter.2013 Sep 11;25(40):404205. [Epub ahead of print]
The symmetry-breaking phase transitions of the universe and of superfluid 3He may lead to the formation of different states with different order parameters. In both cases the energy potential below the transition temperature has a complicated multidimensional profile with many local minima and saddl
PMID 24026020

Annihilation dynamics of stringlike topological defects in a nematic lyotropic liquid crystal.

Guimarães RR, Mendes RS, Fernandes PR, Mukai H.SourceDepartamento de Física, Universidade Estadual de Maringá, Avenida Colombo - 5790, 87020-900, Maringá, PR, Brazil.
Journal of physics. Condensed matter : an Institute of Physics journal.J Phys Condens Matter.2013 Sep 11;25(40):404203. [Epub ahead of print]
Topological defects can appear whenever there is some type of ordering. Its ubiquity in nature has been the subject of several studies, from early Universe to condensed matter. In this work, we investigated the annihilation dynamics of defects and antidefects in a lyotropic nematic liquid crystal (t
PMID 24025970

Japanese Journal

QUANTUM CANONICAL TENSOR MODEL AND AN EXACT WAVE FUNCTION

SASAKURA NAOKI
International Journal of Modern Physics A 28(21), 2013-08-20
… Thus one could consistently obtain, at least locally in the configuration space, wave functions of "universe" by solving the partial differential equations representing the constraints, i.e. the Wheeler–DeWitt equations for the quantum canonical tensor model. … it shows that locality is favored, and that there exists a locus of configurations with features of beginning of universe. …
NAID 120005324897

Phenomenology of S4 flavor symmetric extra U(1) model

Daikoku Yasuhiro,Okada Hiroshi
Physical Review D - Particles, Fields, Gravitation and Cosmology 83(1), 015034, 2013-07-31
… As the extra Higgs bosons are neutrinophilic, baryon number asymmetry in the Universe is realized by leptogenesis without causing gravitino overproduction. …
NAID 120005327235

あわらキャンパス10mパラボラアンテナシステムの宇宙への新しい窓を拓く衛星地上局としての現状と将来展望

中城智之,Nakajo Tomoyuki,青山隆司,Aoyama Takashi,加藤芳信,Kato Yoshinobu
福井工業大学研究紀要 43, 58-65, 2013-07-14
… For a long time, the universe has been yearning that is not accessible directly for general public.However, progress of nano-satellite technologies in the past 10 years is changing the situation and going to open a new window to universe. … In the article, we mention the current status of data reception project and future perspective which will open the new window to universe for us. …
NAID 120005298783

Thermodynamics with Interacting Dark Energy in Magnetic Universe

Sharif Muhammad,Saleem Rabia
J Phys Soc Jpn 82(6), 064006-064006-7, 2013-06-15
… In this paper, we investigate the validity of generalized second law of thermodynamics for FRW universe in the framework of non-linear electrodynamics. … We assume that the universe is composed of dark matter, magnetic field and some unknown dark energy component with two different interacting terms Q and \tilde{Q}. …
NAID 150000107656

Related Pictures

★リンクテーブル★

リンク元	「area」「space」「region」「regional」「realm」

「area」

The Universe
	WMAP image of cosmic background radiation
Age	13.798 ± 0.037 billion years
Diameter	Possibly infinite; at least 91 billion light-years (28×109 pc)
Mass (ordinary matter)	At least 1053 kg
Average density	4.5 x 10−31 g/cm3
Average temperature	2.72548 K
Main Contents	Ordinary (baryonic) matter (4.9%), dark matter (26.8%), dark energy (68.3%)
Shape	Flat with only a 0.4% margin of error

　　[★]

n.

面積、範囲、分野、区域、領域、部域、地域

関: district、domain、extent、field、local、range、reach、realm、region、regional、scope、segment、segmental、spectra、spectrum、territory、universe

「space」

　　[★] n.

スペース、

vt.

(事)を一定間隔で行う

ex. oral doses should be spaced wqually to maintein a continuous high concentraction of iron in plasma.

関: alveus、cavity、cosmic、room、universe、ventriculi、ventriculus

「region」

　　[★]

n.

領域、区域、部分、地域

関: area、district、division、domain、local、moiety、part、partial、piece、portion、realm、regional、segment、segmental、territory、universe

「regional」

　　[★]

領域の、領域性の、局所の

関: area、domain、local、locoregional、realm、region、regionally、spot、territory、universe

「realm」

　　[★]

n.

領域、範囲

関: area、domain、extent、range、reach、region、regional、scope、spectra、spectrum、territory、universe

[planck_cosmological_parameters-1] Planck collaboration (2014). "Planck 2013 results. XVI. Cosmological parameters". Astronomy & Astrophysics. arXiv:1303.5076. Bibcode:2014A&A...571A..16P. doi:10.1051/0004-6361/201321591.

[Extra-Dimensions-2] Itzhak Bars; John Terning (2009). Extra Dimensions in Space and Time. Springer. pp. 27ff. ISBN 978-0-387-77637-8. Retrieved 2011-05-01.

[Paul_Davies_2006_43-3] Paul Davies (2006). The Goldilocks Enigma. First Mariner Books. p. 43ff. ISBN 978-0-618-59226-5. Retrieved 2013-07-01.

[wmap_universe_made_of-4] NASA/WMAP Science Team (24 January 2014). "Universe 101: What is the Universe Made Of?". NASA. Retrieved 2015-02-17.

[5] Fixsen, D. J. (2009). "The Temperature of the Cosmic Microwave Background". The Astrophysical Journal 707 (2): 916–920. arXiv:0911.1955. Bibcode:2009ApJ...707..916F. doi:10.1088/0004-637X/707/2/916.

[DarkMatter-6] Sean Carroll, Ph.D., Cal Tech, 2007, The Teaching Company, Dark Matter, Dark Energy: The Dark Side of the Universe, Guidebook Part 1 pages 1 and 3, Accessed Oct. 7, 2013, "...only 5% of the Universe is made of ordinary matter, with 25 percent being some kind of unseen dark matter and a full 70% being a smoothly distributed dark energy..."

[7] NASA/WMAP Science Team (24 January 2014). "Universe 101: Will the Universe expand forever?". NASA. Retrieved 16 April 2015.

[8] Universe. Webster's New World College Dictionary, Wiley Publishing, Inc. 2010.

[9] "Universe". Dictionary.com. Retrieved 2012-09-21.

[10] "Universe". Merriam-Webster Dictionary. Retrieved 2012-09-21.

[11] Zeilik, Michael; Gregory, Stephen A. (1998). Introductory Astronomy & Astrophysics (4th ed.). Saunders College Publishing. ISBN 0030062284. The totality of all space and time; all that is, has been, and will be.

[Brian_Greene_2011-12] Brian Greene (2011). The Hidden Reality. Alfred A. Knopf.

[13] Dold-Samplonius, Yvonne (2002). From China to Paris: 2000 Years Transmission of Mathematical Ideas. Franz Steiner Verlag.

[Routledge-14] Thomas F. Glick; Steven Livesey; Faith Wallis. Medieval Science Technology and Medicine: An Encyclopedia. Routledge.

[Hawking-15] Hawking, Stephen (1988). A Brief History of Time. Bantam Books. p. 125. ISBN 0-553-05340-X.

[16] "The Nobel Prize in Physics 2011". Retrieved 16 April 2015.

[AHD-17] The American Heritage Dictionary of the English Language (4th ed.). Houghton Mifflin Harcourt Publishing Company. 2010.

[CALD-18] Cambridge Advanced Learner's Dictionary.

[Planck_perfectuniverse-19] "Planck reveals an almost perfect universe". Planck. ESA. 2013-03-21. Retrieved 2013-03-21.

[EllisKS032-20] ^ ^a ^b ^c ^d ^e ^f ^g Ellis, George F.R.; U. Kirchner; W.R. Stoeger (2004). "Multiverses and physical cosmology". Monthly Notices of the Royal Astronomical Society 347 (3): 921–936. arXiv:astro-ph/0305292. Bibcode:2004MNRAS.347..921E. doi:10.1111/j.1365-2966.2004.07261.x.

[21] Palmer, Jason. (2011-08-03) BBC News – 'Multiverse' theory suggested by microwave background. Retrieved 2011-11-28.

[22] Paul Copan; William Lane Craig (2004). Creation Out of Nothing: A Biblical, Philosophical, and Scientific Exploration. Baker Academic. p. 220. ISBN 9780801027338.

[Bolonkin2011-23] Alexander Bolonkin (November 2011). Universe, Human Immortality and Future Human Evaluation. Elsevier. pp. 3–. ISBN 978-0-12-415801-6.

[Schreuder2014-24] Duco A. Schreuder (3 December 2014). Vision and Visual Perception. Archway Publishing. pp. 135–. ISBN 978-1-4808-1294-9.

[25] Tegmark, Max. "The Mathematical Universe". Foundations of Physics 38 (2): 101–150. arXiv:0704.0646. Bibcode:2008FoPh...38..101T. doi:10.1007/s10701-007-9186-9. a short version of which is available at Shut up and calculate. (in reference to David Mermin's famous quote "shut up and calculate" [1]

[26] Jim Holt (2012). Why Does the World Exist?. Liveright Publishing. p. 308.

[27] Timothy Ferris (1997). The Whole Shebang: A State-of-the-Universe(s) Report. Simon & Schuster. p. 400.

[28] The Compact Edition of the Oxford English Dictionary, volume II, Oxford: Oxford University Press, 1971, p. 3518.

[lewis_short-29] Lewis, C. T. and Short, S (1879) A Latin Dictionary, Oxford University Press, ISBN 0-19-864201-6, pp. 1933, 1977–1978.

[30] Liddell & Scott (1968, p. 1392)

[GillPellegrin2009-31] Mary Louise Gill; Pierre Pellegrin (9 February 2009). A Companion to Ancient Philosophy. John Wiley & Sons. pp. 369–. ISBN 978-1-4051-7825-9.

[32] Liddell & Scott (1968, pp. 1345–1346)

[33] Yonge, Charles Duke (1870). An English-Greek lexicon. New York: American Book Company. p. 567.

[34] Liddell & Scott (1968, pp. 985, 1964)

[35] Lewis, C. T.; Short, S (1879). A Latin Dictionary. Oxford University Press. pp. 1881–1882, 1175, 1189–1190. ISBN 0-19-864201-6.

[36] The Compact Edition of the Oxford English Dictionary II. Oxford: Oxford University Press. 1971. pp. 909, 569, 3821–3822, 1900. ISBN 978-0198611172.

[37] Joseph Silk (2009). Horizons of Cosmology. Templeton Pressr. p. 208.

[38] Simon Singh (2005). Big Bang: The Origin of the Universe. Harper Perennial. p. 560.

[Sivaram-39] C. Sivaram (1986). "Evolution of the Universe through the Planck epoch". Astrophysics & Space Science 125: 189. Bibcode:1986Ap&SS.125..189S. doi:10.1007/BF00643984.

[40] Richard B. Larson and Volker Bromm (March 2002). "The First Stars in the Universe". Scientific American.

[41] Ryden, Barbara, "Introduction to Cosmology", 2006, eqn. 6.33

[42] "Antimatter". Particle Physics and Astronomy Research Council. October 28, 2003. Retrieved 2006-08-10.

[43] Landau and Lifshitz, p. 361.

[books.google.com-44] Edward Robert Harrison (2000). Cosmology: the science of the universe. Cambridge University Press. pp. 447–. ISBN 978-0-521-66148-5. Retrieved 1 May 2011.

[45] Andrew R. Liddle; David Hilary Lyth (13 April 2000). Cosmological inflation and large-scale structure. Cambridge University Press. pp. 24–. ISBN 978-0-521-57598-0. Retrieved 1 May 2011.

[nasa_popular_uni_curv-46] Will the Universe expand forever?, WMAP website at NASA.

[Nat03-47] Luminet, Jean-Pierre; Weeks, Jeffrey R.; Riazuelo, Alain; Lehoucq, Roland; Uzan, Jean-Philippe (2003-10-09). "Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background". Nature 425 (6958): 593–5. arXiv:astro-ph/0310253. Bibcode:2003Natur.425..593L. doi:10.1038/nature01944. PMID 14534579.

[RBSG08-48] Roukema, Boudewijn; Zbigniew Buliński; Agnieszka Szaniewska; Nicolas E. Gaudin (2008). "A test of the Poincare dodecahedral space topology hypothesis with the WMAP CMB data". Astronomy and Astrophysics 482 (3): 747. arXiv:0801.0006. Bibcode:2008A&A...482..747L. doi:10.1051/0004-6361:20078777.

[Aurich0403597-49] Aurich, Ralf; Lustig, S.; Steiner, F.; Then, H. (2004). "Hyperbolic Universes with a Horned Topology and the CMB Anisotropy". Classical and Quantum Gravity 21 (21): 4901–4926. arXiv:astro-ph/0403597. Bibcode:2004CQGra..21.4901A. doi:10.1088/0264-9381/21/21/010.

[50] "Planck reveals 'almost perfect' universe". Michael Banks. Physics World. 2013-03-21. Retrieved 2013-03-21.

[51] McCall, Storrs. A Model of the Universe: Space-time, Probability, and Decision. Oxford University. p. 23.

[Kaku2008-52] Michio Kaku (11 March 2008). Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel. Knopf Doubleday Publishing Group. pp. 202–. ISBN 978-0-385-52544-2.

[53] "How can space travel faster than the speed of light?". Vannesa Janek. Universe Today. 20 February 2015. Retrieved 6 June 2015.

[54] "Is faster-than-light travel or communication possible? Section: Expansion of the Universe". Philip Gibbs. 1997. Retrieved 6 June 2015.

[55] Christopher Crockett (February 20, 2013). "What is a light-year?". EarthSky.

[r196-56] Rindler, p. 196.

[57] Christian, Eric; Samar, Safi-Harb. "How large is the Milky Way?". Retrieved 2007-11-28.

[58] I. Ribas; C. Jordi; F. Vilardell; E.L. Fitzpatrick; R.W. Hilditch; F. Edward Guinan (2005). "First Determination of the Distance and Fundamental Properties of an Eclipsing Binary in the Andromeda Galaxy". Astrophysical Journal 635 (1): L37–L40. arXiv:astro-ph/0511045. Bibcode:2005ApJ...635L..37R. doi:10.1086/499161.
McConnachie, A. W.; Irwin, M. J.; Ferguson, A. M. N.; Ibata, R. A.; Lewis, G. F.; Tanvir, N. (2005). "Distances and metallicities for 17 Local Group galaxies". Monthly Notices of the Royal Astronomical Society 356 (4): 979–997. arXiv:astro-ph/0410489. Bibcode:2005MNRAS.356..979M. doi:10.1111/j.1365-2966.2004.08514.x.

[59] Phil Berardelli (March 25, 2010). "Galaxy Collisions Give Birth to Quasars". Science News.

[riess-60] Riess, Adam G.; Filippenko; Challis; Clocchiatti; Diercks; Garnavich; Gilliland; Hogan; Jha; Kirshner; Leibundgut; Phillips; Reiss; Schmidt; Schommer; Smith; Spyromilio; Stubbs; Suntzeff; Tonry (1998). "Observational evidence from supernovae for an accelerating universe and a cosmological constant". Astronomical J. 116 (3): 1009–38. arXiv:astro-ph/9805201. Bibcode:1998AJ....116.1009R. doi:10.1086/300499.

[perlmutter-61] Perlmutter, S.; Aldering; Goldhaber; Knop; Nugent; Castro; Deustua; Fabbro; Goobar; Groom; Hook; Kim; Kim; Lee; Nunes; Pain; Pennypacker; Quimby; Lidman; Ellis; Irwin; McMahon; Ruiz‐Lapuente; Walton; Schaefer; Boyle; Filippenko; Matheson; Fruchter et al. (1999). "Measurements of Omega and Lambda from 42 high redshift supernovae". Astrophysical Journal 517 (2): 565–86. arXiv:astro-ph/9812133. Bibcode:1999ApJ...517..565P. doi:10.1086/307221.

[62] Sean Carroll and Michio Kaku (2014). How the Universe Works 3. End of the Universe. Discovery Channel.

[63] Overbye, Dennis (October 11, 2003). "A 'Cosmic Jerk' That Reversed the Universe". New York Times.

[64] The Nobel Prize in Physics 2011

[Shape-65] WMAP Mission: Results – Age of the Universe. Map.gsfc.nasa.gov. Retrieved 2011-11-28.

[_spacetime_topology-66] Luminet, Jean-Pierre; Boudewijn F. Roukema (1999). "Topology of the Universe: Theory and Observations". Proceedings of Cosmology School held at Cargese, Corsica, August 1998. arXiv:astro-ph/9901364.

[67] Fritzsche, Hellmut. "electromagnetic radiation | physics". Encyclopedia Britannica. p. 1. Retrieved 2015-07-26.

[68] "Physics 7:Relativity, SpaceTime and Cosmology" (PDF). Physics 7:Relativity, SpaceTime and Cosmology. University of California Riverside. Retrieved 2015-07-26.

[69] "Physics - for the 21st Century". www.learner.org. Harvard-Smithsonian Center for Astrophysics Annenberg Learner. Retrieved 2015-07-27.

[70] Redd,SPACE.com, Nola Taylor. "It's Official: The Universe Is Dying Slowly". Retrieved 2015-08-11.

[71] RIP Universe - Your Time Is Coming… Slowly | Video, retrieved 2015-08-11

[72] rmation@eso.org. "Charting the Slow Death of the Universe - GAMA survey releases first data at IAU General Assembly". www.eso.org. Retrieved 2015-08-11.

[peebles-73] Peebles, P. J. E. & Ratra, Bharat (2003). "The cosmological constant and dark energy". Reviews of Modern Physics 75 (2): 559–606. arXiv:astro-ph/0207347. Bibcode:2003RvMP...75..559P. doi:10.1103/RevModPhys.75.559.

[wmap7parameters-74] "First Planck results: the Universe is still weird and interesting".

[75] Mandolesi, N.; Calzolari, P.; Cortiglioni, S.; Delpino, F.; Sironi, G.; Inzani, P.; Deamici, G.; Solheim, J. -E.; Berger, L.; Partridge, R. B.; Martenis, P. L.; Sangree, C. H.; Harvey, R. C. (1986). "Large-scale homogeneity of the Universe measured by the microwave background". Nature 319 (6056): 751. doi:10.1038/319751a0. edit

[76] Mackie, Glen (February 1, 2002). "To see the Universe in a Grain of Taranaki Sand". Swinburne University. Retrieved 2006-12-20.

[77] "Unveiling the Secret of a Virgo Dwarf Galaxy". ESO. 2000-05-03. Retrieved 2007-01-03.

[M101-78] "Hubble's Largest Galaxy Portrait Offers a New High-Definition View". NASA. 2006-02-28. Retrieved 2007-01-03.

[79] Vergano, Dan (1 December 2010). "Universe holds billions more stars than previously thought". USA Today. Retrieved 2010-12-14.

[:0-80] Earth's new address: 'Solar System, Milky Way, Laniakea' / Nature

[81] ttp://www.universetoday.com/30286/local-group/

[82] "Astronomers discover largest known structure in the universe is ... a big hole". The Guardian. 20 April 2015.

[83] "WMAP 9 Year Mission Results". wmap.gsfc.nasa.gov. Retrieved 2015-07-26.

[84] "WMAP- Content of the Universe". map.gsfc.nasa.gov. Retrieved 2015-07-26.

[85] "Content of the Universe - WMAP 9yr Pie Chart". wmap.gsfc.nasa.gov. Retrieved 2015-07-26.

[86] Hinshaw, Gary (November 29, 2006). "New Three Year Results on the Oldest Light in the Universe". NASA WMAP. Retrieved 2006-08-10.

[87] Hinshaw, Gary (December 15, 2005). "Tests of the Big Bang: The CMB". NASA WMAP. Retrieved 2007-01-09.

[88] Rindler, p. 202.

[89] "Dark Energy". Hyperphysics. Retrieved January 4, 2014. ^{[unreliable source?]}

[carroll-90] Carroll, Sean (2001). "The cosmological constant". Living Reviews in Relativity 4. Retrieved 2006-09-28.

[planckcam-91] "Planck captures portrait of the young Universe, revealing earliest light". University of Cambridge. 21 March 2013. Retrieved 21 March 2013.

[Davies2-92] P. Davies (1992). The New Physics: A Synthesis. Cambridge University Press. p. 1. ISBN 0-521-43831-4.

[Hooft-93] G. 't Hooft (1997). In search of the ultimate building blocks. Cambridge University Press. p. 6. ISBN 0-521-57883-3.

[RHIC-94] "RHIC Scientists Serve Up "Perfect" Liquid" (Press release). Brookhaven National Laboratory. 18 April 2005. Retrieved 2009-09-15.

[PFIp1-3-95] Sylvie Braibant; Giorgio Giacomelli; Maurizio Spurio (2012). Particles and Fundamental Interactions: An Introduction to Particle Physics (2nd ed.). Springer. pp. 1–3. ISBN 978-94-007-2463-1.

[96] Strobel, Nick (May 23, 2001). "The Composition of Stars". Astronomy Notes. Retrieved 2007-01-04.
"Have physical constants changed with time?". Astrophysics (Astronomy Frequently Asked Questions). Retrieved 2007-01-04.

[97] R. Oerter (2006). The Theory of Almost Everything: The Standard Model, the Unsung Triumph of Modern Physics (Kindle ed.). Penguin Group. p. 2. ISBN 0-13-236678-9.

[98] "Lepton (physics)". Encyclopædia Britannica. Retrieved 2010-09-29.

[99] Harari, H. (1977). "Beyond charm". In Balian, R.; Llewellyn-Smith, C.H. Weak and Electromagnetic Interactions at High Energy, Les Houches, France, Jul 5- Aug 14, 1976. Les Houches Summer School Proceedings 29. North-Holland. p. 613.

[100] Harari H. (1977). "Three generations of quarks and leptons" (PDF). In E. van Goeler, Weinstein R. (eds.). Proceedings of the XII Rencontre de Moriond. p. 170. SLAC-PUB-1974.

[101] "Experiment confirms famous physics model" (Press release). MIT News Office. 18 April 2007.

[102] The Timescale of Creation

[103] Veltman, Martinus (2003). Facts and Mysteries in Elementary Particle Physics. World Scientific. ISBN 981-238-149-X.

[OnyisiFAQ-104] Onyisi, P. (23 October 2012). "Higgs boson FAQ". University of Texas ATLAS group. Retrieved 2013-01-08.

[strasslerFAQ2-105] Strassler, M. (12 October 2012). "The Higgs FAQ 2.0". ProfMattStrassler.com. Retrieved 2013-01-08. [Q] Why do particle physicists care so much about the Higgs particle?
[A] Well, actually, they don’t. What they really care about is the Higgs field, because it is so important. [emphasis in original]

[106] Ray d'Inverno (1992), Introducing Einstein's Relativity, Clarendon Press, chp. 22.8 Geometry of 3-spaces of constant curvature, p.319ff, ISBN 0-19-859653-7

[electro-107] Albert Einstein (1905) "Zur Elektrodynamik bewegter Körper", Annalen der Physik 17: 891; English translation On the Electrodynamics of Moving Bodies by George Barker Jeffery and Wilfrid Perrett (1923); Another English translation On the Electrodynamics of Moving Bodies by Megh Nad Saha (1920).

[108] Tom Roberts and Siegmar Schleif (October 2007). "What is the experimental basis of Special Relativity?". Usenet Physics FAQ. Retrieved 2008-09-17.

[relativity-109] Albert Einstein (2001). Relativity: The Special and the General Theory (Reprint of 1920 translation by Robert W. Lawson ed.). Routledge. p. 48. ISBN 0-415-25384-5.

[Feynman-110] Richard Phillips Feynman (1998). Six Not-so-easy Pieces: Einstein's relativity, symmetry, and space–time (Reprint of 1995 ed.). Basic Books. p. 68. ISBN 0-201-32842-9.

[111] O'Connor, J.J. and E.F. Robertson (1996), "General relativity". Mathematical Physics index, School of Mathematics and Statistics, University of St. Andrews, Scotland, May, 1996. Retrieved 2015-02-04.

[zeilik_cosmology-112] Zeilik, Michael; Gregory, Stephen A. (1998). "25-2". Introductory Astronomy & Astrophysics (4th ed.). Saunders College Publishing. ISBN 0030062284.

[113] Friedmann A. (1922). "Über die Krümmung des Raumes" (PDF). Zeitschrift für Physik 10 (1): 377–386. Bibcode:1922ZPhy...10..377F. doi:10.1007/BF01332580.

[114] "Cosmic Detectives". The European Space Agency (ESA). 2013-04-02. Retrieved 2013-04-15.

[115] Munitz MK (1959). "One Universe or Many?". Journal of the History of Ideas 12 (2): 231–255. doi:10.2307/2707516. JSTOR 2707516.

[chaotic_inflation-116] Linde A. (1986). "Eternal chaotic inflation". Mod. Phys. Lett. A1 (2): 81–85. Bibcode:1986MPLA....1...81L. doi:10.1142/S0217732386000129.
Linde A. (1986). "Eternally existing self-reproducing chaotic inflationary Universe" (PDF). Phys. Lett. B175 (4): 395–400. Bibcode:1986PhLB..175..395L. doi:10.1016/0370-2693(86)90611-8. Retrieved 2011-03-17.

[TegmarkPUstaple-117] Tegmark M. (2003). "Parallel universes. Not just a staple of science fiction, other universes are a direct implication of cosmological observations". Scientific American 288 (5): 40–51. doi:10.1038/scientificamerican0503-40. PMID 12701329.

[118] Tegmark, Max (2003). J. D. Barrow; P.C.W. Davies; C.L. Harper, eds. "Parallel Universes". Scientific American: "Science and Ultimate Reality: from Quantum to Cosmos", honoring John Wheeler's 90th birthday (Cambridge University Press): 2131. arXiv:astro-ph/0302131. Bibcode:2003astro.ph..2131T. doi:10.1038/scientificamerican0503-40.

[EllisScA-119] Ellis G. F (2011). "Does the Multiverse Really Exist?". Scientific American 305 (2): 38–43. doi:10.1038/scientificamerican0811-38.

[120] Clara Moskowitz (August 12, 2011). "Weird! Our Universe May Be a 'Multiverse,' Scientists Say". livescience.

[toa-121] Mark Isaak (ed.) (2005). "CI301: The Anthropic Principle". Index to Creationist Claims. TalkOrigins Archive. Retrieved 2007-10-31.

[122] Gernet, J. (1993–1994). "Space and time: Science and religion in the encounter between China and Europe". Chinese Science 11. pp. 93–102.

[123] Ng, Tai (2007). "III.3". Chinese Culture, Western Culture: Why Must We Learn from Each Other?. iUniverse, Inc.

[Blandford-124] Blandford R. D. "A century of general relativity: Astrophysics and cosmology". Science 347 (6226): 103–108. Bibcode:2015Sci...347.1103B. doi:10.1126/science.aaa4033.

[125] Leeming, David A. (2010). Creation Myths of the World. ABC-CLIO. p. xvii. ISBN 978-1-59884-174-9. In common usage the word 'myth' refers to narratives or beliefs that are untrue or merely fanciful; the stories that make up national or ethnic mythologies describe characters and events that common sense and experience tell us are impossible. Nevertheless, all cultures celebrate such myths and attribute to them various degrees of literal or symbolic truth.

[126] (Henry Gravrand, "La civilisation Sereer -Pangool") [in] Universität Frankfurt am Main, Frobenius-Institut, Deutsche Gesellschaft für Kulturmorphologie, Frobenius Gesellschaft, "Paideuma: Mitteilungen zur Kulturkunde, Volumes 43–44", F. Steiner (1997), pp. 144–5, ISBN 3515028420

[127] B. Young, Louise. The Unfinished Universe. Oxford University Press. p. 21.

[128] Will Durant, Our Oriental Heritage:

"Two systems of Hindu thought propound physical theories suggestively similar to those of Greece. Kanada, founder of the Vaisheshika philosophy, held that the world is composed of atoms as many in kind as the various elements. The Jains more nearly approximated to Democritus by teaching that all atoms were of the same kind, producing different effects by diverse modes of combinations. Kanada believed light and heat to be varieties of the same substance; Udayana taught that all heat comes from the Sun; and Vachaspati, like Newton, interpreted light as composed of minute particles emitted by substances and striking the eye."

[129] Stcherbatsky, F. Th. (1930, 1962), Buddhist Logic, Volume 1, p. 19, Dover, New York:

"The Buddhists denied the existence of substantial matter altogether. Movement consists for them of moments, it is a staccato movement, momentary flashes of a stream of energy... "Everything is evanescent",... says the Buddhist, because there is no stuff... Both systems [Sānkhya, and later Indian Buddhism] share in common a tendency to push the analysis of existence up to its minutest, last elements which are imagined as absolute qualities, or things possessing only one unique quality. They are called "qualities" (guna-dharma) in both systems in the sense of absolute qualities, a kind of atomic, or intra-atomic, energies of which the empirical things are composed. Both systems, therefore, agree in denying the objective reality of the categories of Substance and Quality,... and of the relation of Inference uniting them. There is in Sānkhya philosophy no separate existence of qualities. What we call quality is but a particular manifestation of a subtle entity. To every new unit of quality corresponds a subtle quantum of matter which is called guna, "quality", but represents a subtle substantive entity. The same applies to early Buddhism where all qualities are substantive... or, more precisely, dynamic entities, although they are also called dharmas ('qualities')."

[1908DeMundo-130] Aristotle; Forster, E. S. (Edward Seymour), 1879-1950; Dobson, J. F. (John Frederic), 1875-1947 (1914). De Mundo. p. 2.

[131] Boyer, C. (1968) A History of Mathematics. Wiley, p. 54.

[132] Neugebauer, Otto E. (1945). "The History of Ancient Astronomy Problems and Methods". Journal of Near Eastern Studies 4 (1): 1–38. doi:10.1086/370729. JSTOR 595168. the Chaldaean Seleucus from Seleucia

[133] Sarton, George (1955). "Chaldaean Astronomy of the Last Three Centuries B. C". Journal of the American Oriental Society 75 (3): 166–173 (169). doi:10.2307/595168. JSTOR 595168. the heliocentrical astronomy invented by Aristarchos of Samos and still defended a century later by Seleucos the Babylonian

[134] William P. D. Wightman (1951, 1953), The Growth of Scientific Ideas, Yale University Press p. 38, where Wightman calls him Seleukos the Chaldean.

[135] Lucio Russo, Flussi e riflussi, Feltrinelli, Milano, 2003, ISBN 88-07-10349-4.

[136] Bartel (1987, p. 527)

[137] Bartel (1987, pp. 527–9)

[138] Bartel (1987, pp. 529–34)

[139] Bartel (1987, pp. 534–7)

[Nasr-140] Nasr, Seyyed H. (1993) [1964]. An Introduction to Islamic Cosmological Doctrines (2nd ed.). 1st edition by Harvard University Press, 2nd edition by State University of New York Press. pp. 135–6. ISBN 0-7914-1515-5.

[141] Misner, Thorne and Wheeler, p. 754.

[142] Abhishek Parakh (2006). "A Note on Aryabhata's Principle of Relativity". arXiv:physics/0610095.

[143] Ālī, Ema Ākabara. Science in the Quran 1. Malik Library. p. 218.

[144] Ragep, F. Jamil (2001), "Tusi and Copernicus: The Earth's Motion in Context", Science in Context (Cambridge University Press) 14 (1–2): 145–163, doi:10.1017/s0269889701000060

[Misner-p755-145] Misner, Thorne and Wheeler, p. 755–756.

[m756-146] Misner, Thorne and Wheeler, p. 756.

[147] Cheseaux JPL (1744). Traité de la Comète. Lausanne. pp. 223ff. . Reprinted as Appendix II in Dickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press. ISBN 978-0-262-54003-2.

[148] Olbers HWM (1826). "Unknown title". Bode's Jahrbuch 111. . Reprinted as Appendix I in Dickson FP (1969). The Bowl of Night: The Physical Universe and Scientific Thought. Cambridge, MA: M.I.T. Press. ISBN 978-0-262-54003-2.

[149] Jeans, J. H. (1902). "The Stability of a Spherical Nebula" (PDF). Philosophical Transactions of the Royal Society A 199 (312–320): 1–53. Bibcode:1902RSPTA.199....1J. doi:10.1098/rsta.1902.0012. JSTOR 90845. Retrieved 2011-03-17.

[150] Misner, Thorne and Wheeler, p. 757.

[einstein_1917-151] Einstein, A (1917). "Kosmologische Betrachtungen zur allgemeinen Relativitätstheorie". Preussische Akademie der Wissenschaften, Sitzungsberichte. 1917. (part 1): 142–152.

WMAP image of cosmic background radiation
Age	13.798 ± 0.037 billion years^[1]
Diameter	Possibly infinite; at least 91 billion light-years (28×10^⁹ pc)^[2]
Mass (ordinary matter)	At least 10⁵³ kg^[3]
Average density	4.5 x 10⁻³¹ g/cm³^[4]
Average temperature	2.72548 K^[5]
Main Contents	Ordinary (baryonic) matter (4.9%), dark matter (26.8%), dark energy (68.3%)^[6]
Shape	Flat with only a 0.4% margin of error^[7]

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