How did big bang started.No christian answers that god made the universe?

Answer 1

I don't believe God made the universe if that makes you feel better,

In physical cosmology, the Big Bang is the scientific theory that the universe emerged from a tremendously dense and hot state about 13.7 billion years ago. The theory is based on the observations indicating the expansion of space (in accord with the Robertson-Walker model of general relativity) as indicated by the Hubble redshift of distant galaxies taken together with the cosmological principle.

Extrapolated into the past, these observations show that the universe has expanded from a state in which all the matter and energy in the universe was at an immense temperature and density. Physicists do not widely agree on what happened before this, although general relativity predicts a gravitational singularity (for reporting on some of the more notable speculation on this issue, see cosmogony).

The term Big Bang is used both in a narrow sense to refer to a point in time when the observed expansion of the universe (Hubble's law) began — calculated to be 13.7 billion (1.37 × 1010) years ago (±2%) — and in a more general sense to refer to the prevailing cosmological paradigm explaining the origin and expansion of the universe, as well as the composition of primordial matter through nucleosynthesis as predicted by the Alpher-Bethe-Gamow theory.[1]

From this model, George Gamow in 1948 was able to predict, at least qualitatively, the existence of cosmic microwave background radiation (CMB).[2] The CMB was discovered in 1964[3] and further corroborated the Big Bang theory, giving it an additional advantage over its chief rival, the steady state theory.[4]

Physical cosmology

Age of the universe
Big Bang
Comoving distance
Cosmic microwave background
Dark energy
Dark matter
FLRW metric
Friedmann equations
Galaxy formation
Hubble's law
Inflation
Large-scale structure
Lambda-CDM model
Metric expansion of space
Nucleosynthesis
Observable universe
Redshift
Shape of the universe
Structure formation
Timeline of the Big Bang
Timeline of cosmology
Ultimate fate of the universe
Universe

Related topics
Astrophysics
General relativity
Particle physics
Quantum gravity

This box: view • talk • edit
Contents [hide]
1 History
2 Overview
3 Theoretical underpinnings
4 Observational evidence
4.1 Hubble's law expansion
4.2 Cosmic microwave background radiation
4.3 Abundance of primordial elements
4.4 Galactic evolution and distribution
5 Features, issues and problems
5.1 Horizon problem
5.2 Flatness problem
5.3 Magnetic monopoles
5.4 Baryon asymmetry
5.5 Globular cluster age
5.6 Dark matter
5.7 Dark energy
6 The future according to the Big Bang theory
7 Speculative physics beyond the Big Bang
8 Philosophical and religious interpretations
9 Notes
10 External links and references
10.1 Big Bang overviews
10.2 Religion and philosophy
10.3 Research articles



[edit] History
Main article: History of the Big Bang
The Big Bang theory developed from observations of the structure of the universe and theoretical considerations. Observationally, it was determined that most spiral nebulae were receding from Earth, but those who made the observation weren't aware of the cosmological implications, nor that the supposed nebulae were actually galaxies outside our own Milky Way.[5] In 1927, Georges Lemaître, a Belgian Roman Catholic priest, independently derived the Friedmann-Lemaître-Robertson-Walker equations from Albert Einstein's equations of general relativity and proposed, on the basis of the recession of spiral nebulae, that the universe began with the "explosion" of a "primeval atom"—what was later called the Big Bang.[6]

In 1929, Edwin Hubble provided an observational basis for Lemaître's theory. He discovered that, seen from Earth, light from other galaxies is redshifted in direct proportion to their distance from the Earth. This fact is now known as Hubble's law.[7][8] Given the cosmological principle whereby the universe, when viewed on sufficiently large distance scales, has no preferred directions or preferred places, Hubble's law suggested that the universe was expanding, contradicting the infinite and unchanging static universe scenario developed by Einstein.[9]


Artist's depiction of the WMAP satellite gathering data to help scientists understand the Big Bang.This idea allowed for two main opposing possibilities. One was Lemaître's Big Bang theory, advocated and developed by George Gamow. The other possibility was Fred Hoyle's steady state model in which new matter would be created as the galaxies moved away from each other. In this model, the universe is roughly the same at any point in time.[10] It was actually Hoyle who coined the name of Lemaître's theory, referring to it sarcastically as "this big bang idea" during a program broadcast on March 28, 1949, by the BBC Third Programme. Hoyle repeated the term in further broadcasts in early 1950, as part of a series of five lectures entitled The Nature of Things. The text of each lecture was published in The Listener a week after the broadcast, the first time that the term "big bang" appeared in print.[11] While Hoyle's "steady state" and Lemaître's "Big Bang" were the two most popular models used to explain Hubble's observations, other ideas were also proposed as well. Some of these alternatives included the Milne model,[12] Richard Tolman's oscillatory universe,[13] and Fritz Zwicky's tired light hypothesis.[14]

For a number of years, the support for the "steady state" and "Big Bang" theories was evenly divided. However, the observational evidence began to support the idea that the universe evolved from a hot dense state. Since the discovery of the cosmic microwave background radiation in 1964, it has been regarded as the best theory of the origin and evolution of the cosmos. Virtually all theoretical work in cosmology now involves extensions and refinements to the basic Big Bang theory. Much of the current work in cosmology includes understanding how galaxies form in the context of the Big Bang, understanding what happened at the Big Bang and reconciling observations with the basic theory.

Huge advances in Big Bang cosmology were made in the late 1990s and the early 21st century as a result of major advances in telescope technology in combination with large amounts of satellite data such as that from COBE, the Hubble Space Telescope and WMAP. Such data have allowed cosmologists to calculate many of the parameters of the Big Bang to a new level of precision and led to the unexpected discovery that the expansion of the universe appears to be accelerating. (See dark energy.)

See also: Timeline of cosmology


[edit] Overview
A graphical timeline is available here:
Graphical timeline of the Big BangBased on measurements of the expansion of the universe using Type 1a supernovae, measurements of the lumpiness of the cosmic microwave background, and measurements of the correlation function of galaxies, the universe has a calculated age of 13.7 ± 0.2 billion years. The agreement of these three independent measurements is considered strong evidence for the so-called ΛCDM model that describes the detailed nature of the contents of the universe.

The early universe was filled homogeneously and isotropically with an incredibly high energy density and concomitantly huge temperatures and pressures. It expanded and cooled, going through phase transitions analogous to the condensation of steam or freezing of water as it cools, but related to elementary particles.

Approximately 10−35 seconds after the Planck epoch a phase transition caused the universe to experience exponential growth during a period called cosmic inflation. After inflation stopped, the material components of the universe were in the form of a quark-gluon plasma (also including all other particles—and perhaps experimentally produced recently as a quark-gluon liquid [3]) in which the constituent particles were all moving relativistically. As the universe continued growing in size, the temperature dropped. At a certain temperature, by an as-yet-unknown transition called baryogenesis, the quarks and gluons combined into baryons such as protons and neutrons, somehow producing the observed asymmetry between matter and antimatter. Still lower temperatures led to further symmetry breaking phase transitions that put the forces of physics and elementary particles into their present form. Later, some protons and neutrons combined to form the universe's deuterium and helium nuclei in a process called Big Bang nucleosynthesis. As the universe cooled, matter gradually stopped moving relativistically and its rest mass energy density came to gravitationally dominate that of radiation. After about 300,000 years the electrons and nuclei combined into atoms (mostly hydrogen); hence the radiation decoupled from matter and continued through space largely unimpeded. This relic radiation is the cosmic microwave background.

Over time, the slightly denser regions of the nearly uniformly distributed matter gravitationally attracted nearby matter and thus grew even denser, forming gas clouds, stars, galaxies, and the other astronomical structures observable today. The details of this process depend on the amount and type of matter in the universe. The three possible types are known as cold dark matter, hot dark matter, and baryonic matter. The best measurements available (from WMAP) show that the dominant form of matter in the universe is cold dark matter. The other two types of matter make up less than 20% of the matter in the universe.

The universe today appears to be dominated by a mysterious form of energy known as dark energy. Approximately 70% of the total energy density of today's universe is in this form. This dark energy causes the expansion of the universe to deviate from a linear velocity-distance relationship, observed as a faster than expected expansion at very large distances. Dark energy in its simplest formulation takes the form of a cosmological constant term in Einstein's field equations of general relativity, but its composition is unknown and, more generally, the details of its equation of state and relationship with the standard model of particle physics continue to be investigated both observationally and theoretically.

All these observations are encapsulated in the ΛCDM model of cosmology, which is a mathematical model of the Big Bang with six free parameters. Mysteries appear as one looks closer to the beginning, when particle energies were higher than can yet be studied by experiment. There is no compelling physical model for the first 10−33 seconds of the universe, before the phase transition that grand unification theory predicts. At the "first instant", Einstein's theory of gravitation predicts a gravitational singularity where densities become infinite.[15] To resolve this paradox, a theory of quantum gravitation is needed. Understanding this period of the history of the universe is one of the greatest unsolved problems in physics.

See also: Timeline of the Big Bang


[edit] Theoretical underpinnings
As it stands today, the Big Bang is dependent on three assumptions:

The universality of physical laws
The cosmological principle
The Copernican principle
When first developed, these ideas were simply taken as postulates, but today there are efforts underway to test each of them. Tests of the universality of physical laws have found that the largest possible deviation of the fine structure constant over the age of the universe is of order 10-5.[16] The isotropy of the universe that defines the Cosmological Principle has been tested to a level of 10-5 and the universe has been measured to be homogeneous on the largest scales to the 10% level.[17] There are efforts underway to test the Copernican Principle by means of looking at the interaction of galaxy groups and clusters with the CMB through the Sunyaev-Zel'dovich effect to a level of 1% accuracy.[18]

The Big Bang theory uses Weyl's postulate to measure time unambiguously at any point as the "time since the Planck epoch". Measurements in this system rely on conformal coordinates in which so-called comoving distances and conformal times remove the expansion of the universe, parameterized by the cosmological scale factor, from consideration of spacetime measurements. The comoving distances and conformal times are defined so that objects moving with the cosmological flow are always the same comoving distance apart and the particle horizon or observational limit of the local universe is set by the conformal time.

As the universe can be described by such coordinates, the Big Bang is not an explosion of matter moving outward to fill an empty universe; what is expanding is space itself. It is this expansion that causes the physical distance between any two fixed points in our universe to increase. Objects that are bound together (for example, by gravity) do not expand with spacetime's expansion because the physical laws that govern them are assumed to be uniform and independent of the metric expansion. Moreover, the expansion of the universe on today's local scales is so small that any dependence of physical laws on the expansion is unmeasurable by current techniques.


[edit] Observational evidence
It is generally stated that there are three observational pillars that support the Big Bang theory of cosmology. These are the Hubble-type expansion seen in the redshifts of galaxies, the detailed measurements of the cosmic microwave background, and the abundance of light elements. (See Big Bang nucleosynthesis.) Additionally, the observed correlation function of large-scale structure of the cosmos fits well with standard Big Bang theory.


[edit] Hubble's law expansion
Main article: Hubble's law

Hubble's original data from his 1929 paper.[19]Observations of distant galaxies and quasars show that these objects are redshifted, meaning that the light emitted from them has been shifted to longer wavelengths. This is seen by taking a frequency spectrum of the objects and then matching the spectroscopic pattern of emission lines or absorption lines corresponding to atoms of the chemical elements interacting with the light. From this analysis, a redshift corresponding to a Doppler shift for the radiation can be measured which is explained by a recessional velocity. When the recessional velocities are plotted against the distances to the objects, a linear relationship, known as Hubble's law, is observed:


where

v is the recessional velocity of the galaxy or other distant object
D is the distance to the object and
H0 is Hubble's constant, measured to be (70 +2.4/-3.2) km/s/Mpc by the WMAP probe.[20]
The Hubble's law observation has two possible explanations. One is that we are at the center of an explosion of galaxies, a position which is untenable given the Copernican principle. The second explanation is that the universe is uniformly expanding everywhere as a unique property of spacetime. This type of universal expansion was developed mathematically in the context of general relativity well before Hubble made his analysis and observations, and it remains the cornerstone of the Big Bang theory as developed by Friedmann-Lemaître-Robertson-Walker.




celia grahm


[edit] Cosmic microwave background radiation
Main article: Cosmic microwave background radiation

WMAP image of the cosmic microwave background radiationThe Big Bang theory predicted the existence of the cosmic microwave background radiation or CMB which is composed of photons first emitted during baryogenesis. Because the early universe was in thermal equilibrium, the temperature of the radiation and the plasma were equal until the plasma recombined. Before atoms formed, radiation was constantly absorbed and re-emitted in a process called Compton scattering: the early universe was opaque to light. However, cooling due to the expansion of the universe allowed the temperature to eventually fall below 3,000 K at which point electrons and nuclei combined to form atoms and the primordial plasma turned into a neutral gas. This is known as photon decoupling. A universe with only neutral atoms allows radiation to travel largely unimpeded.

Because the early universe was in thermal equilibrium, the radiation from this time had a blackbody spectrum and freely streamed through space until today, becoming redshifted because of the Hubble expansion. This reduces the high temperature of the blackbody spectrum. The radiation should be observable at every point in the universe to come from all directions of space.

In 1964, Arno Penzias and Robert Wilson, while conducting a series of diagnostic observations using a new microwave receiver owned by Bell Laboratories, discovered the cosmic background radiation.[3] Their discovery provided substantial confirmation of the general CMB predictions—the radiation was found to be isotropic and consistent with a blackbody spectrum of about 3 K—and it pitched the balance of opinion in favor of the Big Bang hypothesis. Penzias and Wilson were awarded the Nobel Prize for their discovery.

In 1989, NASA launched the Cosmic Background Explorer satellite (COBE), and the initial findings, released in 1990, were consistent with the Big Bang's predictions regarding the CMB. COBE found a residual temperature of 2.726 K and determined that the CMB was isotropic to about one part in 105.[21] During the 1990s, CMB anisotropies were further investigated by a large number of ground-based experiments and the universe was shown to be almost geometrically flat by measuring the typical angular size (the size on the sky) of the anisotropies. (See shape of the universe.)

In early 2003, the results of the Wilkinson Microwave Anisotropy satellite (WMAP) were released, yielding what were at the time the most accurate values for some of the cosmological parameters. (See cosmic microwave background radiation experiments.) This satellite also disproved several specific cosmic inflation models, but the results were consistent with the inflation theory in general.[22]


[edit] Abundance of primordial elements
Main article: Big Bang nucleosynthesis
Using the Big Bang model it is possible to calculate the concentration of helium-4, helium-3, deuterium and lithium-7 in the universe as ratios to the amount of ordinary hydrogen, H.[23] All the abundances depend on a single parameter, the ratio of photons to baryons. The ratios predicted (by mass, not by number) are about 0.25 for 4He/H, about 10-3 for 2H/H, about 10-4 for 3He/H and about 10-9 for 7Li/H.

The measured abundances all agree with those predicted from a single value of the baryon-to-photon ratio. The agreement is relatively poor for 7Li and 4He, the two elements for which the systematic uncertainties are least understood. This is considered strong evidence for the Big Bang, as the theory is the only known explanation for the relative abundances of light elements.[24] Indeed there is no obvious reason outside of the Big Bang that, for example, the young universe (i.e., before star formation, as determined by studying matter essentially free of stellar nucleosynthesis products) should have more helium than deuterium or more deuterium than 3He, and in constant ratios, too.


[edit] Galactic evolution and distribution
Main articles: Large-scale structure of the cosmos, Structure formation, and Galaxy formation and evolution
Detailed observations of the morphology and distribution of galaxies and quasars provide strong evidence for the Big Bang. A combination of observations and theory suggest that the first quasars and galaxies formed about a billion years after the Big Bang, and since then larger structures have been forming, such as galaxy clusters and superclusters. Populations of stars have been aging and evolving, so that distant galaxies (which are observed as they were in the early universe) appear very different from nearby galaxies (observed in a more recent state). Moreover, galaxies that formed relatively recently appear markedly different from galaxies formed at similar distances but shortly after the Big Bang. These observations are strong arguments against the steady-state model. Observations of star formation, galaxy and quasar distributions, and larger structures agree well with Big Bang simulations of the formation of structure in the universe and are helping to complete details of the theory.[25]


[edit] Features, issues and problems
While currently there are very few researchers who doubt the Big Bang occurred, in the past the community was divided between supporters of the Big Bang and supporters of alternative cosmological models. Throughout the historical development of the subject, problems with the Big Bang theory were posed in the context of a scientific controversy regarding which model could best describe the cosmological observations (see history section above). With the overwhelming consensus in the community today supporting the Big Bang model, many of these problems are remembered as being mainly of historical interest; the solutions to them have been obtained either through modifications to the theory or as the result of better observations. Other issues, such as the cuspy halo problem and the dwarf galaxy problem of cold dark matter, are not considered to be fatal as they can be addressed through further refinements of the theory.

The Big Bang model admits very exotic physical phenomena that include dark matter, dark energy, and cosmic inflation which rely on conditions and physics that have not yet been observed in terrestrial laboratory experiments. While explanations for such phenomena remain at the frontiers of inquiry in physics, independent observations of Big Bang nucleosynthesis, the cosmic microwave background, large scale structure and Type Ia supernovae strongly suggest the phenomena are important and real cosmological features of our universe. The gravitational effects of these features are understood observationally and theoretically but they have not yet been successfully incorporated into the Standard Model of particle physics. Though some aspects of the theory remain inadequately explained by fundamental physics, almost all cosmologists accept that the close agreement between Big Bang theory and observation have firmly established all the basic parts of the theory.

The following is a short list of Big Bang "problems" and puzzles:


[edit] Horizon problem
Main article: Horizon problem
The horizon problem results from the premise that information cannot travel faster than light, and hence two regions of space which are separated by a greater distance than the speed of light multiplied by the age of the universe cannot be in causal contact.[23] The observed isotropy of the cosmic microwave background (CMB) is problematic in this regard, because the horizon size at that time corresponds to a size that is about 2 degrees on the sky. If the universe has had the same expansion history since the Planck epoch, there is no mechanism to cause these regions to have the same temperature.

A resolution to this apparent inconsistency is offered by inflationary theory in which a homogeneous and isotropic scalar energy field dominates the universe at a time 10-35 seconds after the Planck epoch. During inflation, the universe undergoes exponential expansion, and regions in causal contact expand so as to be beyond each other's horizons. Heisenberg's uncertainty principle predicts that during the inflationary phase there would be quantum thermal fluctuations, which would be magnified to cosmic scale. These fluctuations serve as the seeds of all current structure in the universe. After inflation, the universe expands according to Hubble's law, and regions that were out of causal contact come back into the horizon. This explains the observed isotropy of the CMB. Inflation predicts that the primordial fluctuations are nearly scale invariant and Gaussian which has been accurately confirmed by measurements of the CMB.


[edit] Flatness problem

The overall geometry of the universe is determined by whether the Omega cosmological parameter is less than, equal to or greater than 1. From top to bottom: geometry in a closed universe, an open universe and a flat universe.Main article: Flatness problem
The flatness problem is an observational problem that results from considerations of the geometry associated with a Friedmann-Lemaître-Robertson-Walker metric.[23] In general, the universe can have three different kinds of geometries: hyperbolic geometry, Euclidean geometry, or elliptic geometry. The geometry is determined by the total energy density of the universe (as measured by means of the stress-energy tensor): hyperbolic results from a density less than the critical density, elliptic from a density greater than the critical density, and Euclidean from exactly the critical density. The universe is required to be within one part in 1015 of the critical density in its earliest stages. Any greater deviation would have caused either a Heat Death or a Big Crunch, and the universe would not exist as it does today.

A possible resolution to this problem is again offered by inflationary theory. During the inflationary period, spacetime expanded to such an extent that any residual curvature associated with it would have been smoothed out to a high degree of precision. Thus, it is believed that inflation drove the universe to be very nearly spatially flat.


[edit] Magnetic monopoles
The magnetic monopole objection was raised in the late 1970s. Grand unification theories predicted point defects in space that would manifest as magnetic monopoles with a density much higher than was consistent with observations, given that searches have never found any monopoles. This problem is also resolvable by cosmic inflation, which removes all point defects from the observable universe in the same way that it drives the geometry to flatness.[23]


[edit] Baryon asymmetry
It is not yet understood why the universe has more matter than antimatter.[23] It is generally assumed that when the universe was young and very hot, it was in statistical equilibrium and contained equal numbers of baryons and anti-baryons. However, observations suggest that the universe, including its most distant parts, is made almost entirely of matter. An unknown process called baryogenesis created the asymmetry. For baryogenesis to occur, the Sakharov conditions, which were laid out by Andrei Sakharov, must be satisfied. They require that baryon number be not conserved, that C-symmetry and CP-symmetry be violated, and that the universe depart from thermodynamic equilibrium.[26] All these conditions occur in the Standard Model, but the effect is not strong enough to explain the present baryon asymmetry. [27] Experiments taking place at CERN near Geneva seek to trap enough anti-hydrogen to compare its spectrum with hydrogen. Any difference would be evidence of a CPT symmetry violation and therefore a Lorentz violation.


[edit] Globular cluster age
In the mid-1990s, observations of globular clusters appeared to be inconsistent with the Big Bang. Computer simulations that matched the observations of the stellar populations of globular clusters suggested that they were about 15 billion years old, which conflicted with the 13.7-billion-year age of the universe. This issue was generally resolved in the late 1990s when new computer simulations, which included the effects of mass loss due to stellar winds, indicated a much younger age for globular clusters.[28] There still remain some questions as to how accurately the ages of the clusters are measured, but it is clear that these objects are some of the oldest in the universe.


[edit] Dark matter
Main article: Dark matter

A pie chart indicating the proportional composition of different energy-density components of the universe, according to the best ΛCDM model fits. Roughly ninety-five percent is in the exotic forms of dark matter and dark energy.During the 1970s and 1980s, various observations (notably of galactic rotation curves) showed that there was not sufficient visible matter in the universe to account for the apparent strength of gravitational forces within and between galaxies. This led to the idea that up to 90% of the matter in the universe is not normal or baryonic matter but rather dark matter. In addition, assuming that the universe was mostly normal matter led to predictions that were strongly inconsistent with observations. In particular, the universe is far less lumpy and contains far less deuterium than can be accounted for without dark matter. While dark matter was initially controversial, it is now a widely accepted part of standard cosmology due to observations of the anisotropies in the CMB, galaxy cluster velocity dispersions, large-scale structure distributions, gravitational lensing studies, and x-ray measurements from galaxy clusters. In August 2006, dark matter was definitively observed[29][30] through measurements of colliding galaxies in the Bullet Cluster. This and other detections of dark matter are only sensitive to its gravitational signature; no dark matter particles have yet been observed in laboratories. However, there are many particle physics candidates for dark matter, and several projects to detect them directly are underway.


[edit] Dark energy
Main article: Dark energy
In the 1990s, detailed measurements of the mass density of the universe revealed a value that was 30% that of the critical density.[9] Since the universe is very nearly spatially flat, as is indicated by measurements of the cosmic microwave background, about 70% of the energy density of the universe was left unaccounted for. This mystery now appears to be connected to another one: Independent measurements of Type Ia supernovae have revealed that the expansion of the universe is undergoing a non-linear acceleration. To explain this acceleration, general relativity requires that much of the universe consist of an energy component with large negative pressure. This dark energy is now thought to make up the missing 70%. Its nature remains one of the great mysteries of the Big Bang. Possible candidates include a scalar cosmological constant and quintessence. Observations to help understand this are ongoing. Results from WMAP in 2006 indicate that the universe is 74% dark energy, 22% dark matter, and 4% regular matter (see external link).


[edit] The future according to the Big Bang theory
Main article: Ultimate fate of the universe
Before observations of dark energy, cosmologists considered two scenarios for the future of the universe. If the mass density of the universe is above the critical density, then the universe would reach a maximum size and then begin to collapse. It would become denser and hotter again, ending with a state that was similar to that in which it started—a Big Crunch. Alternatively, if the density in the universe is equal to or below the critical density, the expansion would slow down, but never stop. Star formation would cease as the universe grows less dense. The average temperature of the universe would asymptotically approach absolute zero—a Big Freeze. Black holes would evaporate. The entropy of the universe would increase to the point where no organized form of energy could be extracted from it, a scenario known as heat death. Moreover, if proton decay exists, then hydrogen, the predominant form of baryonic matter in the universe today, would disappear, leaving only radiation.

Modern observations of accelerated expansion imply that more and more of the currently visible universe will pass beyond our event horizon and out of contact with us. The eventual result is not known. The ΛCDM model of the universe contains dark energy in the form of a cosmological constant. This theory suggests that only gravitationally bound systems, such as galaxies, would remain together, and they too would be subject to heat death, as the universe cools and expands. Other explanations of dark energy — so-called phantom energy theories — suggest that ultimately galaxy clusters and eventually galaxies themselves will be torn apart by the ever-increasing expansion in a so-called Big Rip.


[edit] Speculative physics beyond the Big Bang

A graphical representation of the expansion of the universe with the inflationary epoch represented as the dramatic expansion of the metric seen on the left. Image from WMAP press release, 2006. (Detail)While the Big Bang model is well established in cosmology, it is likely to be refined in the future. Little is known about the earliest universe, when inflation is hypothesized to have occurred. There may also be parts of the universe well beyond what can be observed in principle. In the case of inflation this is required: exponential expansion has pushed large regions of space beyond our observable horizon. It may be possible to deduce what happened when we better understand physics at very high energy scales. Speculations about this often involve theories of quantum gravitation.

Some proposals are:

models including the Hartle-Hawking boundary condition in which the whole of space-time is finite;
brane cosmology models, including brane inflation, in which inflation is due to the movement of branes in string theory; the pre-big bang model; the ekpyrotic model, in which the Big Bang is the result of a collision between branes; and the cyclic model, a variant of the ekpyrotic model in which collisions occur periodically.
chaotic inflation, in which inflation starts from random initial conditions for the universe.
Some of these scenarios are qualitatively compatible with one another. Each entails untested hypotheses.


[edit] Philosophical and religious interpretations
The Big Bang, as a scientific theory, is not based on any religion.[citation needed] However, it does have both theological and philosophical implications, since some religious interpretations and world views conflict with the Big Bang origin of the universe.

There are a number of interpretations of the Big Bang theory that go beyond science, some of them purporting to explain the cause of the Big Bang itself (first cause). These views have been criticized by some naturalist philosophers as being modern creation myths. Some people believe that the Big Bang theory is inconsistent with traditional views of creation such as that in Genesis, for example, while others, like astronomer Hugh Ross, believe that the Big Bang theory lends support to the idea of creation ex nihilo.[31]

Initially, many scientists rejected the Big Bang theory because they thought it was religious in nature. The prevailing view at the time was that the universe was eternal, having always existed. Some felt the idea that the universe had a beginning would imply a creator (see Kalam cosmological argument), which would be unscientific.[32] These connotations troubled astronomer Fred Hoyle and others, who developed the now discredited steady state theory as an alternative to the Big Bang which would allow for an eternal universe. Astrophysicist Arthur Eddington had no such qualms, arguing that evidence of a Big Bang and start to the universe made "religion possible for a reasonable man of science."[33]

The following is a list of various religious interpretations of the Big Bang theory:

A number of Christian and traditional Jewish sources have accepted the Big Bang as a possible description of the origin of the universe, interpreting it to allow for a philosophical first cause. Pope Pius XII was an enthusiastic proponent of the Big Bang even before the theory was scientifically well established and consequently the Roman Catholic Church has been a prominent advocate for the idea that creation ex nihilo can be interpreted as consistent with the Big Bang. This view is shared by many religious Jews in all branches of rabbinic Judaism. Some groups, such as the Kabbalah Centre, contend the Big Bang is also consistent with the teaching of creation according to Isaac Luria and Kabbalah. [34]
Some modern Islamic scholars believe that the Qur'an parallels the Big Bang in its account of creation, described as follows: "Do not the unbelievers see that the heavens and the earth were joined together as one unit of creation, before We clove them asunder?" (Ch:21,Ver:30). The claim has also been made that the Qur'an describes an expanding universe: "The heaven, We have built it with power. And verily, We are expanding it." (Ch:51,Ver:47).[35] Parallels with the Big Crunch and an oscillating universe have also been suggested: "On the day when We will roll up the heavens like the rolling up of the scroll for writings, as We originated the first creation, (so) We shall reproduce it; a promise (binding on Us); surely We will bring it about." (Ch:21,Ver:104).
Certain theistic branches of Hinduism, such as in Vaishnavism, conceive of a creation event with similarities to the Big Bang. For example in the third book of the Bhagavata Purana (primarily, chapters 10 and 26), describes a primordial state which bursts forth as the Great Vishnu glances over it, transforming into the active state of the sum-total of matter ("prakriti"). Other forms of Hinduism assert a universe without beginning or end.
Buddhism has a concept of universes that have no initial creation event, but instead go through infinitely repeated cycles of expansion, stability, destruction, and quiescence. The Big Bang, however, is not seen to be in conflict with this since there are ways to conceive an eternal creation and destruction of universes within the paradigm. A number of popular Zen philosophers were intrigued, in particular, by the concept of the oscillating universe.

[edit] Notes
^ R. A. Alpher, H. Bethe, G. Gamow, "The Origin of Chemical Elements,"Physical Review 73 (1948), 803.
^ G. Gamow, Nature 162 (1948), 680.
^ a b A. A. Penzias and R. W. Wilson, "A Measurement of Excess Antenna Temperature at 4080 Mc/s," Astrophysical Journal 142 (1965), 419.
^ R. H. Dicke, P. J. E. Peebles, P. G. Roll and D. T. Wilkinson, "Cosmic Black-Body Radiation," Astrophysical Journal 142 (1965), 414.
^ V. Slipher, paper presented to the American Astronomical Society, (1915).
^ G. Lemaître (1927). "Un Univers homogène de masse constante et de rayon croissant rendant compte de la vitesse radiale des nébuleuses extragalactiques". Annals of the Scientific Society of Brussels 47A: 41. Translated in: (1931) "A homogeneous universe of constant mass and growing radius accounting for the radial velocity of extragalactic nebulae". Monthly Notices of the Royal Astronomical Society 91: 483–490.. The "primeval atom" was introduced here: G. Lemaître, Nature 128 (1931) suppl.: 704.
^ Edwin Hubble (1929). "A relation between distance and radial velocity among extra-galactic nebulae". Proc. Nat. Acad. Sci. 15: 168–173.
^ E. Christianson. Edwin Hubble: Mariner of the Nebulae.
^ a b P. J. E. Peebles and Bharat Ratra (2003). "The cosmological constant and dark energy". Reviews of Modern Physics 75: 559–606.
^ F. Hoyle, '"A New Model for the Expanding universe", Monthly Notices of the Royal Astronomical Society, 108 (1948), 372.
^ The book in question can be downloaded here:[1]
^ E. A. Milne (1935). Relativity, Gravitation and World Structure. Oxford University Press.
^ R. C. Tolman (1934). Relativity, Thermodynamics, and Cosmology. Oxford: Clarendon Press. LCCN 340-32023. Reissued (1987) New York: Dover ISBN 0-486-65383-8.
^ Zwicky, F. 1929. On the Red Shift of Spectral Lines through Interstellar Space. PNAS 15:773-779. Abstract (ADS) Full article (PDF)
^ S. W. Hawking and G. F. R. Ellis, The large-scale structure of space-time (Cambridge, 1973).
^ A. V. Ivanchik, et al. "The fine-structure constant: a new observational limit on its cosmological variation and some theoretical consequences", Astronomy and Astrophysics 343 (1999) 439.
^ J. Goodman Physics Review D, 52 (1995) 1821.
^ Caltech Submillimeter Observatory has a program underway for measuring detail observations of the CMB to look for Sunyaev-Zel'dovich Effect correlations. [2]
^ Hubble, Edwin, "A Relation between Distance and Radial Velocity among Extra-Galactic Nebulae" (1929) Proceedings of the National Academy of Sciences of the United States of America, Volume 15, Issue 3, pp. 168-173 (Full article, PDF)
^ D. N. Spergel, et al. "First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Determination of cosmological parameters", Astrophysical Journal Supplement Series, 148 (2003) 175.
^ N.W. Boggess, et al. "The COBE Mission: Its Design and Performance Two Years after the launch," Astrophysical Journal, 397 (1992), 420.
^ D. N. Spergel et al. (WMAP collaboration) (March 2006). "Wilkinson Microwave Anisotropy Probe (WMAP) three year results: implications for cosmology".
^ a b c d e Kolb, Edward, Michael Turner (1988). The Early Universe. Addison-Wesley. ISBN 0-201-11604-9.
^ Steigman, Gary, Primordial Nucleosynthesis: Successes And Challenges arXiv:astro-ph/0511534.
^ E. Bertschinger (2001). "Cosmological perturbation theory and structure formation". Edmund Bertschinger (1998). "Simulations of structure formation in the universe". Annual Review of Astronomy and Astrophysics 36: 599–654.
^ A. D. Sakharov, "Violation of CP invariance, C asymmetry and baryon asymmetry of the universe," Pisma Zh. Eksp. Teor. Fiz. 5, 32 (1967), translated in JETP Lett. 5, 24 (1967).
^ See "Antimatter and the Big Bang" - A research paper about the big bang's antimatter problem. This paper won the grand prize in the Answers in Genesis War of the Worldviews Research Paper Challenge 2006.
^ A. A. Navabi and N. Riazi, "Is the Age Problem Resolved?" Journal of Astrophysics and Astronomy 24 (2003), 3.
^ A direct empirical proof of the existence of dark matter. Arxiv.
^ Dark Matter Observed. SLAC Today.
^ Hugh Ross, "Putting the Big Bang to the Test" Accessed Sept. 19, 2006
^ PBS, "Cosmology," Faith and Reason, Accessed Sept. 19, 2006
^ Gregg Easterbrook, "Was Life Begun By Chance? Not a Chance" Beliefnet.com, Accessed Sept. 19, 2006
^ The Kabbalah Centre, "Adam and Atom," Kabbalah On.., Accessed November 12, 2006
^ There are more prosaic translations of this verse which do not suggest an expanding universe including "And the heaven, We raised it high with power, and We are Makers of the vast extent." and "With power and skill did We construct the Firmament: for it is We Who create the vastness of space." However, Islamic scholars generally consider only the original Arabic text to be authoritative, and many state that the original Arabic text indeed indicates an expanding universe.

[edit] External links and references

[edit] Big Bang overviews
For an annotated list of textbooks and monographs, see physical cosmology.
Cosmology at the Open Directory Project
PBS.org, "From the Big Bang to the End of the universe. The Mysteries of Deep Space Timeline"
"Welcome to the History of the universe". Penny Press Ltd.
Cambridge University Cosmology, "The Hot Big Bang Model". Includes a discussion of the problems with the Big Bang.
Smithsonian Institution, "UNIVERSE! - The Big Bang and what came before".
D'Agnese, Joseph, "The last Big Bang man left standing, physicist Ralph Alpher devised Big Bang Theory of universe". Discover, July 1999.
Felder, Gary, "The Expanding universe".
LaRocco, Chris and Blair Rothstein, "THE BIG BANG: It sure was BIG!!".
Mather, John C., and John Boslough 1996, The very first light: the true inside story of the scientific journey back to the dawn of the universe. ISBN 0-465-01575-1 p.300
Shestople, Paul, ""Big Bang Primer".
Singh, Simon, Big Bang: The most important scientific discovery of all time and why you need to know about it, Fourth Estate (2004). A historical review of the Big Bang. Sample text and reviews can be found at [4].
Wright, Edward L., "Brief History of the universe".
Feuerbacher, Björn and Ryan Scranton (2006). "Evidence for the Big Bang", FAQ at talkorigins.org.
"Proof of Big Bang Seen by Space Probe, Scientists Say" — National Geographic News
The Sabanci University School of Languages Podcasts: Origin of Elements by Alpay Taralp.
Scientific American Magazine (March 2005 Issue) Misconceptions about the Big Bang
Scientific American Magazine (May 2006 Issue) The First Few Microseconds
R. A. Alpher and R. Herman, "Reflections on early work on 'big bang' cosmology" Physics Today Aug 1988 24–34. A review article.

[edit] Religion and philosophy
Leeming, David Adams, and Margaret Adams Leeming, A Dictionary of Creation Myths. Oxford University Press (1995), ISBN 0-19-510275-4.
Pius XII (1952), "Modern Science and the Existence of God," The Catholic Mind 49:182–192.
Ahmad, Mirza Tahir, Revelation, Rationality, Knowledge & Truth Islam International Publications Ltd (1987), ISBN 1-85-372640-0. The Quran and Cosmology
[edit] Research articles
Most scientific papers about cosmology are initially released as preprints on arxiv.org. They are generally technical, but sometimes have introductions in plain English. The most relevant archives, which cover experiment and theory, are the astrophysics archive, where papers closely grounded in observations are released, and the general relativity and quantum cosmology archive, which covers more speculative ground. Papers of interest to cosmologists also frequently appear on the high energy phenomenology and high energy theory archives.


Retrieved from "http://en.wikipedia.org/wiki/Big_Bang"
Categories: Physical cosmology | Articles with unsourced statements | Astrophysics | Theories

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I hope this helps =)

Answer 2

Noone...absolutely noone knows the answer to this question.


It was probably something incredibly simple though.


It probably involved naturally what existed then, so you would want to consider energy, it's density and form, and the quantum mechanics that were governing it.

But that is only what we know. There could be numerous other factors involved.


But as you can imagine, if you have a lot of energy already there (Thermodynamics: Energy cannot be created or destroyed), then you already have the foundation for the universe. You just need a trigger.


Some have considered quantum mechanics and look at quantum fluctuations in energy. A random and large fluctuation could, if the energy was dense enough, cause the big bang. This is definitely a very plausable answer to the question, as it involves things we know existed at that time, and there is nothing impossible or outside of our knowledge about it. It would also explain why the things necessary for the universe to exist are so fine tuned, because there could have been any number of attempts at the universe before a fluctuation just right occured and the dominos started toppling.


Some have looked towards string theory to explain the beginning. It is complicated, but in basic terms, essentially two super energetic and unimaginably large string membranes, composed of the smallest thing possible, a string, ended up smashing into eachother, releasing an astronomical amount of energy.


There are also various other ideas surrounding the topic.





However, as a side note, it is now known that the universe does not big bang and then collapse and big bang again; current WMAP observations have confirmed that the universe is going to expand indefinitely and never collapse back onto itself.

Answer 3

The early Universe, prior to a million years after the Big Bang, is fairly simple---it was a nearly uniform collection of particles. It is clear that that collection of particles was expanding and cooling from some initial state (the Big Bang). Given what we know about gasses, plasma, and particles (from laboratory experiments), it is possible to "run the movie backwards" and follow the physics back in time to about a nanosecond after the Big Bang. At that point, the plasma is so hot, and so dense, that our theories of physics fail---it is simply not possible to extrapolate to such high temperatures and densities. In part, this is because we still have no theory that combines gravity with quantum mechanics, and it is clear that when things get too dense, this must be done. So modern physics gets us back within a very short time after the Big Bang, and then clearly fails.

This is not necessarily a permanent situation. If and when we have a complete theory of all the physical forces, it may be possible to understand things even earlier than the Big Bang. There are some hints in current physics---it is thought that a vaccuum, filled with all the quantum fields we know about, in an inflating gravitational geometry (like our current Universe), will occasionally give rise to a Big Bang, once in a long, long time (more than a google years), as a result of quantuum fluctuations.

On reason to reject "oscillating Universe" theories is that probably, there is no net creation of matter and energy in the Big Bang. The amount of positive energy stuff (all the particles and photons, etc.) could be cancelled by negative energy (gravitational potential energy), so the total amount of stuff in the Universe could be zero, in some sense. The creation of the Universe is not a matter of creating energy, so much as the separation of positive and negative energy. (Since neither positive nor negative energy has moral resonance, this should not be interpreted in Manichean terms.)

Why there is something rather than nothing is, however, a very deep philosophical/religious problem that has no good answer in science.

Answer 4

This question will be a little long.

Stephen Hawking would have you believe that the Universe had no beginning before the big bang. This is because his belief is that the Universe would have infinite density and time would be stopped. Because time is stopped, there is no reason to question as to the past before the big bang. This makes sense until you ask him what exactly inspired the big bang to suddenly decide to explode after an eternity of sit-still.
This caused stephen hawking to reconsider, and he instead (at least with black holes) considers an infinitely dense point to be impossible. I have yet to see his revised theory of the Universe, but other theories say that the universe has always been here. And it is in a constant big bang then contractionary cycle called the big crunch. This would lead to a cycle of "universe life times", and therefore a possibility for our rexistance, as well as our prior existences. The theory goes beyond this, but who knows...

Also, some people believe the big crunch may not happen anymore due to mathematical limits...but that is still debatable.

So in answer, it may have already been here, although, if the big crunch never happens...it would seem that the beginning is well...unexplainable.

I personally believe that the Universe is an infinite phenomenon of constant big bang, big crunches...but thats just me.

Answer 5

This isn’t a scientific argument, but rather a philosophical one which is completely beside the point. However, since I see it used frequently, I’ll go ahead and address it.

The Big Bang, like all science, doesn’t have any implications either for or against God. What it may do, it place constraints on how God did things and these may run contrary to scripture. However, there’s two important questions here:

First off, is the scripture right in the first place? And, second, assuming it is, are you interpreting it correctly?

The first one is really beside the point given that it would be folly to approach such a topic, but the second is worth addressing. Many Christians have absolutely no problem interpreting scripture in a manner that’s completely compatible with scientific observations like the Big Bang and Evolution. In regards to the Big Bang, many people choose to interpret the “7 days” as a rather metaphorical statement in which days are better understood as “phases” and could have, in reality, been billions of years. Such people also note that Genesis’ account (roughly) follows the order in which science says things happened (although the order does differ on some points).

I think it’s also important to note that the Catholic Church has affirmed the Big Bang and finds no problem reconciling the theological and scientific perspectives on this point. Both Pope John Paul II and the Vatican’s official astronomer, George Coyne, have given strong support for the Big Bang theory. Additionally, the theory itself was originated by a Belgian priest named Georges Lemaître.

So we see, the Big Bang can fit well with scripture so long as one is willing to look at things from the right point of view.

Answer 6

What about an answer like god created the big bang, which is what i believe. Im a christian and a scientist. I have looked at both sides of the discussion and found that there is enough evidence to support both sides and that 1 can coexist with the other.

Answer 7

There is no scientific answer.

The closest thing that I know of is an idea thrown out there by M-Theory, which is also known as String Theory or Super String Theory, which were older versions.

M-Theory is not scientific. There is no way to test it. But maybe one day there will be. The idea that I am talking about is something called branes. There are a lot of these branes and when they collide, some sort of shock wave moves inside of the brane which is what we would call the "Big Bang." There would be many of these going on and many universes would be created as a result, many of which may have wildly different physics, such as different laws of physics, different constants such as the speed of light, etc..

Answer 8

The best theory I know of so far involves the interaction of two other universes at the super string level (branes). This caused the Big Bang.
It makes sense if you study advanced quantum physics for many years, don't sleep, take a lot of caffeine, and hang around people who have IQs of 150+ and are borderline schizophrenic.

Answer 9

I think I was there some guy got shot I cant remember the details and since there was a spectulation the galaxy's might move stuck it on that to cover up the story and to run some one else into the ground when every he hears the big bang theory.

Answer 10

there is no theory at present that explains the first cause. the big bang is just concluded to have occurred based upon evidence and results that are observable. your guess is as good as anyones.
I say that God got angry and blew up his previous mistakes in a fit of pigue

Answer 11

i don't have a issue with the possibility and probability in any respect. For years I even have believed interior the Bible and in evolution. The Bible is a non secular e book and explains issues with metaphors, symbols, and parables. understanding this helps clarify the introduction defined interior the Bible. The extra I discovered approximately scientific theories and findings, the extra I knew that it had to be genuine. i be attentive to the Bible to be a real e book (nonetheless through fact it is been interior the palms of adult adult males there is a few blunders in writing, conveying, or our very own know-how and that i knew that i could wait and spot with all that.) I even have tried to proceed to be teachable and open minded and truthful with all of it. Why could i think that the mainstream non secular are precise approximately scripture interpretation whilst the mainstream non secular are the very ones who did no longer sense Jesus fulfilled scripture. They felt that he replaced into this manner of threat to the generic religions that they could have him killed (as a decide to God, whom they did no longer be attentive to). in no way provided that for the duration of murdering him they have been pleasurable much extra scripture. only through fact many look to believe one way does not make it genuine.