Big Bang

  • What does Big bang theory mean?
  • The Big Bang is the evolutionary theory of the universe and the cosmological model widely accepted, advocating that the universe came to an extreme and hot spot about 13.8 billion years ago. This theory, originally proposed by the Russian cosmologist and mathematician Alexander Friedmann and the Belgian physicist pastor Georges Lemaître in the 1920s, was a starting point for the universe, and was widely accepted among scientists, especially physicists, as it was supported by various evidence.

 

  • The basic idea of ​​the theory is that the universe, which is still expanding, has widened from a hot and intense initial state at a certain time in the past. This assumption, which Georges Lemaître calls the “first atomic hypothesis,” is nowadays settled in the name of “big explosion theory“. The skeleton of the model is based on Einstein‘s general relativity theory, and the first Big Bang model was prepared by Alexander Friedmann. The model was later defended by George Gamow and his colleagues and developed by adding the first nucleosynthesis event.

 

  • After the discovery of Edwin Hubble‘s relative redshift in 1929 in the distant galaxies (the light of the galaxies), this observation was taken as evidence that far-reach galaxies and galaxy clusters had an “apparent velocity” relative to our position. The highest “visible speed” from these are the ones that are the most distant. Since the distance between the galaxy clusters is increasingly increasing, all of them must be in the past together. According to the Big Bang model, the universe was extremely hot and intense during this initial state before it was expanded. The results of the experiments with “particle accelerators” produced under conditions similar to those of the original state confirm the theory. However, these accelerators have been tested only in high energy systems in the laboratory environment so far. If the expansion of the universe is left aside, it is impossible for the Big Bang theory to provide any definitive explanation without first finding the moment of the first expansion. The abundance we now observe of the light elements of cosmosis overlaps with estimates of the formation of light elements in the nuclear processes of the first fast expansion and cooling periods of the universe in accordance with the results of the first nucleosynthesis accepted in the Big Bang theory (the proportion of hydrogen and helium in the atmosphere, In the first minute, the cooling universe should have allowed some nuclei to form hydrogen, helium and lithium formed in certain quantities).

 

  • The Big Bang was first used by British physicist Fred Hoyle in 1949 during a speech on a radio (BBC) program called “The Nature of the Wheel“. Hoyle is a scientist who has contributed to how some of the light elements can bring some heavy elements.

 

  • Most of the scientists, at the outset of the universe, used the terms “cosmic microwave background composition” or Georges Lemaître’s “Big Bang” in 1964/1965, which was considered proof of the hot and dense period of the universe, After the discovery of the pale light echoes, they were convinced.

 

  • Big Bang Theory
  • The Big Bang model is basically based on two arguments: Albert Einstein’s general relativity theory and cosmological principle. The general relativity theory explains precisely the gravitational interactions of all objects. The discovery of general relativity by Albert Einstein in 1915 is considered to be the beginning of the modern cosmology, which makes it possible to define the universe as a whole, such as a physical system, since the universe defines gradual evolution with general relativity.

 

  • At the same time, Einstein was the first person to use universal relativity in this way, suggesting a solution (“Einstein universe“) that emerged from general relativity in defining space as a whole. This model ensured that Einstein’s enthusiastic attempt at that time led to the emergence of a new concept: Cosmological principle. According to Cosmological Principle, human beings do not have a privileged position in the environment, the universe is homogeneous and isotrope. That is, the homogeneity of the universe in terms of space, regardless of the place and direction where the person looks; More precisely, the general appearance of the universe does not depend on the position of the observer and the way he looks. This was a very audacious hypothesis for that period; Because no convincing observation at that time, the debate over whether or not there were any objects other than the Milky Way, later called the “Great Debate,” was unable to verify the existence of objects outside the Milky Way.

 

  • The “cosmological principle” implies that the universe is not bounded by the macro-properties of the universe, but that the Big Bang is realized in the space, not at a certain point, but also throughout the entire space. In the macro scale, the universe is homogeneous and isotrope. These two assumptions made it possible to calculate the universe’s later date from Planck’s time. Scientists are still trying to determine very important events that took place before the “Planck time“.

 

  • Einstein’s calculations of general relativity in 1915 revealed that the universe could not be stabilized. But at that time general acceptance was that the universe was static; So Einstein added the factor of “cosmological stability” to his equations to correct the end result. Thus, Einstein’s cosmological principle has added another hypothesis, which seems to have clearly diminished the level of validation nowadays; This was the hypothesis that the universe was static, that it evolved over time. This led him to change his initial solution by adding the term “cosmological constant” to his equations. But future developments will reveal that they are wrong. For example, in the 1920s, Edwin Hubble discovered that some “nebulous” galaxies today are out of our galaxy, and that they are moving away from our galaxy, and that their rate of departure is proportional to their distance to our galaxy (Hubble Law or Hubble Constant). Ever since this discovery, Einstein has found no evidence to substantiate the “static universe hypothesis”.

 

  • In fact, many physicists like Willem de Sitter, Georges Lemaître and Alexandre Friedmann had already found other “general relativity” solutions that defined a “universe expansion” before Hubble’s discovery. The models they have introduced

 

  • However, in the Big Bang hypothesis, the universe had a certain age that could be calculated from the path of expansion. The estimates of the expansion rate of the universe in the 1940s were rather exaggerated, which made the estimates about the age of the universe much less true. Thus, according to the values ​​reported by different dating methods that determine the age of the Earth, the Earth remained older than the earth. This was only one of the difficulties that preceded the Big Bang type models into various observations. But such difficulties are compounded by precisely determining the rate of expansion of the universe.

 

  • Observational evidence
  • Subsequently, two precise observational proofs fully entitled the Big Bang models: the discovery of the “cosmic microwave background composition“, which is the energy structure (the microwave domain) that can be called the remnant of the hot period of the universe history, and the measurement of the emission of light elements, ie hydrogen, helium, Measurement of the release of different isotopes of lithium.
  • These two observations took place in the early part of the second half of the 20th century and placed the Big Bang in the cosmology as a definitive model of the observable universe. This model almost perfectly overlaps with cosmological observations, as well as other evidences confirming the model: Galactic clusters’ observation and measurement of “cosmic background cooling” (measurement of current temperature difference a few billion years ago).

 

  • Cosmic background
  • Enlargement naturally tells us that the universe is more intense in the past. It seems that Georges Lemaître talked about the universe in the past for the first time in the past, But it has only begun to be investigated in real terms since the 1940s. The first thought came from George Gamow that the universe should be full of energetic loss by the expansion of the universe in a manner similar to the red sliding of astrophysical objects.
  • Gamow, in fact, realized that the strong intensities in the primitive phase must have allowed for the establishment of a thermal equilibrium between the atoms and then the presence of a constituent left by these atoms. Gamow developed Lemaître’s calculations in the 1940s and published a thesis based on the Big Bang. The Big Bang was supposed to have a certain remaining bounty left over. Besides, this glow was supposed to be all around the universe. It was supposed to be present at a density of the density of the universe, and therefore this density would have to be present even though it was now extremely diminished. Gamow, Ralph Alpher, and Robert C. Herman were the first to understand that the present temperature of this building can be calculated from the age of the universe, the intensity of the material, and the release of helium.

 

  • This is often referred to as the “cosmic microwave background (or cosmological microwave incremental) structure“, with the term “fossil radiation” nowadays. This radiation is in accordance with Gamow’s predictions, at a low temperature of a “dark body” (2,7 ° K). Arco Allan Penzias and Robert Woodrow Wilson owe this discovery to a somewhat coincidental endeavor: Arno Penzias and Robert Woodrow Wilson from the Bell Laboratories in New York in 1960 were trying to measure the vague radio waves coming from the outer parts of the Milky Way. But instead of this, a radiation coming from all over the sky is detected. This radiance or radiation was the same in all directions and it seemed to come from a medium of about 3 ° K. Interestingly, Penzias and Wilson, who had the Nobel Prize for Physics for these discoveries in 1978, were, like Fred Hoyle, to join the ranks of scientists who were opposed to the Big Bang theory.

 

  • The existence of a “blackbody” pithy can easily be explained in the context of the Big Bang model: In the past, the universe was exposed to heat and intense weariness. In this very high density universe of the past there was a wide variety of interactions between matter and radiation. The result is that the radiation is thermally, that is, the electromagnetic spectrum is the electromagnetic spectrum of a “black body”. On the other hand, the existence of such a constellation is almost unverifiable in the “steady-state theory” (although some advocates of the few point out the contradiction …)

 

  • The cosmic background, that is, the cosmic microwave background composition, at all, does not seem to be the greatest form of electromagnetic energy in the universe: about 96% of the energies are present in the form of photons in the cohesion, while the remaining 4% Visible spectrum “is due to the radiation of the stars and the cold gas in the galaxies (infrared). These other two sources are undoubtedly more energetic, but emit fewer photons. Presence of “cosmic background” in the “steady-state theory” is assumed to be a result of the thermalization of the starburst, presumed to be caused by the release of microscopic iron particles. But this model is contradictory to observational evidence. (Also, in this case, the “cosmic background” can not be described as a dark object.)

 

  • As a result, it can be said that the discovery of the cosmic background has historically been the definitive proof of the Big Bang.

 

  • First nucleosynthesis
  • From the discovery of strong nuclear power and the understanding that stars are the source of energy, the issue of clarifying the release of various chemical elements in the environment has emerged. During the 1950s, this release was being tried to be explained in two different ways – two different ideas of competition were proposed:

 

  • Stellar nucleosynthesis
  • Initial nucleosynthesis in the beginning
  • Supporters of the “steady-state theory” were constantly produced hydrogen during the course of time, and it was gradually turned into helium and then the heaviest elements in the heart of the stars. The helium or the division of the heavy elements maintained their continuity over time; Because the ratio of helium increased as a result of nucleosynthesis, and seemed to decrease proportionally with the occurrence of hydrogen. On the other hand, the Big Bang supporters believed that all the elements, from helium to uranium, were produced during the warm phase of the initial universe.

 

  • The current thesis is based on both hypotheses. Accordingly, helium and lithium were actually produced during the initial nucleosynthesis at the beginning. The main evidence for this comes from the examination of remote quasars for the release of the so-called light elements (hydrogen, helium, lithium). According to the Big Bang model, their relative oscillations are firmly attached to a single parameter that maintains its continuity since the first nucleosynthesis; Which is related to the density of the photons and the density of the baryons. With this single parameter, which can be measured by other methods, the release of the helium (He) isotopes and the lithium (Li) isotope can be explained. At the same time, an increase in the helium fraction is observed in the nearby galaxies, which can be regarded as a sign of the “interstellar medium” tidal evolution through the elements synthesized by the stars.

 

  • The evolution of galaxies
  • The Big Bang model assumes that the homogeneous universe has a more homogeneous structure than the present one in the past. Evidence is provided through observation of the radiating cosmic background. The cosmic background texture shows an extraordinary isotropy.

 

  • In this case, the astrophysical structures (galaxies, galaxy clusters) were not available in the first period of the Big Bang, and they should have gradually formed later. The process of the origin of the formations is known from the work of James Jeans in 1902; This process is known as Jeans Stability.

 

  • Now, according to the Big Bang model, the galaxies we have observed today were formed later, and these first galaxies in the past were not much like the neighboring galaxies we had observed nearby. With the speed of light being a great speed, with a certain speed, it is enough for us to look at distant celestial objects in the past to see what the universe looks like. For example, if we can not observe a celestial celestial a billion light years away from our planet, and we see that the celestial celestial one billion years ago came from the source of light coming to Earth, we can not see the state of that celestial one billion years ago.

 

  • According to the Hubble Act, observations of distant galaxies showing redshift characteristics show that the first galaxies are sufficiently different from those of the later galaxies. There were more interactions between galaxies at that time; Few giant galaxies have emerged after the unification of galaxies. In the same way, the class formations of spiral, elliptical and “irregular galaxies” have evolved over time.

 

  • All these observations concerning distant galaxies have been made with relatively rigorous studies; Because distant galaxies (due to their distances) are under-illuminated, so that they can be well observed require precise and perfect means of observation. The observations of the large “redshift” galaxies in 1990 by Hubble Space Telescope and later by large observatories such as VLT, Keck and Subaru provide us with the opportunity to verify the evolutionary phenomena of galaxy clusters as predicted by “models of galaxy formation and evolution.”

 

  • Examination of stars and galaxies in the first generation has become one of the main topics of astronomical research at the beginning of the 21st century.

 

  • Temperature measurement of the cosmic background in the large “red-shift”
  • In December 2000, Raghunathan Srianand, Patrick Petitjean and Cédric Ledoux succeeded in measuring the “cosmic background” heat of an “interstellar cloud” suit which they observed to be absorbed by the PKS 1232 + 0815 background quasar, which was found on the red rocks at 2.57 degrees.
  • Examination of spectral lines allows the understanding of the chemical composition of the cloud as well as the identification of the lines corresponding to the transitions between the various energy levels of the various atoms or ions present in the cloud. The chemical properties determined by a spectrometer (Very Large Telescope’s UVES spectrometer), which has a very high discriminating power for this cloud, made it possible for the first time to distinguish the heat of the “cosmic background”. Srianand, Petitjean and Ledoux found that the temperature of the cosmic background mix is ​​between 6 and 14 ° K (Kelvin); In other words, if the cloud was found to be red at 2,33771 degrees, it was in harmony with the Big Bang’s estimated 9.1 ° K.
  • His discoveries were published in Nature’s British scientific journal.

 

  • Big Bang’s chronology
  • The chronological stages of the Big Bang are tersten, that is to say, from past to present:
  • Today’s universe (+ 13.7 billion years)
  • Our universe is extremely low (now a few atoms per cubic meter per cubic meter) and cold (2.73 kelvin, ie -270 ° C) compared to what it is now. Although there are some very hot astrophysical objects (stars), the radiation that the universe is now exposed to is very weak. In this case, the share of the low frequency of stars in the world is great, so the distance between a star at any point of the universe and the star closest to it is extremely large. Astronomical observation teaches us that stars and galaxies are present very early in the history of the universe, before a billion years before the first Big Bang.

 

  • Merger
  • After 300,000 years from the Big Bang, the universe was a thousand times hotter and a billion times heavier than it is today, and stars and galaxies have not yet existed. A photograph of the first visible state of the universe 300,000 years after the big explosion, about 13.5 billion years earlier It was pulled. In 1992, this photograph of NASA’s COBE satellites seemed to be fully compatible with the calculations of astrophysicists. This is the period when the density of the universe falls to a level enough to allow the light to radiate. The main obstacle to the propagation of light earlier in the day was the presence of “free electrons”. During condensation, these “free electrons” came together in atomic nuclei to form atoms. Therefore, this turning is called the “merging period”.

 

  • It is also referred to as “the period of separation of matter and spirit” from the period when the light begins to spread at the same time. Here is the radiance we call the cosmic background, radiance or lights that have been able to daylight from this period. According to NASA’s WMAP compliance in 2006, a clearer map of the universe was made 380,000 years after the Big Bang. According to the results, 12% of the universe is from atoms, 15% from photons, 10% from neutrons and 63% In the light of the results, the beginning of 380,000 years after the Great Burst, since 12% of the universe is formed of atoms, the beginning of the first atoms must be 300,000 years from the beginning of the Big Bang when the free electrons can be emitted by arranging around the atomic nucleus .380,000 years can only be thought of as the time of the “merger period”. Also, since a map of the COBE satellite can be issued 300,000 years later from the Big Bang with the 1992 data, the beginning of the time when the light can be freely propagated in the environment requires 300,000 years. This is the indication that free-running electrons first began to line up around the nucleus of the atom at this time, in other words, when the first atoms began to form. Acceptance of axioms requires the acceptance of the invalidation of the COBE conforming data. Such a situation is not mentioned in NASA sources. As a result, the 380,000 year period has not taken place for 300,000 years, reflecting the situation that WMAP observes in order to produce a clearer map of the universe.

 

  • First nucleosynthesis (+ 3 min)
  • 300,000 years after the first period of the Big Bang, the universe consisted of a “plasma of electrons and atomic nuclei.” (This assumption of 380,000 years contrasts with the WMAP satellite’s 2006 data, as stated in the above paragraph, , The universe has been determined to be 12% larger than the Big Bang in 380,000 years.)

 

  • When the heat is high enough, atomic nuclei can not exist; In this case a mixture of protons, neutrons and electrons can be mentioned. Nucleons can be combined into atomic nuclei when the temperature falls below 0,1 MeV (Electron Volt, about one billion degrees) in conditions predominant in the initial state. However, in these conditions it is not possible to form atomic nuclei heavier than lithium. Hence, only the hydrogen, helium and lithium nuclei are formed in this phase, which starts about one second after the beginning of the Big Bang and lasts for about three minutes. This phase or period is therefore called the first nucleosynthesis. Nowadays, modern cosmology researchers are looking at an already completed subject for the first nucleosynthesis issue in terms of observing and understanding the results.

 

  • Destruction of electron-positron pairs
  • Universe heat exceeding 0.5 MeV (five billion degrees) just before the first nucleosynthesis that started when the temperature was 0,1 MeV (Electron Volt) was equivalent to the mass energy of the electrons. Beyond this temperature, the interactions between electrons and photons can spontaneously create electron-positron pairs. Although these pairs may disappear spontaneously, they will be recreated non-stop as the temperature exceeds the 0.5 MeV threshold. As the temperature rises below this threshold, almost all of these pairs disappear into photons with electron excesses arising from baryogenesis.

 

 

 

 

 

  • Separation of neutrinos
  • Just before this time, the heat was above 1 MeV (ten billion degrees), which is sufficient for various interactions of electrons, photons, and neutrons. From this heat these three species are in “thermal equilibrium“. When the universe cools, electrons and photons continue to interact, but their interaction ceases. This period is the period of separation of neutrinos. Therefore, there is a “neutrinolar cosmic background” that has characteristics similar to those of the “cosmic background” we know. The existence of the “cosmic background” of neutrinos, which play an indirect role, has been indirectly confirmed by the results of the first nucleosynthesis. The direct detection of the cosmic background of neutrinos has been extremely difficult with current technological possibilities, and there has been no debate about their existence.

 

  • Baryogenesis
  • Electromagnetic and weak nuclear power can be described as two different views of a single interaction, with different particles and fundamental interactions (elementary powers) of atomic particles and interactions being treated as only different aspects of the “elementary antitel” (neutron, proton, Particle physics is based on the general idea supported by experiments. More generally, the laws of physics and the universe are assumed to be more “symmetrical” at high temperatures.

 

  • For example, in the past, substances and antimatter are considered to be present as quantitative partners in the environment. Today’s observations show that antimatter is virtually non-existent in our observable universe.
  • In this case, the existence of the substance was at a certain time a slight excess of the substance compared to the antimatter (the antidote to the substance). During the next evolution of the universe, matter and antimatter disappeared in equal quantities, leaving the lightest substance behind them. This usual substance is made up of so-called baryons, the so-called streak baryogenesis of which the excess substance is formed.
  • Little is known about this stage or process. For example, the heat gradation that occurs during this event varies according to the Big Bang models (this is one of the differences between the different Big Bang models). The conditions for the baryogenesis to take place were called the “Sakharov conditions” because of the work of the Russian physicist Andréi Sakharov in 1967.
  • “Grand Unified”
  • The growing number of indications suggests that weak and strong electromagnetic forces are only one aspect of a single interaction (force). This is now generally covered by the “Grand Unified Theory” (Grand Unified Theory), also known as the GUT, abbreviated in English. It is believed that this interaction or force is manifested in the heat above 1016 GeV (1029 degrees). Presumably, then, the universe must have undergone a phase in which GUT theory finds application. Although the nature was not yet known, this phase should have taken place at the origin of baryogenesis and possibly the dark matter.
  • Cosmic swelling
  • Big Bang theory has brought new issues to cosmology. For example, it suggested that the universe was homogeneous and isotropic, but did not explain why it should be. In the simple version of the theory, however, there was no mention of a mechanism or functioning in the realization of the Big Bang, which leads to homogeneity in the environment. Thus, it was assumed that the cause or reason of swelling (first sudden, rapid expansion) initiated a process leading to homogeneous and isotropic universe.
  • The conclusion of the concept of “cosmic swelling” is that Alan Guth, who first proposed a scenario-defining scenario. François Englert and Alexei Starobinsky are also known as other names in the same period (1980) who worked on some problematic parts of this subject. Guth later (in 1982) found that, in some studies, cosmic swelling involving the seeds of large astrophysical structures, according to the results of these studies, not only allowed the universe to explain homogeneity, but also explains why the universe should contain some contradictions to homogeneity.

 

  • The history of the universe must have taken place in the very hot (between 1014 and 1019 GeV, ie between 1027 and 1032 degrees) early and adjacent to the Great Union and Planck Age. The fact that almost all of the issues revealed by the Big Bang theory can be explained by the inflation process and the fact that other scenarios are explained inadequately despite the fact that the other scenarios are more complicated have provided a more preliminary plan for the cosmology. From the detailed observation of the anisotropes of the cosmic background, it became clear that the inflatable models did not need to be reinforced with evidence, since they were quite confident. The adaptation of the inflatable scenario to the observations has allowed him to be placed in the main role in all matters related to the subject.

 

  • The inflationary universe expands very quickly over a period of time. This universe, which has become less dense due to its expansion, was filled with a very homogenous energy species. This energy then transforms into particles that will interact and become warmed up very quickly. These two stages, which end up swelling, are called the “pre-warming phase” in terms of the explosive creation of the particles and the “warming phase” in terms of the thermalization of the particles. The general operation of the swimmer has been well understood, but its functioning before and during the warm-up phase has not been fully understood and is still subject to various researches.

 

  • Planck Age – Quantum Cosmology
  • Beyond the swelling phase (before), more generally, in temperatures such as Planck’s heat, a field is entered into which the current physics theories are no longer valid. This is a concept in which the concept of quantum mechanics applies, where a correction in general relativity theory will be the subject. A quantum gravitational theory that will arise from the twist theory of development, perhaps as yet unspoken, will allow the various speculations about the Planck Age period to be included. Many writers, such as Stephen Hawking, have proposed various ways of research that will enable them to define the universe in these periods. This research area is now called quantum cosmology.

 

  • Cosmology standard model
  • The “cosmology standard model” is the logical result of the proposed Big Bang vision in the first half of the 20th century. The “cosmology standard model,” created by sampling from the standard model of the nominal particle physics, provides a definition of a universe that matches the unity of universal observations.
  • In particular, he stipulates the following two points:
  • The observable universe is born with an intense and warm evredence (Big Bang). A mechanism at this stage ensures that the region we can access (we can observe) is homogeneous, but at the same time it shows some exceptions. Although there are other proposed functions, this is probably a swollen type operation.
  • The current universe is filled with many kinds of matter:
  • Photons, which represent all kinds of electromagnetics.
  • Neutritional.
  • The baryonic substance that makes up the atoms.
  • The so-called dark matter is one or more matter types that are more massive than the stars that make up themselves, responsible for the structure of the galaxies, which can not be produced in the laboratory environment but are predicted in particle physics.

 

  • An energy type with unusual characteristics called dark energy, responsible for the “acceleration of the expansion of the universe” observed today (and probably not directly related to cosmic swelling).
  • Now, most of the astronomical observations make use of these indispensable foundation stones in defining the universe we know. Cosmological research was mainly intended to define the types of these substances, their properties, and the accelerated expansion scenario of the primitive universe. The three pillars of the “cosmology standard model” require resorting to unobserved physical phenomena in the laboratory environment: cosmic swelling, dark matter and dark energy. There is no satisfactory cosmological model that ignores these basic stones or any of them.

 

  • Features, results, issues and solutions
  • Big Bang’s issues
  • When the Big Bang models were examined, it was seen that this type of model brought some problems together. Before the changes were made, the simple Big Bang model did not seem to be a convincing model; Because it required the assumption of many physical quantities in extremely large and extremely small quantities compared to conventional quantities.

 

  • In other words, it seemed to require many parameters to be added to unexpected values ​​in order to survive. This type of “fine tuning” in the universe is considered problematic in all physics models with or without cosmology. In this case, despite the success of the many witness statements, the Big Bang fell into a concept that posed many problems but could not solve them, and therefore the solution it brought was not very attractive.
  • But the scenarios added to the Big Bang models, especially the cosmic infliction scenario, have changed the negative comments made in the first time theory.

 

  • Horizon issue
  • If the aesthetic and simplicity arguments are excluded, there is no reasonable reason why nature prefers that the universe be homogeneous and isotropic. There was also no satisfactory operation in the first Big Bang model, explaining why homogeneity is the anisotropy of the cosmic background composition and some of the deviations responsible for the formation of large structures in the state (galaxies, galaxy clusters, etc.).
  • It was a matter of no satisfactory explanation, and it was tried to be solved for a long time with the process explanations that led to the problem, that is, the universe evolved from the initial conditions that we have evolved into what we have observed in our day (homogeneous and isotropic). The problem can be expressed as follows: How could it be explained that, even if they were close to each other in the past, they did not have any time to exchange information, and that the two extremely distant regions of the universe had essentially the same characteristics? This issue is now called the “horizon issue”.

 

  • The issue of planarity of the universe
  • Another issue encountered when examining the evolution of the universe is the possible “radius of curvature” (the distance to the surface from a centimeter or an ellipsoid cismin center, where the curved surface consists of a curved surface and a radius can be obtained by completing the spherical object).
  • General relativity reveals that if the distribution of matter in homogeneity is homogeneous, then in this case the geometry of the universe depends on only one parameter, the so-called spatial curvature. Intuitively, it can be said that this quantization is related to a distance scale beyond the “Euclidean geometry”, which is no longer valid in the conditions of this kind.
  • For example, the sum of the interior angles of a giant triangle spreading a few billion light years away from its corners may not be equal to 180 degrees. Along with being unconfirmed, it is quite normal to encounter such cases when there are larger distances than the distances of the observable universe.

 

  • However, if the so-called “radius of curvature” tends to become smaller than the size of the observable universe, another issue arises. In other words, if the “radius of curvature” was larger than the size of the “observable universe” five billion years ago, it would have to be smaller than the size of the “observable universe” today, and the effect or consequences it had to be made visible. As we continue with this reasoning, it can be said that the radius of curvature is much larger than the size of the observable universe during the nucleosynthesis period, as the effect or consequence of the curvature is not apparent. The fact that the radius of curvature remains larger than the radius of the observable universe is now called the flatness problem.

 

  • The issue of monopolies
  • Particle physics predicts that new particles gradually appear during the cooling of the universe.
  • Some of them should have appeared during the so-called state change, which is supposed to take place in the primitive phase. Some of these particles, called coaxial or magnetic coaxial, have the ability to be stable and numerous and extremely heavy (one of the typical features of the proton being 1015-fold). If such particles had descended, their contribution to the density of the universe had to be high at a considerable rate as compared to the ordinary madden.
  • However, even though the universe owes some of its intensity to the kinds of substances we do not know, there is absolutely no room for particles with an exceptional amount of space, such as those of the monoclays. With the particle physics foresee, such heavy particles, which can not be determined whether they really existed from what they could not be discovered, are called the question of monocotyledons.

 

  • The formation of constructions
  • Observations show that the universe is homogeneous on a large scale, but at the same time it shows that it includes deviations from homogeneity on small scales (planets, stars, galaxies, etc.), that is, it also has the property of being not homogeneous.
  • Nowadays, it is known and can be explained how, when certain conditions arise, how the small homogeneity of the distribution of matter grows up to create a more intense and important astrophysical body from its surroundings. This is called Jeans Stability operation. However, in order for such a process to take place, it must first be assumed that there is a small non-homogeneity, and it also shows the diversity of observed astrophysical structures that the distribution of these non-homogeneous states, in which the initiator is active, in terms of width and size is a precise period known as the “Harrison-Zel’dovich spectrum” It is the subject. The first Big Bang models were insufficient to account for such turmoil or indecisiveness. So when the first Big Bang models were introduced, the issue of the formation of structures emerged.

 

  • Suggested solutions
  • About the horizon issue
  • The question of horizon and planeism can be taken as the root of the same issue. As time progresses, the enlargement continues and larger regions containing more and more matter are passed. It is astonishing that galaxies that have increased in number as time progresses have the same characteristics.
  • A solution to this question is that in the early days of the universe history, a particular information about the state of the universe was spreading very quickly to the whole house. In such a case, the universe may have exchanged information that would allow them to enter into very similar regions with very distant regions. The obstacle to this solution is special theory of relativity; Special relativity theory stipulates that nothing can move faster than light.
  • Nevertheless, although the expansion of the universe has been very rapid, the limits of specific relativity may have been somehow overcome. In fact, in such a case, while the size of the observable universe remains constant, the distance between the two regions of the universe may increase exponentially. In other words, a very small and homogeneous region at the beginning has a very large size compared to the observable universe region. When this phase with a constant expansion rate is completed, the homogeneous region of the universe we find can be significantly larger than we could have seen.
  • Friedmann’s equations show that such scenarios may be possible, provided that the presence of a substance that is not typical in the environment is accepted.

 

  • About the issue of planarity
  • The issue of planarity can be solved in the same way. The question is “the radius of curvature“, which grows less rapidly than the size of the observable universe. However, if the law governing the expansion is different from the law that governs the expansion of a universe filled with ordinary material, this can no longer be true.
  • Assuming the presence of a material trace with non-typical properties (eg, pressure-negative), the “radius of curvature” will grow faster than the size of the observable universe. It is not surprising that such an expansion phase has been in the past and that the radius of curvature can not be measured if it has been long enough.

 

  • About the unipolar issue
  • The issue of magnetic synapses can be solved by an accelerated expansion phase. This is the tendency to reduce the intensity of all the usual matter in the environment. But a new issue arises in this case: the accelerated expansion phase, leaving a homogeneous, but materialless universe in a bubble-free spatial plane behind.
  • The “cosmic swelling” scenario proposed by Alan Guth in the early 1980s has been a solution to all of these problems. In this solution, it is the “non-typical substance” type that has all the necessary properties that cause the rapid expansion. In the solution, the “scalar field” responsible for this expansion, which becomes unstable as a result of the rapid expansion, is gradually broken down into “standard model” particles during the complex processes called “preheating” and “warming“.
  • Although the first model of cosmic swelling presented various technical problems, the following recommended models were developed to be reasonable, free from these technical problems. An alternative solution to the cosmic swelling solution of the monotonic, flatness and horizon subjects is presented by the Weyl curvature hypothesis.

 

  • About the formation of large structures
  • In cosmic bulging, the material has quantum fluctuations or fluctuations (as a consequence of Heisenberg’s uncertainty principle) of every species. One of the unexpected consequences of the swimmer evolved to become the usual classical intensities during the “accelerated expansion phase” of these fluctuations of quantum nature at the beginning. The spectral calculations carried out within the scope of these “cosmological disturbance theories” revealed that these fluctuations were followed by the “Harrison-Zeldovitch spectrum” prints.
  • Cosmic swelling thus allows us to explain the emergence of small escapes or deviations from homogeneity in the environment. The unexpected success of the first cosmic swelling model led to the preparation of a later developed version: According to this model, the details of the small homogeneous states created during the cosmic swelling could be the first reasons for the non-homogeneity in our current universe. The coherence between these estimates and the observations made by examining the data related to the “cosmic background fluctuations” observed in the COBE and WMAP satellites is of an interesting level. This adaptation, which is seen in the results of the “galaxies catalog” prepared by SDSS (Sloan Digital Sky Survey) team, Reveals one of the great achievements of cosmology.

 

  • Dark matter
  • Various observations made in the 1970s and 1980s have proved that there is not enough visible matter to explain the apparent effect of gravitational forces between galaxies and galaxies. This finding naturally resulted in the fact that up to 90% of the substance in the environment was formed from a substance that does not emit light or interacts with the normal baryonic substance (dark matter).
  • The dark matter is a type of matter that does not emit light or reflects sufficiently in such a way that the electromagnetic rays can be directly perceived.
  • Although the existence of the dark matter has initially been a controversial issue, various observations, especially those of the following observations, have revealed the existence of anisotropies in the cosmic microwave background composition, velocity losses in galaxy clusters, broad distribution of structures, and X- rays measurements in galaxy clusters.
  • While no dark matter is produced in the laboratory environment, evidence of the presence of dark matter is particularly gravitationally influenced by other substances. Until now, many particles that could be particles of dark matter have been presented as candidates for science circles, and many projects have been launched to uncover or discover dark matter particles.

 

  • Dark energy
  • Measurements of the “redshift” – “apparent magnitude” relationship in Ia type supernovae have shown that the expansion of the universe has accelerated since it reached the present age of the universe. In explaining this acceleration, “general relativity” required that a part of the energy in the state consisted of an element with a large negative pressure, which is called “dark energy” nowadays. The presence of dark energy is understood in other ways as well.
  • Negative pressure is a type of vacuum energy. But the true nature of dark energy can be said to be the remnant of one of the great secrets of the Big Bang. For some it is a cosmological ore or a saboot.
  • The result of combining the data of the WMAP (Wilkinson Microwave Anisotropy Probe) WMAP team of 2008 with the data of the “cosmic microwave background composition” and the data of other sources shows that 72% of the present universe is darker, 23% is darker, 4.6% is regular ) Material and less than 1% of the material is neutrino.
  • The density of the dark energy remains constant, although the intensity of energy in the matter decreases with the expansion of the universe. As a result, even if the substance has formed a significant part of the entire energy of the universe in the past and still constitutes a considerable part of it, in the distant future the contribution to the universe will fall well and the dark energy will become even more dominant.
  • In the current best Big Bang model, ΛCDM, dark energy is explained by the existence of a cosmological constant in general relativity theory. However, the size of the fixture, which explains the dark energy well, is surprisingly small when it comes to estimates based on ideas of quantum gravity. The distinction between cosmological persistence and other dark energy explanations is currently an area of ​​research, an active field of study that is the subject of ongoing research.

 

  • Different cosmological models that accept cosmic swelling
  • It is a false belief that the Big Bang is based on the beginning or the beginning of the history of the universe. The Big Bang shows only that the universe has passed through an intense and hot period. There are various cosmological models that describe this intense and warm stage in a very different way.
  • One of the first models presented was Georges Lemaître, assuming that the density of the material was a density of nuclear material (1015 g / cm3). Lemaître rightly believed that it was difficult to find the precise knowledge of the behavior of such material at such concentrations, and assumed that the thing that initiated the expansion was the disruption of this unstable giant atomic nucleus. The Lemaître noted earlier that in 1931 the universe always had to resort to quantum mechanics in defining the first moments of history, and probably lost the usual qualities of space (space) and time concepts.
  • Different models have been created that deal with cosmic swelling and Big Bang with a different point of view, completing the inadequate points of classical Big Bang models today. Some models of cosmic inflation assume an infinite (infinite) universe, some models, such as the pre-Big Bang, assume that the first is not very intense, but then they have a recoil phase, and some models based on string theory are beyond the four dimensions of the observable universe Assuming it is immersed in a distance. According to these last models, the Big Bang and the expansion movement stem from the collision between the two brane. Some models also compare the motion of the universe to a repeated pulse (expansion and contraction).
  • As a result, we must repeat that the universe we observed is born of the Big Bang. According to the Big Bang theory, the elemental particles that we know today are formed in the intense and hot period, and all the structures observed in the process are formed in the subsequent processes.

 

  • What is the Big Bang?
  • The conditions that prevailed in the observable universe in the first period of the Big Bang were the same everywhere. On the other hand, it seems that the material elements have rapidly moved away from each other due to the expansion of the universe. The Big Banging term has been proposed as a term to express the severity of this enlargement movement.
  • There is no central or special aspect of the Big Bang. How the universe is in the past, but the distant regions of the universe can be understood by observing. The farther a region can be observed in the background, the more distant a history can be found in the history of the universe. But what can be observed nowadays is not directly the first period of the Big Bang itself, but the “cosmic background composition” which is the luminous reflection of this hot stratum in the history of the universe. This radiation is mainly uniform and can be observed in every direction. This suggests that the Big Bang has grown in an extremely homogeneous fashion in areas with observable possibilities. The reason why the Big Bang’s first state can not be determined is because the primary universe is dull due to its high density.
  • Contrary to popular belief, the Big Bang is not an explosion anywhere. The Big Bang or the Big Bang is not an explosion at any point, as it might have been the first to hear someone’s name, throwing out the substance that makes up the galaxies of our day.

 

  • Philosophical results
  • The solution proposed by the Big Bang, or at least in its simplest model, was deemed appropriate by some philosophers. According to these philosophers, the basic idea was developed on the basis of Creationism’s suggestion of the “Initial Universe”. While the science mosque looked at the theory with suspicion, the masses of the general public in a short time accepted it as the confirmation of Creationism. In addition to the earlier interpretations of the beginning of the universe in theology and philosophy, this scientific development led to the confirmation or questioning of previous movements by different commentators in the fields of philosophy and theology. This is Papa XII. Especially expressed by Pius.
  • According to some, the chronology proposed by the Big Bang possessed the contrary appearance of the opinion of the founders of attraction theories such as Newton, Einstein, who believed that Creation was infinite. The Lemaître had a different point of view than the Pope had expressed. On the other hand, although it is not based on scientifically acceptable evidence, it has been argued that Lemaître’s religious convictions helped prepare the Big Bang model.
  • Some scientists have expressed that astrology and cosmology data do not overlap with any philosophy or theology.
  • In contrast, some astrophysicists have argued that the subject could be associated with God’s presence. The US astrophysicist Hugh Ross, for example,
  • “Since time is the dimension to which events take place, if matter emerges with the Big Bang, then the reason that unveils the universe must be totally independent of the time and space in the world, which shows us that the Creator is above all dimensions in the world.”

 

  • Critics from scientists
  • One of those who reject the Big Bang theory and think that theory is the criticism to be criticized is Fred Hoyle, the architect of the “steady-state theory“. The following names can be given as examples from the standpoint of theoretic world:
  • Hannes Alfvén (1908-1995): Nobel Prize for Physics was awarded in 1970 for his work in the plasma physics. He has completely rejected the Big Bang. Defend the theory of the “plasma universe” as its theory.
  • Edward Arthur Murne (1896-1950): Newtonian cosmologist, advocating that expansion is nothing but a galaxy motion in a static phase.
  • Arno Allan Penzias and Robert Woodrow Wilson: In 1968 they won the Nobel Prize for Physics in 1978 for their discovery of cosmological thermals. Their discoveries were later called the cosmic microwave background composition.

 

  • Despite undeniable successes, the Big Bang still opposes some of the world of science today. There are also some astronomers on the front of this opposition. An example of this opposition is Geoffrey Burbidge, Fred Hoyle, and Jayant Narlikar, who have developed a new “steady state” version based on the creation of the material.
  • A recent critique of the Big Bang is the discrepancy between the age of some distant cosmic bodies, such as the Abell 1835 IR1916 and the HUDF-JD2 galaxies, and the age of the universe that is younger. But often such problems come from bad age estimates.

 

  • Current status
  • Big Bang theory is based on two basic ideas: the universality of physical laws and the cosmological principle. Cosmological principle, as mentioned before, assumes that the universe is homogeneous and isotropic on macro scales. These ideas were hypotheses, but nowadays they are supported by observations.
  • Observational developments in observational cosmology provide the Big Bang with definite support, at least among researchers working in this area. The “steady state theory”, the basic theory opposite the Big Bang, is now completely marginal, due to its observations of the cosmic background composition, the release of light elements, and the inability to account for the evolution of galaxies.
  • The Big Bang is, in fact, the result of general relativity, which can not make a mistake of observations. Therefore, according to some people, rejecting the Big Bang means rejecting general relativity.
  • However, it is a fact that many periods or phenomena are still not well known. For example, the details of the baryogenesis period and the end of the cosmic swelling phase, especially the pre-warm-up and warm-up phases, in which a slight surplus of substance compared to antimatter is mentioned … With the developments of the Big Bang models to be developed, now the general concept of the Big Bang It is hard enough to argue.

 

 

  • According to the Big Bang theory
  • Before understanding the existence of dark energy, cosmologists developed two scenarios about the future of the universe. If the “mass density” of the universe is greater than the “critical density”, the universe will enter the decay process after reaching its maximum dimension. It will be more intense and warmer, and this process will complete with a situation similar to the one at the beginning called “Big Crunch“.
  • As an alternative to this scenario, if the density in the environment is equal to or below “critical density“, the expansion will slow down but never stop. The star formation in the stars will stop in all the galaxies, the stars will turn into white dwarfs, neutron stars and black holes. The collisions between them gradually led to the formation of mass accumulations, that is, the formation of massive bodies and the gradual enlargement of black holes. The average temperature of the universe will approach the “absolute zero” (the thermal death of the universe) as soon as possible. In addition, if the proton remains unstable, the baryonic substance will disappear leaving only radiant and black holes behind. Eventually the black holes would evaporate (disappear) by emitting “Hawking radiation”. Thus the entropy of the universe will climb to a place called the “thermal death of the universe” where no organizing energy can save itself.

 

  • Modern “rapid expansion” observations suggest that today’s “visible universe” will slowly slip past the “event horizon” mausoleum and out of our contact possibilities. The next situation or final result is unknown. The most advanced Big Bang model, the ΛCDM model, regards dark energy as a “cosmological constant” form. This theory or model assumes that only limited gravitational systems, such as galaxies, can coexist, so that they can not escape from the thermal death. Other explanations of dark energy, the so-called “phantom energy theories”, ultimately suggest that galaxy clusters, stars, planets, atoms, etc., will be separated by ever-expanding. It is called Big Rip.

 

  • Speculative physics beyond the Big Bang
  • With the Big Bang model settling in the cosmology, it is understood that the future should be more adequate in responding. Little is known about the earliest period of the universe. The Penrose-Hawking singularity theorems require the existence of a singularity at the beginning of the cosmic time. But these theorems assume that general relativity is always valid; Whereas the general relativity before the universe reaches Planck’s heat must not be valid and only a quantum gravitational behavior can be avoided from “singularity“.
  • In principle, the universe may be beyond the “observable universe.” This is quite possible if it is “cosmic swelling“; Because an expansive (which can be expressed with mathematical exponents) might have driven the great regions of space beyond our observation horizon.

 

  • Some suggestions that require untested hypotheses include:
  • Hartle-Hawking unlimited models: space-time is limited in these; Where the Big Bang represents the boundaries of time without the need for a singularity.
  • Brane cosmology models: cosmic swelling is caused by the movement of branes in string theory. These are the “pre-big bang model“, the “ekpirotic model” in which the Big Bang is regarded as the end result of the collision between two brane units, and the “cyclic model,” which assumes that the collisions specified in the ekpirotic model are repeated periodically.
  • Chaotic Inflation Theory: Cosmic inflation events in the chaotic inflation theory start everywhere within a random quantum gravity, creating separate universes with separate Big Bangs.
  • Models in the last two categories see the Big Bang as not a beginning of the universe, but a far larger, much older, multi-layered (or multi-dimensional)

 

Big Bang
Author: wik Date: 2:58 pm
Science and Mathematics


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