The Big Bang: The Birth of the Universe
The Big Bang theory is a model of cosmology put forward to explain the origin of the universe. According to this theory, the universe emerged as an explosion from a dense point (a super dense, super hot and super energetic point) about 13.8 billion years ago.
According to the Big Bang theory, at the beginning of the universe, all matter, energy, time and space were stuck at one point. This point is inexplicable in processes prior to Planck’s time. However, after Planck’s time, the universe began to expand. The density and temperature of the universe have decreased continuously.
The Big Bang explains the beginning of the universe, but it also gives information about how the universe expanded and developed. As the universe expands, it is thought that with the dispersion of matter, energy and light, the universe cooled and matter formation took place. First, the formation of the elements began, and then stars, galaxies and other celestial bodies took shape.
While the Big Bang theory explains the expansion and evolution of the universe, it is supported by evidence such as observations and cosmic background radiation. Cosmic background radiation is a trace of radiation from the Big Bang and provides information about the youth and homogeneity of the universe.
The Big Bang theory provides an important framework for the origin and evolution of the universe. However, some questions about the beginning of the universe still remain unanswered, and scientists are doing more research on this.
Origins of the Universe: Theories and Research
1-Big Bang:
The big bang is also among the origins of the universe and research, so it is the same as described above.
2-Inflation Theory:
Inflation theory is a model of cosmology put forward to explain a period of rapid expansion thought to have taken place in the early stages of the universe. This theory aims to solve some problems related to the homogeneity, smoothness and structural properties of the universe.
According to the inflation theory, an “inflation” took place in an extremely short period of time, about 10^-36 seconds, in the very early stages of the universe. This period of inflation allowed the universe to expand rapidly and reach a much larger size. This rapid expansion explains the smoothness and homogeneity of the universe.
One of the main reasons for the introduction of the inflation theory was that it was difficult to explain the observed properties such as smoothness and homogeneity in the universe with the standard cosmological model (Big Bang theory). Because at the beginning of the universe, a homogeneous distribution and a uniform temperature balance were not expected. Inflation theory proposed that a period of rapid expansion took place to solve this problem.
During the inflationary period, the expansion of the universe was so rapid that it was powered by a field energy called “enflaton”, which has a potentially infinite mass density. This field energy is considered a form of energy that has negative pressure. During the expansion of the universe, the energy of the inflation was transformed into kinetic energy, increasing the rate of expansion of the universe.
Inflation theory explains the large-scale uniformity, homogeneity, and structural features observed in the universe, as well as the distribution of cosmic microwave background radiation. This theory offers an additional mechanism to the Big Bang theory by providing a more detailed explanation of the expansion and structural formations of the universe.
However, the theory of inflation is still an issue that is being actively researched, and it brings with it some problems.
3-Circular Universe Theory:
The cyclical universe theory is a model of cosmology that proposes that the universe is in a constantly expanding and contracting cycle. This theory argues that the universe has no beginning and no end and is repeated in an endless cycle.
According to the cyclical universe theory, a phase begins with the expansion of the universe. This expansion causes the universe to expand and grow up to a certain point. Then, at some point, the expansion stops and the universe begins to contract backwards. The contraction process causes the universe to be compressed at one point back into a dense and hot spot. At this point, a new “Big Bang” takes place and the universe begins to expand again. This process repeats in an endless loop.
The cyclical universe theory offers a different approach to explaining the beginning and end of the universe. The cycle between expansion and contraction of the universe indicates a kind of continuous rebirth and regeneration in the universe. This theory proposes that the universe is in a continuous loop and thus has no beginning or end.
This theory provides the explanation of properties such as homogeneity and smoothness observed in the universe. It is thought that the structural problems of the universe can be eliminated with the corrective effects of previous expansion and contraction periods. However, the cyclical universe theory is still a topic under active research, and it raises some open problems.
The cyclical universe theory is a difficult subject to prove or disprove and still needs further research and observation. Studies continue on subjects such as how the expansion and contraction processes of the universe occur and how the distribution of energy and matter is affected. These studies aim to provide more understanding about the beginning and end of the universe.
4-Parallel Universes and Multiverse Theory:
Parallel universes and multiverse theory is a theory of cosmology that proposes that the universe consists of many universes rather than a single version. This theory argues that different universes exist and each universe has its own physical laws and conditions.
Parallel universes and multiverse theory offer an alternative explanation for the complexity of the universe and some fundamental physical problems. This theory proposes that many universes exist in parallel rather than a single universe in the universe. Each universe is considered a “universe” in its own right and has different physical properties.
This theory proposes that different universes exist and can interact with each other. These interactions can be based on factors such as differences in time and space, energy and matter distributions, or different physical constants. Each parallel universe functions as its own unique universe and obeys the physical laws of its own universe.
The multiverse theory relies on some observational and theoretical evidence pointing to the existence of parallel universes. For example, data such as the anisotropies of the cosmic microwave background radiation and the observed structural formations in the universe may support the existence of parallel universes. In addition, calculations in quantum mechanics and cosmological models are also based on multiverse theory.
However, parallel universes and multiverse theory is still an active area of research and is not supported by conclusive evidence. Some scientists argue that this theory faces challenges in terms of testability and verifiability. However, research and studies on this topic are ongoing and aim to provide greater understanding in the future.
5-Determining the Age of the Universe:
Cosmic Microwave Background Radiation: One of the most important pieces of evidence for determining the age of the universe is the cosmic microwave background radiation (CMB). CMB is the radiation that emerged as the universe cooled about 380,000 years after the Big Bang. The CMB traces the universe’s earliest moments and helps calculate the expansion and age of the universe.
By examining the distribution of CMB, it is observed that the radiation in the universe is distributed homogeneously and isotropically. By analyzing the fine details in this distribution, information about the age and structure of the universe can be obtained.
Hubble Constant and Redshift of Distant Galaxies: Another important method used to determine the age of the universe is the Hubble constant and the redshift of distant galaxies. The Hubble constant represents the rate at which the universe is expanding. The redshift in the spectra of distant galaxies is evidence of the expansion of the universe. The further away the galaxies are, the greater the redshift.
Backward calculations can be made using the Hubble constant and data on the redshift of distant galaxies. These calculations are used to estimate the rate of expansion of the universe and therefore its age.
Nucleosynthesis: Another method used to determine the age of the universe is a process called cosmic nucleosynthesis. Cosmic nucleosynthesis explains the formation of light elements in the early moments of the universe. In this process, the formation of basic elements such as hydrogen and helium takes place.
By observing the element ratios in the nucleosynthesis process and making calculations, estimates of the age of the universe can be made.
These methods and other cosmological models are used to determine the age of the universe. However, these estimates and calculations are based on certain assumptions and may contain some degree of uncertainty. Scientists are working to improve and confirm these predictions with more precise measurements and new observational data.
