Big Bang

The Big Bang theory is the prevailing cosmological model that describes the early development of the Universe. [1]

According to the theory, the Big Bang occurred approximately 13.77 billion yearsago, [2] which is thus considered the age of the universe. [3][4][5][6] After this time, the Universe was in an extremely hot and dense state and began expanding rapidly. After the initial expansion,the Universe cooled sufficiently to allow energy to be converted into various subatomic particles, including protons, neutrons, and electrons. Though simple atomic nuclei could have formed quickly,thousands of years were needed before the appearance of the first electrically neutral atoms. The first element produced was hydrogen, along with traces of helium and lithium. Giant clouds of theseprimordial elements later coalesced through gravity to form stars and galaxies, and the heavier elements were synthesized either within stars or during supernovae.

The Big Bang is a well-testedscientific theory and is widely accepted within the scientific community. It offers a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmicmicrowave background, large scale structure, and the Hubble diagram for Type Ia supernovae. [7] The core ideas of the Big Bang—the expansion, the early hot state, the formation of helium, and theformation of galaxies—are derived from these and other observations that are independent of any cosmological model. As the distance between galaxy clusters is increasing today, it is inferred thateverything was closer together in the past. This idea has been considered in detail back in time to extreme densities and temperatures, [8][9][10] and large particle accelerators have been built toexperiment in such conditions, resulting in further development of the model. On the other hand, these accelerators have limited capabilities to probe into such high energy regimes. There is little evidence...