Western astronomers are almost unanimous that the universe was created by a massive explosion, known as the Big Bang theory, but are there alternatives? Have these theories, including the Big Bang theory, succeeded in explaining the origin of the universe?
The Big Bang theory was first developed about a century ago, and it briefly says that the universe began as a very hot and dense point that swelled over a period of about 13.8 billion years, becoming larger and colder.
Phys.org (phys.org) states that while this is not the only modern theory of how the universe originated, for example there is a stationary state theory or an oscillating universe theory, the Big Bang is the dominant theory so far.
This is because the Big Bang theory explains not only the origin of all known matter, the laws of physics, and the structure of the large-scale universe, but also the expansion of the universe, the formation of light elements, the presence of the cosmic microcosmic background and a wide range of other phenomena.
But this theory, in turn, still falls short of answering all questions about the universe and its origins, and has been criticized by many scientists.
Space presents some of the competing theories that have confronted the Big Bang theory for decades, and why it in turn failed to explain the origin of the universe, and began to talk about its properties such as that it expands, that it came out of a super-hot dense state and its lightest elements were created first, and that it has electromagnetic radiation called the "microcosmic background."
Eternal Universe Theory
Before the development of the Big Bang theory, scientists believed that from the beginning the universe was what it is today, and always will be. Although this theory talks about some ordinary things like stars exploding occasionally, in general it argues that it was a great cosmic fabric and remained unchanged and will remain so forever.
However, this theory waned and faded when the American astronomer Edwin Hubble discovered what is known as the phenomenon of the expansion of the universe. This discovery immediately overshadowed the idea of an eternal universe, because in an expanding universe the universe would be clearly different in the past than in the present and the future would be even more different.
The microcosmic background is one of the reasons why some theories fail to explain the origin of the universe (NASA)
Stacid-state model
The steady-state model, first proposed by British astronomer Fred Hoyle, is one of the theories that in the early twentieth century dealt with the subject of the universe, saying that it is always expanding, but there is always a new substance that appears in a vacuum to replace another.
Therefore, according to this theory, the universe increases but the density remains the same, so in the steady-state model, the universe is dynamic, but remains unchanged over long periods of time.
The steady state model has failed blatantly for two main reasons: quasars and CMB.
Pseudo-stars are galaxy nuclei that are very far from us, so only the core that appears as a star with a supermassive black hole in the middle. They are very bright sources of radio emissions found exclusively in the distant universe.
The microbackground of the universe is a source of radiation that surrounds us from all sides. The Big Bang theory tried to explain that light comes from an earlier era in cosmic history, but in the steady-state model, the early universe must look like the modern universe.
In the steady-state model the universe is always expanding but there is always new matter appearing in a vacuum to replace another (Wikipedia)
Electrical Universe
Another competitor to the Big Bang theory has emerged, thanks to Nobel Prize-winning physicist Hannes Alvin. who argued that something new should be replaced by the Big Bang. Electromagnetic forces were much stronger than gravitational forces, so what we observe in the universe should be better understood as consequences of electromagnetism rather than gravity. This included the evolution of the solar system, the birth of stars and the expansion of the universe.
Alvin explained the expansion of the universe and the microscopic background of the universe as consisting of large pockets of matter and antimatter, which are constantly competing. These bubbles stretch against each other, leading to what we consider to be an expansion of the universe and wherever they meet microwave background light is created.
Unfortunately for Alvin, there is no way for an electrical universe to match all observations in the universe, especially Hubble's law of expansion of the universe.
The universe in the blender
One feature that scientists have puzzled in explaining is what is known as the "horizon problem." The problem with the horizon, according to NASA's website, is that regions far from space in opposite directions from the sky, which have roughly the same temperature, are so far apart that it is unimaginable that they came from one place in the past.
This is because the travel time of light between them exceeds the age of the universe itself. However, the universe's uniform microcosmic background temperature tells us that these regions must have been in contact with each other in the past.
In 1969, physicist Charles Messner developed a solution to this problem, called Mixmaster cosmology. According to this theory, the early universe was incredibly chaotic, and this chaos led to two things, one "mixing" matter at small scales, which eventually gave rise to structures like galaxies, and the second equalizing things on large scales to make the universe as a whole homogeneous.
Mathematics never worked with the Mixmaster model, but another explanation that could solve the horizon problem in a much simpler way was "inflation."
The "inflation theory," according to NASA's website, is a period of extremely rapid expansion of the universe during its first few moments. Hence the universe expands relatively gradually throughout its history. This theory was developed around 1980 to explain many mysteries with the Big Bang theory.
The "oscillating" model of the universe means that the universe repeatedly forms itself in cycles (imggio)
The periodic model of the universe
This model, also known as the "oscillating" model of the universe, is a theory that the universe repeatedly shapes itself in cycles.
This theory is a reaction to the idea that the universe in the Big Bang theory had a starting point, meaning that there was a time without a universe. In contrast, there have been many attempts to come up with an explanation for the beginning of the universe, all of which end with the idea of replacing some kind of periodic universe with the Big Bang, where the explosion is just one of a long and unlimited series of universes.