Lead
"The term universe is actually a very big concept, and it includes both the Milky Way, the solar system, the Earth, and so on.
Of course, the universe also includes all the space between these planets and the various galaxies, so from this point of view, the universe is the sum of all the spaces we know. ”
But the concept of the universe is not limited to this, it also includes all matter and energy, as well as the sum of time and space, and even some things that we have not yet discovered.
The concept of the universe is so grand, so where did the origin of the universe come from?
The universe we live in today was born about 13.8 billion years ago, so what existed before the birth of the universe?
First, the Big Bang opened the world.
Von Maxwell once put forward the idea that matter and energy exist and that matter and energy can be converted into each other.
At the end of the 19th century, Einstein proposed the theory of mass-energy equivalence on this basis, believing that there is an equivalence relationship between mass and energy, and thus proposed the existence of protons.
On this basis, Einstein proposed the mass-energy equivalence relationship of E=mc^2.
According to this theory, protons can also be converted into each other under the right conditions.
However, this transformation process is extremely slow, resulting in the current universe, where protons do not transform.
But the situation was very different in the early universe, which had a very high temperature and a lot of energy.
In this environment, protons are transformed.
About 13.8 billion years ago, there was a "singularity" in the universe.
The singularity is a point with a lot of density and a lot of temperature, and at the same time there is a lot of energy.
The singularity at that time, which is that the energy of this point is very large and very dense, which makes a great gravitational pull generated.
At the same time, the temperature of the singularity is also very high, which leads to a nuclear reaction inside the singularity, which releases nuclear energy.
When the nuclear energy inside the singularity is depleted, the singularity explodes, releasing a large portion of its energy.
The vast majority of this energy is released in the form of photons, a process known as the "photon age".
After the photon age, the temperature in the universe decreases to a certain extent, and the energy inside the universe is no longer enough to produce new photons.
But the temperature of the interior of the universe remains, and this temperature is the temperature produced by the cosmic microwave background radiation.
As the universe expands and cools, the temperature is also decreasing, and the wavelength of microwave background radiation is also increasing, resulting in the frequency of microwave background radiation becoming smaller and smaller, and finally undetectable.
At the same time, the matter in the universe is also produced in this process, and the matter in the universe is also constantly evolving.
After the Big Bang, there was a large amount of energy in the universe, and this energy would continue to be released after the Big Bang until the energy inside the universe was exhausted.
2. Where does the singularity come from?
And the origin of the Big Bang is the singularity, so where did the singularity come from?
The singularity is a very big mystery, and in the 1960s, when Hawking was studying the singularity, he came up with a conjecture that the singularity was made up of a very small atomic nucleus.
This very small nucleus is constrained by a force called quantum mechanics.
Within this nucleus, there is a very high pressure, and at the same time, there is a very high temperature, which makes this nucleus explode, which leads to the creation of the singularity.
The size of this nucleus is very small, very small, much smaller than the volume of a proton, and there is also a very large density.
Traditionally, matter cannot exist at a very small point, but this nucleus exists at this very small point, which is different from what we usually know about matter, so this nucleus is called a singularity.
However, Hawking's conjecture has not been confirmed, as has the belief that the singularity was created by a high density of stars.
From a physical point of view, the origin of the universe was born from the singularity, and the Big Bang is the product of the singularity explosion.
But there is also an opinion that the origin of the universe did not arise from a singularity, but from a closed sphere.
In this closed sphere, there is a lot of energy, and at the same time, there is a lot of density, which makes this closed sphere have a lot of gravitational attraction and a high temperature.
This closed sphere would explode, resulting in a large explosion.
But this view has not been proven, and the idea that the Big Bang originated from the singularity is increasingly confirmed, so it is widely believed that the Big Bang is the origin of the universe.
3. The universe was born 13.8 billion years ago, so what existed before the birth of the universe?
So what existed before the birth of the universe?
This question has not yet been answered, so a new view has been put forward that the birth and destruction of the universe is a cyclical process.
In the process of this cycle, the universe will continue to be born and destroyed, and this process will continue to circulate, thus forming the cosmic cycle theory.
According to the cosmic cycle theory, after the birth of the universe, it will continue to expand, and at the same time, it will continue to cool until the internal energy is completely consumed.
After the internal energy is completely consumed, the universe will expand in reverse until it returns to the original state, and then it will continue to circulate, and this process is a cyclical process.
However, people do not agree with the cosmic cyclical theory, because the birth and destruction of the universe is a cyclical process, but the cosmic cyclic theory does not explain the birth of the singularity, that is, the cosmic cyclical theory does not explain the birth of the universe.
As a result, scientists have come up with a new view that the universe has always existed.
Time is a concept of human beings, it is a concept that describes the development and change of things, and the universe has no clear beginning and end.
From this point of view, the universe has always existed, and it has neither a clear beginning nor a clear end.
epilogue
Scientists still have a lot of work to do in exploring the origin of the universe, and people still only know the surface of the origin of the universe, and there are still many problems to be solved about the origin of the universe, so it is necessary for us to further explore and study the origin of the universe.