Some people have seen the statement in the scientific community that the universe has been born for more than 13 billion years, and they always want to figure out what the universe looks like every time it is born. This curiosity is understandable, but the problem is that the scientific community cannot give a standard answer. Now we try to analyze this problem with some scientific common sense.
Singularity of the universe
The universe was born more than 13 billion years ago and is based on the Big Bang theory. Therefore, to know that the universe did not look like before it exploded 13 billion years ago, we must first recognize the Big Bang theory before we can trace it back based on this theory.
The Big Bang theory believes that the universe was formed by a singular explosion (or expansion) about 13.8 billion years ago. A singularity is an existence with infinitely small volume, infinitely high temperature, infinite density, and infinite curvature. From logical inference, we can see that the following three infinity are based on the first infinity, because the volume is infinitely small Things, as long as they have temperature, density, and curvature, can only be immeasurably large.
Since the Big Bang, the universe has been expanding. Now the universe has expanded to a diameter of 930 light-years in the observable universe. Matter is born from energy, from the earliest elementary particles to the current trillions of galaxies, and the expansion is still in progress. It is based on the observational facts of the expansion of the universe that the universe erupted from a singularity.
Classical physics believes that singularities cannot be recognized
Because there are no infinitely small things in our world, the smallest scale that humans can recognize is about 10^-35m. This scale is called the Planck scale, which is a scale that is one billion billion billion times smaller than an atom. The singularity is infinitely small, that is, it is not known how many times smaller than the Planck scale. Therefore, all the existing theories are invalid in that place. Therefore, humans cannot recognize the singularity, let alone the things before the singularity. .
But one thing is that both classical mechanics and quantum mechanics have a unified understanding, that is, before the universe was born, the world was nothing and nothingness. What is nothingness and nothingness? It is in a vacuum state, there is no space, no matter, and no time. Because it was the moment of the Big Bang that time, space and matter began to be born.
Quantum mechanics’ conjecture before the emergence of the universe
First of all, quantum mechanics believes that vacuum is not actually empty. Even in the so-called “absolute vacuum”, it is full of energy, and this energy is called vacuum zero-point energy. These energies will continue to appear in the form of positive and negative virtual particle pairs, and they will continue to annihilate. This phenomenon is called quantum random fluctuations.
The vast majority of the universality in the universe is parity conservation, that is, symmetric, but there are also very few asymmetries, that is, symmetry broken. From a philosophical point of view, the world is not perfect. There are always accidents and accidents that destroy the perfect balance.
This is what Yang Zhenning and Li Zhengdao were talking about for the principle of parity non-conservation that won the Nobel Prize in Physics in 1957. This is a shocking theory. Since then, it has provided an important basis for explaining the birth of the universe and the birth of life, and has also changed the direction of later physics and quantum mechanics research.
Symmetry broken creates the universe and life
If the positive matter and anti-matter are exactly the same in the universe, the positive and negative will be annihilated forever, and the universe will not appear.
Before the birth of the universe, in a void and vacuum, energy continued to emerge and annihilate in uncertain fluctuations. However, a very small number of virtual particle pairs appeared to be broken, and there was no annihilation. Positive particles prevailed, so singularities appeared. Up. With the explosion (expansion) of the singularity, time and space and matter were born at the same time, and the singularity continued to expand and became the universe today.
Life is like this from scratch. The universe started with simple light elements (mainly hydrogen, helium, and lithium), through stellar evolution and supernova big bangs, to form more and more heavy elements. So far, mankind has discovered 118 elements. The collision and combination of these elements, in the constant accidental “break”, the matter evolves from inorganic matter to organic matter, and then to cell life.
Many examples of symmetry breaking have been found in the world today, such as non-conservation of parity under weak interaction, asymmetry of particles and antiparticles, symmetry breaking of chiral molecules, and so on. Without these “breaks”, the world would be monotonous, dim, and lose vitality, and there would be no stars, galaxies, or even living things; and the earth’s species would not differentiate and evolve into what it is today.
Nowadays, symmetry breaking has become a concept across disciplines such as physics, biology, sociology, systems theory, etc. It is a theory that explains the differences in things, indicating that the world has both symmetry and asymmetry. The difference and the broken symmetry have created today’s colorful world.
Parallel universe and multiverse theory
Multiverse theory holds that there are many or even infinite universes, and this theory is also based on the symmetry breaking of quantum fluctuations. As mentioned above, since the singularity of the universe is born from the quantum fluctuations in the zero-point energy of the vacuum, it is the symmetry breaking of the virtual particle pair, then it is impossible for only one virtual particle pair to give birth to the singularity due to the broken symmetry. There may be an infinite number of virtual particle pairs whose symmetry is broken, and each breaking creates a singularity, so the universe has an infinite number of them.
The origin of the parallel universe is based on the uncertainty principle of quantum mechanics and the principle of quantum superposition state. The most famous thought experiment is “Schrödinger’s Cat”, which is a cat that is both dead and alive (the details have been mentioned many times, so I won’t go into it here). In the quantum world, every particle has two states, namely, both dead and alive. That is, when I opened the experimental box of “Schrödinger’s Cat” and saw a “dead cat”, there must be a “living cat” in another world, and this state of being both dead and alive is always present. Splitting constantly, so there are countless parallel universes in the universe.
This is the simple origin of multiple universes and parallel universes. These theories are very complicated and profound. It takes a long time to make it clear, so I won’t talk about it today. Of course, these statements are still based on certain inferences of quantum mechanics. The consensus of the scientific community is that whether it is parallel universes or multiverses, they are all different time and space, and they cannot cross the boundary. Therefore, this kind of conjecture will never be possible. Confirmed.
The end of the universe
At present, the scientific community has many conjectures about the destination of our own universe, mainly including the heat death theory, the big tear theory, and the big collapse theory.
The heat death theory means that in the far future, all the heat in the universe is exhausted, and the entire universe is in a state of thermal equilibrium. There is no flow or exchange of heat and particles. As a result, the universe is dead, space and time disappear and return to nothingness; the big tear theory It is based on the fact that the expansion of the universe is getting faster and faster. If the ultimate gravitational force is unable to suppress the increasing trend of the expansion of the universe, atoms and elementary particles will not be able to withstand the destruction of the expansion of the universe. All elementary particles will be torn apart, and the universe will fall apart and become nothingness. ; Great collapse means that the universe expands to a certain stage, and the force of gravitational contraction has the upper hand. From the stop expansion to the beginning of the contraction of the universe, due to the influence of gravity, it will shrink faster and faster, forming a tendency of collapse, and finally contracting back to one Singular point.
The current theory is that dark energy occupies 68.3% of the total energy of the universe and dominates the expansion of the universe; dark matter accounts for 26.8% of the total mass and energy of the universe and dominates the shrinkage of the universe. The contest between them has been going on, and in the end, whoever is the winner determines whether the end of the universe is torn or collapsed. No matter what kind of destination, the universe will start again, but this has nothing to do with human beings.
Because human beings are nothing but a passer-by in the evolution of the universe, and it is likely to be an extremely short passer-by, like a wave in a long river, fleeting.