What is the universe?

Or what is the world we live in?

In what form a world is born already determines to some extent in what form it will end.

If a world was really created by the all-powerful and all-knowing gods in seven days, as the legend says, then it will eventually be destroyed in a catastrophe of the wrath of the gods, as the legend says.

In other words, if a world can really be parsed, then it must ensure that the world is rational from the beginning of its birth, and that everything is generated according to some kind of rule, and not a sudden thought of some unknown being.

For example, in order to understand the principle of the human body, it is necessary to first ensure that the human body really evolved step by step from ancient apes, and was not created by some god.

Otherwise, the final interpretation will always be with the gods, and human beings will never be able to figure out their own mysteries.

Then, the retina that is upside down, the recurrent laryngeal nerve that goes around the long way, the trachea and esophagus that share the opening, the fatal point of the temple that lacks protection, the completely redundant (anti-harmony) head for men, and the yin (anti-harmony) stem and bone that men lack in order to better reproduce will all be small defects left by the gods in the process of creating human beings because of their carelessness.

It is not in the process of evolution, human beings make active and passive choices in order to better survive and adapt to the environment.

For Richard, what he pursues is to analyze the current world, so that the current world, like the earth, becomes a universe that conforms to reason, rules, and logic.

What kind of universe is the universe where the earth is located?

Everything was decided at the moment of birth.

According to the most consensus research results on Earth, the universe in which the Earth is located was born from a Big Bang that is unique in the world, the so-called Big Bang theory.

In the Big Bang theory, the initial state of the universe is called the singularity.

It is a point where the volume is infinitely small, the density is infinite, the gravitational force is infinite, and the curvature of space-time is infinite, at which none of the laws of physics are currently known, and neither space nor time has any meaning.

In this state, the temperature of the universe is about 10^32 degrees, which is the so-called Planck temperature. At such temperatures, not to mention the atoms that form the basis of matter, even the protons and neutrons in the nucleus, and even the more basic particles, quarks, do not exist.

At this time, the universe is just a pot of highly concentrated energy soup.

Suddenly, at one moment, the singularity exploded, and the volume of the universe began to expand dramatically, increasing exponentially.

Over the next few microseconds, quarks combine into protons and neutrons in a ratio of 7:1, but they are unable to form stable nuclei. Because they are constantly harassed by neutrinos and antineutrinos, the anti-beta decay nuclear reaction triggered by them greatly inhibits the occurrence of nuclear synthesis.

This continued until the age of the universe was close to one second, and the temperature of the universe dropped to the level of 10^11 degrees, that is, about tens of billions of degrees. Neutrinos and antineutrinos finally stopped interacting with nucleons, and Big Bang nucleosynthesis really began.

Then, when the age of the universe reaches two or three minutes, hydrogen, isotopes of hydrogen, helium elements, and isotopes of helium appear in sequence.

Among them, the isotope of hydrogen, deuterium (one proton, one neutron), is an intermediate product in the nuclear reaction chain, and a large amount of deuterium finally forms helium (two protons, two neutrons) through different paths.

By the time the age of the universe reaches 3 minutes, almost all neutrons are in helium. Because the ratio of protons to neutrons was 7:1 when the universe was born, the mass ratio of hydrogen to helium at this time was 6:2, or 3:1.

In other words, at this time, the universe is 75% hydrogen and 25% helium, and their atomic numbers are 1 and 2, and their atomic weights are 1 and 4, respectively.

After that, the nuclear reaction continues, and in a high-temperature environment, particles collide constantly, from small particles to large particles, and from particles with low atomic number, to particles with high atomic number. However, due to the limitations of physical principles, there are no stable atoms with atomic weight 5 and 8 in the universe, and there is a stable atom lithium 6 with atomic weight 6, and the reaction cross-section is very small, so the next ion that continues to be born from nuclear reactions is the isotope of lithium, lithium 7.

In the course of this nuclear reaction, the universe expands dramatically, becomes larger and larger, and the temperature drops faster and faster. By the time the nuclear reaction produced a small amount of lithium-7, the universe had become very cold and the nucleosynthesis was almost over.

At one hour of the age of the universe, nucleosynthesis ceases completely, and the composition of matter in the universe is about 75% hydrogen, 25% helium, and a very small amount of lithium7, like a large marshmallow-like gaseous nebula.

This state has remained at the age of the universe for about 1 billion years, from one hour of age to the age of the universe.

When the universe is 1 billion years old, certain locations of gaseous nebulae, because they contain more matter, will continue to attract more material around them under the action of gravitational pull. The density becomes higher and higher, and eventually when the gravitational force is greater than the internal support force, a gravitational collapse occurs.

After the gravitational collapse, an area of gaseous nebula will split into smaller and smaller fragments, and in each fragment, the collapsed gas will release gravitational potential energy in the form of thermal energy. As its temperature and pressure increase, these fragments slowly condense into a superthermally rotating gas called the protostar, which is how the first generation of stars is formed.

After the formation of the first generation of stars, in the interior of the core, because of the high temperature environment, nucleosynthesis began to restart, and elements with larger atomic numbers and atomic weights began to synthesize sequentially.

First of all, it is the already familiar element of hydrogen that is nucleated into helium through fusion. The energy from this fusion process is also used to combat the gravitational collapse caused by gravity and ensure the stability of the star's volume.

When the hydrogen element is all depleted, the equilibrium state of fusion energy and gravitational force is broken, and the star undergoes a second gravitational pull and collapses itself, so that the core temperature and pressure rise sharply, reaching the conditions of helium fusion, through the fusion of helium, the nucleus becomes carbon, oxygen, etc.

When the helium is exhausted, the third gravitational collapse begins again, the star collapses again, the core temperature and pressure further increase, and the carbon and oxygen elements begin to fuse and nucleate into silicon.

If the star is not massive enough, it will die during one of the collapses and evolve into a white dwarf (about one-tenth the mass of the Sun) or a red giant (a star with a mass ten times less than the Sun). And if the star is massive enough to continue like this, the elements after lithium will continue to be generated, such as neon, magnesium, silicon, sulfur, calcium......

However, there is still a limit to this synthesis.

This limit is iron.

In the core of a very massive star, after several collapses, the elements fuse and nucleosynthesis to form iron.

After most of the mass of the stellar core has turned to iron, the pressure created after the core of the star has become an iron core, is already very high. As a result, most of the electrons in the central part of the iron element are pressed into the nucleus, which combines with protons and becomes neutrons, so that the core is almost entirely neutrons.

The neutrons are extremely tight, so the iron atoms that want to fuse come to the surface of the neutrons and are blocked, like a ball hitting a wall, and are very bounced back and unable to enter the core.

In this way, no matter how much energy the star provides to the core, it will not allow the iron to carry out the next step of fusion, and the life process of the star will be locked in. At this time, the elements of the star from the outer to the innermost are hydrogen, helium, carbon, silicon, and iron.

After this goes on for a while, the fusion of the stars stops, and under the gravitational pull, the stars begin to collapse again.

Because there will be no new fusion restart this time, the star will produce an unprecedented superexplosion, known as the supernova explosion.

In this state, in a very short period of time, the temperature and pressure reach a new high, and the elements after iron are formed, such as nickel, copper, zinc, etc., all the way up to the element uranium.

Uranium is the element with the largest atomic number in nature, and elements that exceed the atomic number of uranium can only be synthesized artificially and cannot be obtained in nature.

This is the universe in which the Earth is located.

In cognition, everything in the universe where the earth is located is currently composed of the energy soup of the original singularity through explosion and nucleosynthesis.

In this universe, the most fundamental components of every living thing and every object can be traced back to an explosion.

In this universe, all life is not sacred because they all have the same past.

Their end, too, is the same, that they will eventually die.

After that, dust returns to dust, and earth returns to earth, forming their particles, and then forming new life.

It's a cycle, it's a kind of reincarnation that belongs to science, your head could become a white cat for the next century, and your hands could come from the spine of a saber-toothed tiger in ancient times.

You, me, and him are actually one.

In this universe of material cycles, almost nothing is eternal, and the only eternal possibility is the ever-increasing entropy.

The universe will continue to expand, and the Plante temperature, which began with the Big Bang at the singularity, will continue to decrease, eventually gradually moving towards absolute zero.

Slowly, all the stars will run out of energy, one by one, and the whole universe will become darker and darker. Slowly, black holes continue to form and dominate the universe. Slowly, the black hole continued to release Hawking radiation, and even the black hole itself began to disappear.

Eventually, the entire universe reaches a state of maximum entropy, and all matter is evenly distributed in the universe. The universe became monotonous and dead, losing all vitality and reaching the end of heat death that had been determined since birth—when the scorching energy soup of the singularity exploded, it was determined that at some point in the distant future, it would finally be completely cooled.

The hot soup is cold, and death is eternal!

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