Universe is the whole world around us. These are other planets and stars, our planet Earth, its plants and animals, you and me - all this is the Universe, including what is beyond Earth - cosmic space, planets, stars. This is matter without end and edge, taking on the most diverse forms of its existence.
Universe is everything that exists. From the smallest dust grains and atoms to huge accumulations of the matter of stellar worlds and stellar systems. The universe, or cosmos, is made up of giant clusters of stars.
Where did all this come from?
There are several theories, the most popular of which is the big bang theory.
70 years ago, American astronomer Edwin Hubble discovered that galaxies are located in the red part of the color spectrum. This, according to the "Doppler effect", meant that they were moving away from each other. Moreover, the light from more distant galaxies is “redder” than the light from closer ones, which indicated a lower speed of the distant ones. The picture of the expansion of huge masses of matter strikingly resembled the picture of an explosion. Then the theory was proposed big bang.
According to calculations, this happened about 13.7 billion years ago. By the time of the explosion, the Universe was a "point" 10-33 centimeters in size. The length of the current Universe is estimated by astronomers at 156 billion light years (for comparison: a “point” is so many times smaller than a proton - the nucleus of a hydrogen atom, how many times the proton itself is smaller than the Moon).
The substance at the “point” was extremely hot, which means that a lot of light quanta appeared during the explosion. Of course, everything cools down over time, and the quanta scatter over the emerging space, but the echoes of the Big Bang should have survived to this day.
The first confirmation of the fact of the explosion came in 1964, when American radio astronomers R. Wilson and A. Penzias discovered a relic electromagnetic radiation with a temperature of about 3° Kelvin (-270° C). This discovery, unexpected for scientists, was regarded in favor of the Big Bang.
So, from the superhot cloud of subatomic particles gradually expanding in all directions, atoms, substances, planets, stars, galaxies began to gradually form, and finally life appeared. The universe is still expanding, and it is not known how long this will continue. Perhaps someday she will reach her limit.
The Big Bang theory made it possible to answer many questions that confronted cosmology, but, unfortunately, or perhaps fortunately, it also raised a number of new ones. In particular: what happened before the Big Bang? What caused the universe to start heating up to an unimaginable temperature of over 1032 degrees K? Why is the Universe surprisingly homogeneous, while in any explosion the matter scatters in different directions extremely unevenly?
But main riddle is, of course, a "phenomenon". It is not known where it came from, how it was formed. In popular science publications, the topic of "phenomenon" is usually omitted altogether, and in specialized scientific publications it is written about as something unacceptable from a scientific point of view. Stephen Hawking, a world-famous scientist, professor at the University of Cambridge, and J. F. R. Ellis, professor of mathematics at the University of Cape Town, in their book “The Long Scale of Space-Time Structure” say so directly: “The results we have achieved support the concept that The universe originated a finite number of years ago. However, the starting point of the theory of the emergence of the universe as a result of the Big Bang - the so-called "phenomenon" - is beyond the known laws of physics.
At the same time, it should be taken into account that the problem of the “phenomenon” is only a part of a much larger problem, the problem of the very source of the initial state of the Universe. In other words: if the Universe was originally compressed into a point, then what brought it to this state?
In an attempt to circumvent the "phenomenon" problem, some scientists propose other hypotheses. One of them is the theory of the “pulsating Universe”. According to her, the Universe is infinitely over and over again either shrinking to a point or expanding to some boundaries. Such a universe has neither beginning nor end, there are only expansion-contraction cycles. At the same time, the authors of the hypothesis argue that the Universe has always existed, thereby seemingly removing the question of the “beginning of the world”.
But the fact is that no one has yet provided a satisfactory explanation of the mechanism of pulsation. Why is it happening? What are the causes? Nobel Laureate, physicist Steven Weinberg in his book "The First Three Minutes" indicates that with each next pulsation in the Universe, the ratio of the number of photons to the number of nucleons must inevitably increase, which leads to the extinction of new pulsations. Weinberg concludes that, therefore, the number of pulsation cycles of the Universe is finite, which means that they must stop at some point. Consequently, the "pulsating Universe" has an end, and therefore, has a beginning.
Another theory of the origin of the Universe is the theory of “white holes”, or quasars, which “spit out” entire galaxies from themselves.
The theory of "spatio-temporal tunnels" or "space channels" is also curious. The idea of them was first expressed in 1962 by the American theoretical physicist John Wheeler in the book Geometrodynamics, in which the researcher formulated the possibility of extra-spatial, extraordinarily fast intergalactic travel. Some versions of the concept of "space channels" consider the possibility of using them to travel to the past and future, as well as to other universes and dimensions.
Stanford physicist Andrei Linde asks questions that the Big Bang theory cannot answer. Some of them were voiced in a 2007 Stanford Alumni magazine article: “What Exactly Exploded? Why did it explode at this particular moment and everywhere at once? What existed before the Big Bang?
From Linde's point of view, the Big Bang was not a single event, but rather a disorderly and dispersed inflation. He developed his chaotic theory of inflation in the 1980s: Big Bang-like expansions could happen anywhere in space, given enough potential energy.
“We assumed that the entire universe was created at one moment,” says Linde. - But actually it is not".
CMB research in the 1990s showed varying intensities, providing some evidence to support the chaotic theory of inflation.
Linde believes that when viewed from a very broad perspective, the cosmos does not fit into the framework created by science: “Instead of a universe where there is one law of physics, eternal chaotic inflation creates a picture of a self-perpetuating and eternal multiverse where everything is possible,” says Linde. - Parallel lines can intersect at a very long distance. The laws of physics can change... We just can't see when it happens. We are like ants inside a huge ball.”
Other theories about the origin of the universe:
Ekpyrotic theory
Adherents of this theory believe that there is a universe parallel to ours, which from time to time collides with a "sister". The energy of the collision leads to huge perturbations of space, as a result of which particles appear, which then form gaseous nebulae, galaxies, stars and other cosmic bodies.
After the collision, the universes scatter, but the further they scatter, the stronger they begin to attract each other (and why not?). Gradually, they begin to approach again, and by that time there are no stars and other objects in both Universes, everything is evenly distributed according to the Second Law of Thermodynamics.
The universes collide again, and again the energy of the collision leads to particles, and so on, it's an endless cycle.
white holes
We have all heard about the existence of black holes. In general, on this moment their existence can only be guessed from the perturbation of gravitational fields / deflection of light. But scientists are already talking about the existence of white holes. After all, if matter is absorbed by a black hole, it must be ejected somewhere, right?
And in theory, points where matter is emitted rather than absorbed do exist. So far, they have not been detected, but adherents of this theory do not leave hope for the discovery of a white hole in the near future.
Generally speaking, the existence of white holes, if they are actually discovered, violates several fundamental laws of physics at once. And if a really white hole is discovered, then the foundation of current science will have to be patched up, and very thoroughly (for the umpteenth time, by the way).
The universe is the creation of a black hole
A very interesting theory, according to which black holes, throwing matter out of nowhere, in fact, create new universes that appear even faster than mushrooms after rain. Each particle absorbed by a black hole can be the beginning of a new universe, after the particle, endowed with enormous energy, explodes. It will be a Big Bang, and there are a lot of such explosions.
Each generated Universe, in turn, generates new black holes, and those - new Universes. In general, the head is spinning, it is very difficult to imagine all this endless whirlwind.
Quantum theory of the worlds
This theory is often used by science fiction writers in their works. Its essence is in the constant branching of variations. For example, now you decide whether to go to the store or turn on the TV. In one invariance you go to the store, in the other you turn on the TV. We already have two Universes, which differ very little from each other, but the farther, the stronger the differences.
And in general - variations "branch" depending on many factors, including the behavior of atoms that move in different directions, and so on. As a result, billions of billions of new invariances appear every moment, and the farther they are from each other, the more these Universes differ.
Figuratively, this can be imagined as a fan, each blade of which is infinitely divided, and each of the subsequent parts is divided again, and so on ...
In the scientific world, it is generally accepted that the Universe originated as a result of the Big Bang. This theory is based on the fact that energy and matter (the foundations of all things) were previously in a state of singularity. It, in turn, is characterized by the infinity of temperature, density and pressure. The singularity state itself overrides all known modern world laws of physics. Scientists believe that the Universe arose from a microscopic particle, which, due to unknown reasons, came into an unstable state in the distant past and exploded.
The term "Big Bang" began to be used since 1949 after the publication of the works of the scientist F. Hoyle in popular science publications. Today, the theory of the “dynamic evolving model” has been developed so well that physicists can describe the processes occurring in the Universe as early as 10 seconds after the explosion of a microscopic particle that laid the foundation for everything.
There are several proofs of the theory. One of the main ones is the relic radiation, which permeates the entire Universe. It could have arisen, according to modern scientists, only as a result of the Big Bang, due to the interaction of microscopic particles. It is the relic radiation that makes it possible to learn about those times when the Universe looked like a blazing space, and there were no stars, planets and the galaxy itself. The second proof of the birth of everything that exists from the Big Bang is the cosmological redshift, which consists in a decrease in the frequency of radiation. This confirms the removal of stars, galaxies from milky way in particular and from each other in general. That is, it indicates that the Universe expanded earlier and continues to do so until now.
A Brief History of the Universe
- 10 -45 - 10 -37 sec- inflationary expansion
- 10 -6 sec- the emergence of quarks and electrons
- 10 -5 sec- the formation of protons and neutrons
- 10 -4 sec - 3 min- the emergence of nuclei of deuterium, helium and lithium
- 400 thousand years- formation of atoms
- 15 million years- continued expansion of the gas cloud
- 1 billion years- the birth of the first stars and galaxies
- 10 - 15 billion years- the appearance of planets and intelligent life
- 10 14 billion years- termination of the process of birth of stars
- 10 37 billion years- depletion of the energy of all stars
- 10 40 billion years- Evaporation of black holes and birth elementary particles
- 10 100 billion years- completion of the evaporation of all black holes
The Big Bang theory has become a real breakthrough in science. It allowed scientists to answer many questions regarding the birth of the universe. But at the same time, this theory gave rise to new mysteries. Chief among them is the cause of the Big Bang itself. The second question to which modern science has no answer is how space and time appeared. According to some researchers, they were born together with matter, energy. That is, they are the result of the Big Bang. But then it turns out that time and space must have some kind of beginning. That is, a certain entity, constantly existing and not dependent on their indicators, could well initiate the processes of instability in a microscopic particle that gave rise to the Universe.
The more research is done in this direction, the more questions arise for astrophysicists. The answers to them await mankind in the future.
In 1926, scientists realized that our Galaxy is not the only one in the Universe, and after a few more years, the Universe suddenly ceased to be static and eternal: it turned out that it was expanding. But what future awaits her in this case? Is it possible that the universe just arose out of nothing? The well-known American scientist, physicist and specialist in the field of cosmology Lawrence Krauss spoke about the conclusions of modern science. T&P took notes of his lecture.
What shape is the universe?
Today, with the help of the Hubble telescope, we can see more than 100 billion galaxies, and each of them may contain hundreds of billions of stars. But how did all this come about? Why is there something and not nothing? This is a basic question for many religions. It seems that someone had to create such a huge Universe that it is impossible to get all this from nothing. I want to tell you why this is not so, why all these galaxies and stars can arise simply due to the laws of physics.
In 1926, Edwin Hubble learned that our galaxy is not the only one in the universe. And after another three years, he realized that other galaxies are moving away from us. After this amazing discovery, it immediately began to seem that we were at the center of the universe. However, Hubble's observations tell a different story: the universe is expanding, no matter which galaxy you're watching it from.
Until 1929, science believed that the universe was static and eternal. But as soon as we now understand that it is moving, we can find out what happened to it in the past. All galaxies have a single beginning: about 13.8 billion years ago they were all at the same point, which we call the Big Bang. But what will happen to galaxies in the future? Is expansion infinite? This is the question that got me into cosmology and into physics in general.
There are three variants of the geometry of our Universe: it can be closed, open or flat. This does not mean the shape of the Universe itself, but how a plane looks in it, comparable to the size of the Universe itself. For example, if you draw arbitrarily big triangle in a flat universe, then the sum of its angles will be equal to 180 degrees. In the open universe, the lines along which light travels bend, so the sum of the angles of a triangle will be less than 180 degrees. And in a closed Universe, the sum of its angles, on the contrary, will be more than 180 degrees.
According to the theory of relativity, a closed universe will expand and then contract back and eventually collapse, an open universe will expand indefinitely, and a flat universe will expand first and then very gradually slow down and stop. If we can determine what universe we live in, then we will know our future. But how to do that?
Dark matter
“The most beautiful emotion that we are given to experience is the feeling of mystery. It is the fundamental emotion at the origin of all true art and science."
The universe was not created for us, it was simply created. The universe doesn't care about us. We ourselves fill our life with meaning and meaning.
Questions and answers
I have a question about inflation. You said that it was predicted by particle physicists. And what does the inflation of space have to do with particle physics?
Particle physics says that the early universe underwent a transition from one phase state to another. When this phase transition occurs, a huge amount of energy is released, which led to inflation.
Suppose that dark matter turns out to be a particle after all, and we can find it. Will the foundation on which all modern physics is built turn out to be false?
Particle physics predicts the presence of a large number of different particles. And the discovery of each new particle takes the standard model beyond the previous boundaries. If we can find dark matter - yes, many of our ideas will turn out to be wrong, and we will have to think over and develop new laws. But scientists are ready to be wrong. Many of us go to work to prove other scientists wrong, and that's how fame comes.
It is clear what the boundaries of a closed Universe can be. But it is not entirely clear to me what the boundaries of the flat universe in which we are.
A closed universe has no boundaries. Take a balloon, draw a few dots on it and blow it up. The universe is similar to the surface of this ball: it has no boundaries, while expanding so that the distance between points gradually increases.
I have a question that came up while reading books by Richard Dawkins. Our brain is evolutionarily programmed not to understand the Universe, but to solve everyday issues. Are you afraid that at some point science will run into the limits of the brain?
May be. But I'm not afraid. Just like I'm not afraid to live in this universe that has no purpose. Yes, there may be some restrictions human brain but we won't know for sure until we try. That is why you have to keep trying. And, as I understand it, we have not yet managed to hit a wall. Maybe you will have some difficulties, but your children and grandchildren will be able to overcome them. We are constantly moving on, we are constantly overcoming these boundaries. Science is precisely what it is about transcending boundaries.
Maybe not very on topic, but one of the reasons I do quantum computers and artificial intelligence, that maybe they will be able to explain to us what we ourselves cannot understand. Many people are afraid of artificial intelligence, but I think that it can become a better physicist than we are.
- In what role do you see artificial intelligence in your field?
I have no idea. I do not predict closer than 2 trillion years. What will be the future with artificial intelligence depends on us. We must think about the possibilities and be ready for them. One of the options is that we will be left without work. But then we can endlessly walk on scientific conferences and listen to music. In this case, I am pessimistic, because, frankly, I do not really believe in humanity. But let's see what happens. We can still get ready.
- Is it possible to prove that we live in a computer simulation?
A lot of people ask this question. Answer: most likely not.
First, a computer simulation is never perfect. There are dead pixels in which the laws of nature do not work. But we don't see that. Maybe President Trump has such pixels in his head, but in most other cases there are no such pixels. Everything works according to the laws of nature.
Secondly, speaking of being inside a simulation, we must ask the question: what created us? What about our creators? The idea that our existence is a computer simulation is just another version of the question of who created the universe.
But as a physicist, it doesn’t matter to me at all whether I’m in a simulation or not - I’m interested in what laws it was created under.
If you want to prove that our world is a simulation, look for bugs in the program. Maybe in the future we will find them, not yet.
The universe is expanding. Countless space objects are moving away from us faster and faster. Does this mean that our chances of finding other civilizations in this Universe are getting smaller and smaller?
First, before other galaxies finally disappear from sight, we still have 2 trillion years - during this time it is possible to find an extraterrestrial civilization. Secondly, even after 2 trillion years we will have our Galaxy - because galaxies themselves are not expanding.
If everything came from nothing, how did this nothing decide to make the Big Bang 13 billion years ago? And why isn't the Big Bang happening now?
The answer to the first question is I don't know. That is why I do science.
As for the second question. Big explosions may be happening right now, in other dimensions. Space may appear right in front of you, but it will very quickly be separated from our universe. In the multiverse, big explosions can constantly occur, universes appear and collapse.
- Does what you told us about conflict with the law of conservation of energy?
To be honest, it doesn't conflict. If you look at hundreds of millions of stars and galaxies, they have a lot of energy. But you just need to add gravitational attraction to this equation, and the total resulting energy of our entire Universe, all matter, will be equal to zero. Thus, energy is conserved. Amazing, right?
- Is it possible to create a model of such a universe in which the laws of physics would be impossible in our universe?
This is exactly what I do most of the time. I am a theoretical physicist, I constantly create models that describe different universes. You need to understand that in most cases I am wrong. I had stunningly beautiful, very good theories that turned out to be wrong. But maybe once in a lifetime I will happen to be right (as was the case with the idea that the universe is expanding with acceleration).
The search is more important than reality itself. Our life is like the myth of Sisyphus, we have no choice. We can get depressed - or we can enjoy the search.
If different laws of physics form in different universes, is there some higher law of physics above all of them, according to which these different laws are formed?
That is, metalaws? May be. Who knows... It's possible. In some theories, for example string theory. But now there is no evidence. Maybe there are laws of mathematics. I don't know what to expect. But this does not prove, of course, the existence of any god.
You live in a country where it is undesirable for a politician to admit that he is an atheist in order not to lose his rating. And we live in a country where about 70-80% of people consider themselves religious people, know nothing and do not want to know about the Big Bang theory. What do you think needs to happen in order for the balance of power in the world to change?
Honestly, I don't care if people are religious or not. When I see people who think the world is 5 or 6 thousand years old, I don't think they are stupid. I think they just lack knowledge. It is already too late for older people to change, but I hope for young people. I want young people to think, not just feel. And it's not even about the facts, because the facts you're in in large numbers find on your smartphone - but they may not be correct. The most important thing is to teach people to ask questions and distinguish between true and false. I think teaching science in school encourages young people to do this.
A physics teacher at school told me that asking what happened before the Big Bang is like bad manners, because the laws of physics do not apply at the singularity point. He said that everyone would laugh if I asked anyone about it. But at the same time, you only talked about this throughout the lecture. So my question is: are the possibilities of human knowledge limited at all?
It's a good question, but you won't like the answer. There is no "before" because time itself originated in the Big Bang. It's very hard to imagine. But the question "What happened before the Big Bang?" might just not matter. And our consciousness, perhaps, lacks the capacity to understand this question and answer it.
But I would like you to keep asking questions and marveling at the universe as it is. It doesn't matter if you don't understand everything. Appreciate her for being more than you can comprehend. We must constantly look ahead, because the Universe can teach us a lot.
Literature
Krauss L. Everything from nothing. M.: Alpina non-fiction, 2019.
Krauss L. Fear of Physics. Spherical horse in vacuum. St. Petersburg: Peter, 2016.
Krauss L. Why do we exist? The greatest story ever told. M.: Alpina non-fiction, 2018.
Krauss L. Universe from nothing. Why God is not needed to create the Universe from emptiness. M.: AST, 2016.
Lens-Like Action of a Star by the Deviation of Light in the Gravitational Field. Albert Einstein Science, New Series, Vol. 84, no. 2188. (Dec. 4, 1936), pp. 506–507.
We thank Maria Lomaeva for her help in preparing the abstract.
We publish abridged recordings of lectures, webinars, podcasts - that is, oral presentations. The opinion of the speaker may not coincide with the opinion of the editors. We ask for links to primary sources, but their provision is at the discretion of the speaker.
Now there is a huge number of assumptions about the possible origin of the universe. But none of them can give a clear answer to main question about how it came about.
It is paradoxical that after studying and analyzing one of the theories and finding a sufficient number of convincing judgments in it, understanding the other theory also provides a considerable number of arguments.
That is why the search for an unambiguous answer to this question has been going on for many years.
At the moment, there are 3 main theories of the origin of the universe:
- theological;
- The Big Bang Theory";
- scientific and philosophical theory.
Theological approach
If we consider one of the oldest theories of the origin of the Universe, described in the Bible, then the origin of the world dates back to 5508 BC.
The theological point of view about the origin of the world has been known for a long time, but its supporters are mainly deeply religious people and the clergy.
This theory is most often criticized by scientists who look at the origin of the world and its structure in a completely different way.
If you turn to explanatory dictionary, then we will read there that the Universe is a worldview system that includes cosmic infinity and all the bodies that are in it.
A more alternative definition of the concept of "Universe" is "a bunch of stellar bodies and galaxies."
The big bang is the beginning of the universe
From a scientific point of view, popular theory explaining the origin of the universe is the so-called "Big Bang" theory.
This version says that about 20 billion years ago the Universe looked like a small grain of sand. But despite the meager size of this substance, its density was more than 1100 g/cm3. Naturally, at that time this substance did not include stars, planets or galaxies. It represented only a certain potential for the creation of many celestial bodies.
The high density caused an explosion that could divide a grain of sand into millions of parts, from which the Universe was formed.
There is another theory of the origin of the universe. Its essence echoes the Big Bang theory. The only exception is the fact that in the second theory the Universe supposedly did not arise from matter, but from vacuum. In other words, the world came into being as a result of an explosion in a vacuum.
The word "vacuum" is translated from Latin as "emptiness", but by emptiness it is customary to understand not the generally accepted meaning of this word, but a certain state in which all things exist. Vacuum tends to change its structure in the same way as water does, turning into solid or gas. In the process of one of these transitions from one state to another, an explosion occurred that gave birth to the Universe.
The development of the "Big Bang" theory made it possible to answer many important questions, but at the same time put before scientists even more new ones. For example, what led to the instability of the singularity point and what state did the particle have before the big bang? One of the main mysteries remains the origin and nature of space and time.
Scientific and philosophical theory
In addition to theological and scientific hypotheses that explain the origin of the Universe, there is also a scientific and philosophical approach to this issue.
The scientific and philosophical theory considers the creation of the Universe by a certain reasonable Beginning. This approach implies the impermanent existence of the world, since there is a fixed point of origin. The theory also describes the constant growth and development of the universe. Such conclusions were made by scientists involved in the study of the composition and radiance of stellar bodies.
“Studies of the Milky Way, carried out in the 30s of the twentieth century, found that the stellar radiance is shifted towards the red region of the spectrum and the more distant the star is from the Earth, the more pronounced it is. It was this fact that became the basis for the conclusions of scientists about the constant growth and expansion of the Universe.
The universe, which is constantly photographed by scientists, is constantly changing.
Another fact confirming the expansion of the universe is a phenomenon called the "death" of a star.
By chemical composition the body of a star consists of hydrogen, which takes part in many reactions and turns into heavier elements. After most of the hydrogen has reacted, the "death" of the star occurs. Some theories claim that the planets are the result of this phenomenon.
These studies confirmed another assumption: hydrogen decay is a natural and irreversible process, and the Universe is moving towards its end.
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The origin of the universe remains one of the main mysteries of science. Since the beginning of observations starry sky mankind tried to understand how everything that surrounds it arose, and what is there outside of our world. With the development of technology, many obeyed him natural phenomena and even the expanses of space, but no one has yet established how the Universe was born. However, astronomers have put forward many theories in this regard, some of them are quite logical and plausible.
The Big Bang Theory
The main theory of the origin of the universe in its current state is the big bang theory. This term was first used by the British astronomer F. Hoyle in 1949. At the same time, the scientist himself considered this assumption about the origin and evolution of the Universe to be erroneous.
The very same ideas about the expansion of the universe and its development as a result of an explosive process arose at the beginning of the 20th century. This was facilitated by Albert Einstein, who published his theory of relativity. The non-stationary solution of his gravitational equation led the Soviet physicist Friedman to the hypothesis that the Universe is an ever-expanding object. According to his version, at first it was a very dense, homogeneous substance. As a result of the big bang, it began to spread, forming the elements of the cosmos familiar to us - galaxies, nebulae, stars, planets and other bodies.
The theory of the origin of the Universe according to Friedman has been repeatedly subjected to additions and improvements. In 1948, astrophysicist Georgy Gamow published a paper in which he described the primordial matter before the Big Bang not only as very dense, but also as very hot. Thermonuclear fusion reactions constantly took place in it, as a result of which the nuclei of the lungs were formed. chemical elements. The electromagnetic radiation emitted in this case has survived to this day, but in a cooling form. The theory was confirmed almost 20 years after scientists were able to discover and measure the temperature of the cosmic background. The study of relic radiation also helped to establish the age of the universe and the distribution of matter in it.
Modern view of the origin of the universe
- The Big Bang Theory - describes what became the trigger mechanism for the expansion of primary matter.
- Inflationary theory - considers the causes of the expansion of matter.
- Friedman's expansion model - describes the processes of distribution of matter in space.
- Hierarchical theory - describes the emergence of all structures of the cosmos.
Chronology of events in the Big Bang theory
The theory of the evolution of the universe implies that before the Big Bang, the entire universe was in a fundamentally different state. And after - it went through stages of development, thanks to which it was filled with particles, chemical elements and other structures. They also served building material for all space bodies and objects. Each epoch of development has its own duration from insignificant fractions of a second to billions of years. Let's try to state the theory of the origin of the Universe briefly and in simple language.
The Age of the Singularity
The Big Bang and the origin of the Universe in its modern form was preceded by the stage of cosmological singularity. This is the state of the Universe, in which matter has almost infinite values of density and temperature, and it itself tends to zero.
The cosmological singularity is one of the most difficult questions in modern science. It is impossible to establish exactly what happened before the Big Bang. But the infinite density of early universal matter cannot be accompanied by its infinite temperature. Therefore, a singular universe contradicts the modern laws of physics.
According to some assumptions, the era of the singularity did not exist at all. Even according to the assumption of a group of scientists, including S. Hawking, everything that exists could arise from an absolute vacuum (“nothing”) due to system fluctuations. According to another theory, the Big Bang only led to the formation of the Metagalaxy, as a "bubble" in dense matter Universe. There is also a hypothesis that universes are formed due to singularity ruptures within black holes. It is not possible to establish for certain what happened before the Big Bang.
Planck era
So, a catastrophic process took place in the primary universe, as a result of which the matter began to rapidly expand and cool. Moreover, in order to form all the structures of outer space, an explosion had to occur everywhere. This is the point of reference for the emergence of the universe in its present form.
In the period from zero to 10 -43 seconds, the substance of the Universe had physical parameters (temperature, energy, density) corresponding to Planck's constants. In such conditions of the Planck era, particles were born.
The era of the great unification
In the period from 10 -43 to 10 -35 seconds after the Big Bang, gravitational forces arose in a relatively stable system. They subsequently contributed to the formation of stars and planets. Primary matter ceased to be uniformly dense. But the electromagnetic and nuclear interactions were still combined in it, so any physical and chemical parameters for this substance do not make sense.
Age of inflation
At the transition to this stage of evolution, the Universe began to expand rapidly. This made it possible to redistribute the high-density isotropic primary matter. The epoch took a period of time from 10 -35 to 10 -32 seconds from the explosive process.
Electroweak era
By this point, the strong nuclear force, like gravity, has been separated from primordial matter. The period from 10 -32 to 10 -12 seconds is the moment of birth of such elementary particles as the Higgs boson and W-, Z-particles. Symmetry to the universal substance is finally destroyed.
quark epoch
From 10 -12 to 10 -6 seconds, all four fundamental interactions begin to exist separately. The entire matter of the Universe is a "quark soup" of massless and structureless fundamental particles.
Andron epoch
Androns, particles with a strong nuclear force, began to form from fundamental particles. It is from them that nucleons are formed, forming atomic nuclei, protons and neutrons. The entire process of andronization took about a hundred seconds after the Big Bang.
lepton epoch
The first three minutes of the existence of the Universe is the formation of leptons, including their subspecies - neutrinos. These are yet another fundamental structure of the universal substance, from which everything in the universe was later built.
proton epoch
More than 300 thousand years were spent on the primary process of nucleosynthesis of light chemical elements and the redistribution of the substance of the Universe. It began to dominate radiation, which slowed down the expansion of outer space. The end of this stage was marked by the possibility of movement of thermal photons.
Dark Ages
Not a single cosmic structure familiar to us existed in the first 500 million years after the emergence of the Universe. It was filled with a hydrogen-helium mass and relict thermal radiation propagating throughout its entire space.
Reionization
Gradually, clouds of hydrogen and helium began to shrink under the influence of gravity, and the processes of thermonuclear fusion began to emerge in them. The first stars appeared. They began to gather in clusters called galaxies. In the center of the forming galaxies, a source of the most powerful radiation and gravitational attraction arose - a quasar. This process took over 300 million years.
The Age of Substance
Young stars form protoplanetary disks around themselves, from which entire planetary systems subsequently form. In this era, 4.6 billion years ago, the solar system with all the planets surrounding it arose. The entire history of the universe continues for more than 13.7 billion years.
Future of the Universe
The theory of the origin of the universe through the Big Bang is officially recognized in the scientific world. According to her main statements, outer space still continues to evolve and completely new structures are replacing some structures. There are two opposite versions of the further development of events:
- Big gap. If the Universe continues to expand further, then in the future the gravitational interaction between its elements will begin to rapidly weaken. There will be a decay of galaxies and their clusters. After that, separate star systems will disintegrate, where the gravity of the star will not be able to keep the planets around it. Gradually, all the elements of the Universe are destroyed again to elementary particles, the laws of physics will cease to make sense. What happens next is impossible to predict.
- Big compression. This scenario describes the assumption that outer space will gradually slow down its expansion and begin to contract back. All its elements form a single mega cluster, in which the processes of birth, evolution and death of galaxies will continue. However, matter will continue to shrink, resulting in the formation of one giant galaxy. Outer space will begin to heat up again, the cosmic microwave radiation will destroy the planets and stars. All structures will pass into the state of elementary particles. The universe will take on its original form before the Big Bang.
Any of the main scenarios of the death of the Universe in its current state involves the decay of all its structures to fundamental particles and the cessation of any forces of interaction. Is it really going to be so, predict modern science impossible.
The main theories of the origin of the universe
The Big Bang is not the only modern understanding of the origin and evolution of the universe. The scientific world knows many theories of the origin of the world, the main of which are:
- String theory. Her main statement is that everything that exists consists of tiny energy threads. Such quantum strings can be stretched, bent and located in any direction, which makes outer space multidimensional. And each of these dimensions has its own evolutionary stages.
- Theory of the stationary Universe. According to this version, new matter constantly arises in the expanding space of space, which makes the entire system stable. The idea was popular in the middle of the 20th century, but after the discovery and study of the cosmic microwave background, it had practically no supporters left.
It is possible that all the assumptions about the origin of the universe, recognized now in the scientific world, will not be refuted in the future. And the further and longer humanity explores space, the more new answers and questions it finds.
