Perhaps scientists have come close to solving the most intriguing mystery of the universe: are there other universes besides ours?
Albert Einstein throughout his life tried to create a "theory of everything", which would describe all the laws of the universe. Did not have time.
Astrophysicists today assume that the best candidate for this theory is superstring theory. It not only explains the expansion processes of our Universe, but also confirms the existence of other universes near us. Cosmic strings represent distortions of space and time. They can be larger than the Universe itself, although their thickness does not exceed the size of an atomic nucleus.
However, despite its amazing mathematical beauty and integrity, string theory has yet to find experimental confirmation. All hope for the Large Hadron Collider. Scientists expect from him not only the discovery of the Higgs particle, but also some supersymmetric particles. This will be a strong support for string theory, and therefore other worlds. In the meantime, physicists are building theoretical models of other worlds.
1950s. Worlds of Everett
The first about parallel worlds in 1895 told earthlings by science fiction writer Herbert Wells in the story "A Door in a Wall". 62 years later, Princeton University graduate Hugh Everett impressed his colleagues with the topic of his doctoral dissertation on the splitting of worlds.
Here is its essence: every moment each universe splits into an unimaginable number of its own kind, and the next moment each of these newborns splits in exactly the same way. And in this huge multitude there are many worlds in which you exist. In one world, you are on the subway while reading this article; in another, you are on an airplane. In one - you are a king, in another - a slave.
The impetus for the multiplication of worlds is our actions, Everett explained. As soon as we make a choice - "to be or not to be", for example, - in the blink of an eye from one universe, two came out. In one we live, and the second - by itself, although we are present there.
Interesting, but … Even the father of quantum mechanics, Niels Bohr, remained indifferent to this crazy idea then.
1980s. Worlds Linde
The theory of the many-worlds could be forgotten. But again a science fiction writer came to the aid of scientists. Michael Moorcock, by some instinct, settled all the inhabitants of his fabulous city of Tanelorn in the Multiverse. The term Multiverse immediately flashed across the writings of serious scholars.
The fact is that in the 1980s, many physicists had already matured the conviction that the idea of parallel universes could become one of the cornerstones of a new paradigm of science about the structure of the universe. The main proponent of this beautiful idea was Andrey Linde. Our former compatriot, employee of the Physics Institute. Lebedev at the Academy of Sciences, and now a professor of physics at Stanford University.
Linde builds his reasoning on the basis of the Big Bang model, which resulted in a lightning-expanding bubble - the embryo of our Universe. But if some kind of cosmic egg turned out to be capable of giving rise to the Universe, then why cannot one assume the possibility of the existence of other similar eggs? Asking this question, Linde built a model in which inflationary universes emerge continuously, branching off from their parents.
For illustration, one can imagine a certain reservoir filled with water in all possible states of aggregation. There will be liquid zones, blocks of ice and vapor bubbles - and they can be considered analogs of parallel universes of the inflationary model. She represents the world as a huge fractal consisting of homogeneous pieces with different properties. Moving around this world, you will be able to smoothly move from one universe to another. True, your journey will last for a long time - tens of millions of years.
1990s. Worlds of Rhys
The logic of reasoning of the professor of cosmology and astrophysics at Cambridge University Martin Rhys is approximately the following.
The probability of the origin of life in the Universe is a priori so small that it looks like a miracle, argued Professor Rice. And if you do not proceed from the hypothesis of the Creator, then why not assume that Nature randomly gives birth to many parallel worlds, which serve as a field for her experiments to create life.
According to the scientist, life arose on a small planet orbiting an ordinary star of one of the ordinary galaxies of our world for the simple reason that its physical structure favored it. Other worlds in the Multiverse are likely empty.
2000s. Worlds of Tegmark
Max Tegmark, a professor of physics and astronomy at the University of Pennsylvania, is convinced that universes can differ not only in location, cosmological properties, but also in the laws of physics. They exist outside of time and space and are almost impossible to portray.
Consider a simple universe consisting of the Sun, Earth and Moon, a physicist suggests. For an objective observer, such a universe appears as a ring: the Earth's orbit, "smeared" in time, as if wrapped in a braid - it is created by the trajectory of the Moon around the Earth. And other forms personify other physical laws.
The scientist likes to illustrate his theory with the example of playing
"Russian roulette". In his opinion, every time a person pulls the trigger, his universe splits into two: where the shot took place, and where it was not. But Tegmark himself does not risk carrying out such an experiment in reality - at least in
our Universe.
Andrey Linde is a physicist, creator of the theory of an inflating (inflationary) Universe. Graduated from Moscow State University. He worked at the Physics Institute. Lebedev Academy of Sciences (FIAN). Since 1990 - Professor of Physics at Stanford University. Author of more than 220 works in the field of particle physics and cosmology.
Gurgling space
Andrey Dmitrievich, in what part of the many-sided Universe are we, earthlings, "registered"?
- Depending on where we got to. The Universe can be divided into large regions, each of which in all its properties looks - locally - like a huge Universe. Each of them is enormous. If we live in one of them, then we will not know that other parts of the universe exist.
Are the laws of physics the same everywhere?
- I think different. That is, in reality, the law of physics can be the same. It is just like water, which can be liquid, gaseous and solid. However, fish can only live in liquid water. We are in a different environment. But not because there are no other parts of the Universe, but because we can live only in a convenient segment of the “many-sided Universe”.
What does this segment of ours look like?
- On the bubble.
It turns out that people, in your opinion, when they appeared, were all sitting in one bubble?
- Nobody has been in prison yet. People were born later, after the end of inflation. Then the energy, which was responsible for the rapid expansion of the Universe, passed into the energy of ordinary elementary particles. This happened due to the fact that the Universe boiled, bubbles appeared, as in a boiling kettle. Bubbles hit each other from the shadows, released their energy, and due to the release of energy, normal particles were born. The universe has become hot. And after that, people arose. They looked around and said, "Oh, what a big universe!"
Can we get from one bubble universe to another?
- In theory, yes. But on the way we will come across a barrier. This will be a domain wall, energetically very large. To fly to the wall, you have to be a long-liver, because the distance to it is about 10 millionth light years. And in order to cross the border, we need to have a lot of energy in order to properly accelerate and jump over it. Although it is likely that we will die right there, because particles of our, terrestrial type can decay in another universe. Or change your properties.
Do bubbles-universes appear all the time?
- This is an eternal process. The universe will never end. In different parts of it there are different pieces of the Universe, of different types. It happens like this. Two bubbles appear, for example. Each of them expands very quickly, but the universe between them continues to swell, so the distance between the bubbles remains very large, and they almost never collide. More bubbles appear - and the universe expands even more. Some of these bubbles do not have any structure - they have not formed. And in the other part of these bubbles galaxies arose, in one of which we live. And there are such different types of the Universe - about 10 to the thousandth power or 10 to the hundredth. Scientists are still counting.
What happens in these many copies of the same universe?
- The universe has now entered a new stage of inflation, but very slow. This will not touch our Galaxy yet. Because the matter inside our Galaxy is gravitationally very strongly attracted to each other. And other galaxies will fly away from us, and we will not see them again.
Where will they go?
- To the so-called horizon of the world, which is 13.7 billion light years away from us. All these galaxies will stick to the horizon and melt away for us, become flat. They will no longer come with ignorance from them, and our Galaxy alone will remain. But this is not for long. Over time, the energy resources in our Galaxy will gradually run out, and a sad fate will befall us.
When will this happen?
- Fortunately, we will not break up soon. In 20 billion years, or even more. But due to the fact that the universe is self-healing, due to the fact that it produces more and more new parts in all its possible combinations, the universe as a whole and life in general will never disappear.