Translartion. Region: Russians Fedetion –
Source: Novosibirsk State University – Novosibirsk State University –
As part of the popular science marathon “Darwin Week”, this year the dean Faculty of Physics, Novosibirsk State University, Doctor of Physical and Mathematical Sciences Vladimir Blinov gave a lecture on how people’s ideas about the origin and structure of the Universe have changed and what role relic radiation plays in this.
“My lecture is a story about how humanity tried to understand the structure of the world in which it lives. And I will tell you how the history of the Universe appears in the light of relic radiation,” he began his speech.
People have been trying to understand how the Universe works and to build a model of it for quite some time. Even before our era, in ancient Alexandria, the scholar and scribe Claudius Ptolemy wrote an encyclopedia of astronomical and mathematical knowledge of the ancient Greek world, known today as the Almagest. In his picture, the center of the universe was a flat Earth, around which the Sun, planets, and fixed stars were located.
Interestingly, at about the same time, another scientist from Alexandria, Eratosthenes, used mathematics to prove that the Earth is spherical and even calculated its approximate dimensions. True, he was wrong in his calculations by about 10%, but given the imperfection of his instruments, this was excusable. However, it was Ptolemy’s concept that became officially recognized for a long time.
After about one and a half thousand years, Renaissance scientists finally debunked it, and through the efforts of Nicolaus Copernicus, Tycho Brahe, Johannes Kepler and Isaac Newton, the model of a heliocentric solar system and a universe based on the laws of classical mechanics was established in science.
— This state of affairs lasted for about 300 years, and during this time, data gradually accumulated that could not be explained from the standpoint of classical Newtonian mechanics. And then Einstein appeared, who created the Special and General Theories of Relativity and, on their basis, created a model of the Universe, — Vladimir Blinov continued.
This model no longer operated with classical mechanics, but with relativistic mechanics. And one of the first predictions of the General Theory of Relativity was the explanation of the anomalous precession of the orbit of the planet Mercury.
And a few decades later, the American astronomer Hubble established that the Universe is expanding. Then, physicists, relying on the results obtained by Hubble, abandoned the stationary model of the Universe (from which, by the way, Einstein also proceeded) and came to the conclusion that it used to be more compact, hotter, and approximately 13.8 billion years ago its expansion began. Simply put, this is how the cosmological concept, better known as the Big Bang Theory, was born.
By the way, the age of the Universe determines the radius of the part of the Universe visible to us due to the finiteness of the speed of light.
— But this gives scientists a huge bonus: the further away from us the observed object is, the younger we see it. Therefore, thanks to the development of telescopes, astrophysicists and cosmologists can see and study the history of the Universe with their own eyes, rather than reconstructing it from indirect data, — Vladimir Blinov emphasized.
He then briefly described the various stages of the history of the Universe, starting from the time when it was in a state of helium-hydrogen plasma. It was the recombination of this plasma, according to astrophysicists, that led to the appearance of individual atoms, from which stars and other structures in the Universe were later formed. The consequence of this, in particular, according to scientists’ calculations, was the emergence of radiation with a high degree of isotropy and a spectrum characteristic of an absolutely black body with a temperature of 2.73 K. Soviet astrophysicist I.S. Shklovsky designated it with the term “relict radiation”.
At first it was a theory, but in 1965, astronomers Arno Penzias and Robert Wilson of Bell Telephone Laboratories, while investigating the effects of cosmic radiation on radar, discovered that the antenna had an excess noise temperature of 3.5 K, which they could not explain. It was only after consulting with physicists at Princeton University, who had been trying to detect the relic radiation for a year, that it became clear that this was it.
— This became proof that the Big Bang model works, that at the age of 380 thousand years the Universe consisted of plasma with a temperature of 3000 K and this radiation is the noise of that same plasma. But further observations began to give rise to new questions, — the dean of the Physics Department emphasized.
In particular, why is this temperature the same at different, distant points in the Universe, which could not contact each other at that time. There were other inconsistencies. They were explained using the inflationary model of the expansion of the Universe, to the creation of which Soviet physicists Andrei Starobinsky, Andrei Linde and their American colleague Alan Guth contributed.
In its framework, the expansion of space occurred as a result of quantum fluctuations of a scalar field similar to the field proposed by Higgs, whose quantum, the Higgs boson, was discovered in 2021 at the Large Hadron Collider, and it was almost instantaneous and led to the formation of many “bubble” universes. Precise calculations showed that the sizes of these bubble universes were many orders of magnitude larger than the visible radius of our Universe. For this reason, we do not observe “walls” separating these “bubble” universes.
— This is how the concept of the Multiverse was born, in which an infinite number of Universes with different properties were, are, and will be formed. Some of them quickly collapse, some do not. We live in one of these universes, — the speaker concluded.
And since the number of universes is infinite, and the number of particles in them is finite, all possible scenarios of their composition and evolution are realized. Even exact copies of our Universe are possible, and perhaps somewhere at this time the same lecture is being given by Vladimir Blinov’s double.
Please note: This information is raw content directly from the source of the information. It is exactly what the source states and does not reflect the position of MIL-OSI or its clients.