the «Copernicus – Bruno principle». For the church fathers, multiple world’s concept was an attribute of pagan beliefs. After the publication of the Bruno’s Inquisition case, it became known that his biggest «heresy» was the idea of multiple inhabited worlds in the Universe. However, some authorities of the Catholic Church also expressed similar ideas. For example, Thomas Aquinas, the theology founder, wrote that the world in which we live is not the only possible one. Hercules Cyrano de Bergerac, Fontanel, Bernard le Bevier de Fontanelle, Christiaan Huygens, Voltaire, Immanuel Kant, Pierre-Simon de Laplace, and William Herschel dedicated their works to this issue, though they were the speculative ones. Camille Nicolas Flammarion wrote in his works «La plurality des Mendes Habits» (Numerous inhabited worlds, 1862), «Les Mendes imaginaries et les modes reels» (Imaginary worlds and real worlds, 1865), «Les Etoiles et les curiosities du ceil» («Starry Sky and Its Miracles») (1881) and others that there is a dynamic principle in space, invisible and intangible, dispersed throughout the Universe, independent of the visible and weighty matter and influencing it. And the intelligence superior to our one is in this dynamic element.
Konstantin Tsiolkovsky expressed similar ideas in his works «Cause of the Cosmos», «Will of the Universe», «Unknown Intelligent forces», «Monism of the Universe», «Scientific Ethics». In a philosophical note «Planets Inhabited by the Living Beings,» he wrote the following: «In the known Universe, one can count a million billion suns. Therefore, we have the same number of planets similar to Earth. It is inconceivable to deny the life’s availability on them. If it has occurred on Earth, why can’t occur it under the same conditions on planets similar to Earth? Their number may be less than the number of suns, but still they should be. It is possible to deny life on 50, 70, 90% of these planets, but it is absolutely impossible to deny live of all of them».
Winston Churchill, a famous politician, wrote an essay entitled «Are We Alone in the Universe?» in which, on the grounds of the «Copernicus principle», he stated that the Universe is too vast for the life on Earth to be unique. He determined that reproduction is the necessary condition for life, and the presence of water, appropriate temperature and gravity to form the atmosphere stand for significant factors. Based on these assumptions, Churchil believed that, speaking of the Solar system, the life could have occurred only on Mars and Venus in addition to Earth.
Hugh Everett, an American physicist, put forward a theory of parallel worlds in the mid of the XX century. His article on Physics titled «Formulation of quantum mechanics through «related states» was published in the journal «Reviews of Modern Physics» (1957, v. 29, № 3, p. 454-462). The author’s multi-world interpretation (The Many-Worlds Interpretation of Quantum Mechanics) suggested the «parallel universes» existence, in each of which the same laws of nature function and which are characterized by the same world constants, but which are in different states.
Hugh Everett suggested that the Copernicus’s Universe is only one of the universes, and it is the physical multitude that is the basis of the Universe. In his opinion, the «perceived reality» is a multitude of classical realizations of physical worlds, built on the basis of rationally conscious worlds that reflect the interaction of the Observer with a single quantum reality.
According to the H. Everett’s concept, the Object and the Observer’s quantum-mechanical interaction leads to the formation of a set of different worlds, and the number of branches equals to the number of physically possible outcomes of this interaction. And all these worlds are real. Hugh Everett called the multidimensional interpretation of quantum mechanics the «state relativity». In his opinion, this theory perfectly explained the mysteries of quantum mechanics, which caused fierce debate among scientists at that time.
Hugh Everett’s theory is sometimes mistaken for the parallel worlds’ theory. However, it does not imply the real existence of other worlds, but only one really existing world, which is described by a single wave function, which, while measuring a quantum event, must be divided into an observer (conducting a measurement) and an object, each being described by its own wave function. On the contrary, the Copenhagen interpretation places the observer in his classical world, which is different from the quantum world of the object observed.
The main reason for rejecting the Everett’s ideas recognition is the assertion that they are «experimentally unprovable». In addition, scientists using this interpretation cannot explain the nature of the boundary between the quantum and classical worlds. This theory explains a number of phenomena only at the micro-level, and it does not agree with the laws of preservation of mass, energy, momentum, etc. at the macro-level of our existence.
Modern Physics, based on a multi-world interpretation of quantum mechanics, superstring theory, multiuniverse theory, implies the multiple worlds’ existence. According to the theoretical physicists estimates adhering to the theory of superstrings, parallel worlds can be from ten raised to one hundredth power to ten raised to five hundredth power. Today the «many-world interpretation» is called the Oxford interpretation of quantum mechanics, which is one of the leading ones along with the Copenhagen one.
Experts do not exclude the possibility that the other worlds’ representatives of live somewhere in the depths of the vast universe. Physicists of Stanford University have been able to establish a hypothetical number of universes formed as a result of the Big Bang. Moreover, it is possible that they can be included into each other and inside our Earth as well. Perhaps there is a hidden Earth-2. They also estimated the amount of information that such a number of the parallel worlds’ existence carries, and came to the conclusion that a person is not able to observe all the universes, since the structural features of his brain are not able to perceive more than ten raised to the sixteenth power bits of information during his lifespan.
Frank Donald Drake, a professor of astronomy and astrophysics at the University of California, has developed a formula that, in his opinion, determines the number of extraterrestrial civilizations. The formula named after him consists of seven constituent elements: the number of stars formed during the year; fraction of stars representing planets; the number of planets or their satellites with livable conditions; the probability of the life’s occurrence, the probability of turning it into an intelligent one; fraction of planets with highly developed creatures; lifetime of a civilization that lives on the planet. Depending on the choice of parameters, the Drake formula gives grounds to believe that there are from 10 to 100 extraterrestrial civilizations in the galaxy at each separate moment.
However, repeatedly performed calculations with the Drake’s formula being used gave a different number: from their complete absence up to 5 thousand. Such a dispersion arose due to the fact that the researchers evaluated the values of the parameters included in the formula in different ways. Critics note that the Drake’s formula does not take into account the time variation of the parameters included in the formula. At the current level of the scientific development, only two coefficients for this formula can be relatively accurately determined, while others cannot be determined at all.
Brian Lacki, an astrophysicist at the Institute for Advanced Study showed that depending on the combination of parameters necessary for the intelligent life’s occurrence, the probability of its existence in the world ranges from 1.4 up to 48%. He mentioned the type and mass of the planet, the distance between it and the star, as well as the variety of genetic material for the various life forms’ occurrence among the factors determining the appearance of civilization.
Adam Frank, a professor of Physics and Astronomy from the University of Rochester and his colleagues from the University of Washington’s astronomy and astrobiology department, by means of the Drake’s formula, calculated not the estimated number of intelligent civilizations, but rather the probability that human civilization is the only one intelligent in the Universe. It turned out that this probability is less than one divided by 10 raised to the 22nd power. Their further calculations showed that there are approximately 10 billion intelligent civilizations in the Universe. There are several thousands of them only in our galaxy, in the Milky Way. Many of them died, but it is possible that several hundreds of high-level civilizations still survive in our galaxy. In their
