Francisco Jose Soler Gil from Seville University and Manuel Alfonseca of the Autonomous University of Madrid (both Spain) considered two of the most popular variants of the concept of an infinite Universe in which history repeats itself an infinite number of times in various far-spaced points of space.

According to some modern interpretations of quantum mechanics, any dimension at the micro level leads to an alternate universe, and sometimes more. (Illustration Stephen Whitt.)

One of the concepts it is based on classical cosmology, the other on quantum mechanics. Unite their General conclusions: if you take yourself and change something in yourself (take the red shirt and wear the same, but the blue), then there will be another along. Wear purple - and this is the third you. Somewhere in space there is someone like you in any of these shirts, but with one small difference. Even if you change the drink in their hands from coffee to tea, you will ensure the existence of yet another version of yourself somewhere at an enormous distance. And the thing is, clearly, not only in you, the universe also has a substantial number of copies. More precisely, an infinitely large number of copies - though the differences between most of them are very insignificant - like, say, the color of the shirt of one of its inhabitants at one point of time. Most of these Universes do not differ from each other. In other words, if you remove the red shirt and put on a blue or nothing to do will not, and these options are duplicated somewhere infinite number of times. You do not own such a concept? You are not alone.

The roots of these concepts is quite ancient and go in the first slim theoretical views of mankind. However, in modern cosmology them again seen as a relatively reliable ways of the device of the world. Spanish researchers have wondered whether such views are really to be derived from known physical laws, in particular from the classical relativistic physics.

It was found that if the concept of infinite alternate histories of the Universe, it will turn out that this situation has a number of unexplained consequences. As the authors state, if the probability of DNA-life different from zero (which, of course, because life on Earth seems to exist), then, accordingly, the number of possible sets of genes are limited. With an infinite number of alternate Universes this implies an infinite set of identical genotypes in different districts of the Universe.

Endless stories a finite number of living beings means that there are an infinite number of times not just Universes, differing only in color shirt on you, but Universes, anything from each other not different, including the proverbial shirt.

However, in this scenario there are counter-arguments, say the authors. First: we cannot be sure that the likelihood of DNA-life different from zero. Even if we except the Earth, identify even billions of planets with the DNA of life, from this logically will not follow a non-zero probability of occurrence of such a life.

Why? As explained by the Spaniards, if DNA-life in the history of the Universe unit (Earth), then the probability of its occurrence is equal to one, divided into positive infinity. In other words, equal to zero. Worse, even if known to us the life there were many quadrillion times (here you can substitute any how pleasing large number), and then the probability of its occurrence is zero - unless, of course, the number of cases of the Universe is indeed infinite.

"If we have an infinite number of possible stories, the fact that we have our known history (or a limited number of [similar]), leading to the emergence of life, does not make this story likely: it would be equal to one divided by infinity, that is, zero - emphasizes Mr. Alfonseca. - To have the possibility of life is greater than zero, we need to have an infinitely large number of approaches". There is some contradiction, making version endless stories in the framework of classical cosmology difficult to prove. As the authors conclude, there is thus no way to bring the script from the known physical laws. Even if it is correct, to confirm it, based on our current knowledge, it is impossible that displays the proof of this theory beyond the science in its modern form.

Another similar approach - version Jaume Garriga (Jaume Garriga) and Alexander Vilenkin. The number of stories in it are limited. And it is based on the idea that originate from quantum theory: a discrete space regions have limited amounts of energy. In the interpretation of quantum mechanics, postulates dekogerentsiya history, infinite universe (about infinity alternative Universes) can be divided into an infinite number of regions, cannot affect each other, as they divided the event horizon. In this situation Garriga and Vilenkin believe that the number of possible histories of each region and of course, according to quantum mechanics, the energy in them is divided into quanta. The result: an infinite number of such separate regions of space-time plus a finite number of possible stories in each of these regions means that each story is still ultimately will be repeated an infinite number of times.

Soler Gil and Manuel Alfonseca criticized almost all of the postulates underlying version Garriga and vilenkina. First, the quantum theory as applied to cosmology still rather hypothesis without proper verification, rather than Vice versa (note that advocates of this theory argue the exact opposite).

Secondly, the expansion of the Universe and gravitational effects of black holes in it can increase the number of possible histories to infinity. In this case, the numerator of possible stories will be infinity. So, the repetition of any of the stories will be unlikely, not to say impossible. Note that this version of Spanish theorists looks impressive sound, and even in the framework of the quantum-mechanical ideas to respond to the challenge.

However, most critics have received the premise of endless number of regions in the Universe. As noted by the Spaniards in the past many times there were situations when infinity in physical theories seemed inevitable, and yet each time with the next step in the development of physics was possible to eliminate this infinity.

Today in classical cosmology infinity postulated in the singularity of the black holes and singularities of the Universe before the Big Bang. In quantum mechanics infinity threaten the vacuum energy and certain parts of quantum field theory. As the authors hope that this might both theory is only an approximation of the third, more General, which will eliminate the need for infinite values, allowing were said to Paul Dirac, "get rid of"infinity.

Summing up, Soler Gil and Manuel Alfonseca note that they cannot refute the means available conclusions about the endless repetition of the Universe. But not from lack of physical reasoning, and from the fact that the idea of the infinite repetition of the history of the Universe lies in the sphere of philosophy, mythology and NF, and not modern cosmology, which provides no strict grounds to assume infinity stories of the Universe and their endless repetition.

With a Preprint of the relevant survey can be found here.

Based on the materials Phys.Org.