According to a recent theory by Russian scientists, there is no dark energy in a universe with boundaries. But then what is beyond the cosmos and how might the edge of the end of the universe look like under such conditions?
For a long time it was believed that outer space is filled with ordinary matter – stars, planets, asteroids, comets and highly rarefied intergalactic gas. However, in this case, the accelerated expansion discovered in the 20th century contradicts the law of gravity, according to which bodies are attracted to each other. Gravitational forces would slow down the expansion of the Universe, but would not speed it up in any way.
Then a hypothesis arose that the Universe is mostly filled not with ordinary matter, but with some kind of “dark energy”, which has special properties. It is believed that it has negative pressure. However, no one knows what it is and how it works, but, according to one theory, 70% of the Universe consists of this dark energy.
Despite the fact that there are disputes about its presence, some theories of the end of the Universe directly or indirectly affect the idea of the existence of such matter.
We offer for acquaintance both scientific theories that are opposite on this issue, and that do not affect it at all, striving to answer the question as rationally as possible: does our Universe have an end or not?
The universe is not without end, but will expand
According to the hypothesis put forward by scientists from the Immanuel Kant Baltic Federal University, located in Kaliningrad, the Universe has boundaries, but at the same time, it lacks the same dark energy that was mentioned above.
However, this theory, although it “holds back” the entire cosmos within certain limits, does not give an exact answer of what the end of the Universe looks like, subject to its continued expansion.
“The fact that our Universe is expanding was discovered almost a hundred years ago, but how exactly this happens, scientists realized only in the 90s of the last century, when powerful telescopes (including orbital ones) appeared and the era of precise cosmology began.
In the course of observations and analysis of the data obtained, it turned out that the Universe is not just expanding, but expanding with acceleration, which began three to four billion years after the birth of the Universe, ”the scientific material says. Domestic experts are convinced that it is the acceleration of expansion that is the marker by which one can understand the existence of a limit to the universe.
Their hypothesis is based on the fact that instead of dark energy, the Universe has an effect similar to the Casimir effect, if we imagine that the Universe has an end, possible boundaries in the form of some kind of walls. It is on these walls that the effect extends.
The Casimir effect is the mutual attraction of conducting uncharged bodies (for example, plates close to each other) under the action of quantum fluctuations in a vacuum. Roughly speaking, we are talking about vacuum fluctuations due to the creation and disappearance of virtual particles in it.
The closer the bodies are, the more actively the production of particles between them is suppressed. As a result, the pressure between the bodies becomes less than the pressure on them from the outside, where the birth of photons is not limited by anything. This is how attraction works.
A similar effect, according to scientists from Kaliningrad, is also observed in the Universe – between its boundaries, on the reverse side of which the described particle pressure is absent. The pressure on the borders from our side, that is, from the inside, makes the Universe expand with acceleration.
Soap bubble that can burst
A concept quite close to that of the Baltic scientists is offered by their colleague from the University of California, Andreas Albrecht. He also believes that the end of the universe exists, despite its continued expansion. However, Albrecht belongs to that wing of scientists who tend to think that the expansion will eventually stop.
In addition, in his works, he expresses the opinion that, having reached its maximum, the final Universe will be slightly larger than the space we see now. In numerical terms, this is only 20% of the current state. And the foreign specialist does not refuse hypothetical dark energy in his own conclusions.
For the accessibility of his theory, he proposes to depict the Universe as a soap bubble, which always has a finite size. However, being a scientist, Albrecht does not dare to name where the end of the universe is and what is further beyond its borders, rightly operating on the lack of data.
Wave theory of the end of the universe
It is difficult to blame Albrecht for the lack of data. This is explained by such a property of the cosmos as the cosmic background radiation formed with the very first atoms, according to the Big Bang theory.
It does not allow scientists to study distant galaxies and their stars, being a natural barrier in their development and an opportunity to look beyond the edge of the end of the Universe, if it exists, of course.
But at the same time, relic radiation allows specialists to consider the wave spectrum of space. Research in this area led scientists to the hypothesis that if the Universe is truly infinite, then it must contain waves of a wide variety of wavelengths.
However, in its nine years of operation, the WMAP, launched by NASA, just to study the cosmic microwave background radiation, did not detect any large waves. It turned out that outer space has a narrow spectrum of waves, which means that the end of the universe exists.
So far, however, astrophysicists have not been able to determine the exact shape and boundaries of the universe. However, all the same waves in space, or rather their vibrations, can help to explore this.
Thanks to their various types that arise in space, it is possible to determine what is at the end of the Universe, what shape it is and what boundaries it has. It remains only to wait, because such studies often last for years.