General, Research, Technology

Can the universe exist forever?

13.8 billion years ago the universe representeda singularity - a space infinitely compressed by high pressure. However, in less than one fraction of a billionth of a second, this tiny dot has expanded to incredible sizes. The classical history of our universe has a beginning, middle and end. So, according to the general theory of relativity (GR) by Albert Einstein, over time, the expansion of the universe should slow down. However, reality paints a completely different picture: the Universe continues to expand faster and faster. The reason for this discrepancy, scientists consider the mysterious dark energy, but it is possible that our understanding of the universe and its evolution must be reviewed.

There are many assumptions about how our universe originated and why.

Content

  • 1 How did it all begin and could it be otherwise?
  • 2 What if the Big Bang really wasn't?
  • 3 Big Bounce: Can the Universe Expand Infinitely?
  • 4 Search for answers: all paths lead to dark energy

How did it all begin and could it be otherwise?

The universe began to expand immediately after the Bigthe explosion. The rate of expansion at an early stage of its evolution - this process is called cosmological inflation - was significantly greater than after inflation ended. So, gradually the Universe expanded and cooled, but only with a fraction of the initial speed. Over the next 380,000 years, the universe was so dense that space was an opaque, super-hot plasma of scattered particles. When the Universe cooled sufficiently to form the first hydrogen atoms, it became transparent for the passage of light. Then the radiation flashed in all directions and the Universe was on the path to becoming what we see it today - an empty space that alternates with clumps of gas and dust, stars, galaxies, black holes and other forms of matter and energy. In the end, according to some models, all the clots of matter will disperse so far apart that they will gradually disappear. The universe will become a cold, homogeneous soup of isolated photons. But what if the Big Bang was not the beginning of all this?

The Big Bang Theory is so widely accepted thatsometimes you can forget that this is only a theory in which there are flaws. For this reason, scientists offer a variety of scenarios. Thus, it was speculated that the Big Bang was probably more of a “Big Bounce” - a kind of turning point in the ongoing cycle of contraction and expansion of the universe. Another assumption is that the Big Bang became a reflection point when the mirror image of our Universe expands beyond the “other side”, in which antimatter replaces matter, and time itself flows in the opposite direction. According to the third assumption, the Big Bang is a transition point in the Universe that has always existed and will continue to expand indefinitely. All of these theories are outside the scope of basic cosmology, but all of them have found support among respected scientists. The growing number of new theories competing with each other suggests that perhaps the time has come to reconsider the fact that the Big Bang marks the beginning of space and time.

The universe that we currently see consists of clusters of gas and dust, stars, black holes and galaxies

What if the Big Bang didn't really happen?

In academic circles, the idea has been expressed more than oncethat the Big Bang ... wasn’t. So, Eric Lerner, the author of the book of the same name, which he wrote back in 1992, presented the results of a study according to which, according to Invers, there is a mismatch between the Big Bang theory and observable evidence. “For the development of cosmology, it is necessary to abandon the main hypothesis of the Big Bang,” the Lerner statement said. "The real crisis in cosmology is that there has never been a Big Bang."

It's about evidence inconsistencythe presence of lithium in space, which astronomers, according to Lerner, have long been aware of. Today, scientists believe that the exact amount of helium, deuterium and lithium was obtained as a result of fusion reactions in a dense, very hot cloud of chemical elements that appeared after the Big Bang. However, Lerner, who spent decades observing such reactions in detail, says that the results of him and other scientists do not coincide with long-standing theories based on observations of older stars. He found that in old stars, less than half of helium and less than one tenth of lithium are observed, than predicted by the Big Bang nucleosynthesis theory, according to which a quarter of the entire mass of the Universe consists of helium. Lerner is convinced that neither lithium nor helium were created before the appearance of the first stars in our galaxy.

Could our universe come from nothing?

However, not all scientists agree with the theoryLerner. According to the professor of astronomy from the University of Southern California, Vae Perumian, Lerner rarely refers to peer-reviewed articles, and many of his arguments do not hold water. So, Perumian believes that microwave cosmic background radiation (or relic radiation), which indicates radiation emanating from the Big Bang, is a pillar of the cosmological theory, which Lerner cannot challenge. Furthermore, if there were such serious flaws in the Big Bang theory, Lerner would not be the only critic of this theory.

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But Lerner is not alone. Nobel laureate cosmologist James Peebles believes that it is necessary to stop calling the earliest moments of our universe the “Big Bang”. As France Presse reports, Peebles believes that there is no good way to check whether an event like the Big Bang really took place - cosmologists have evidence of rapid expansion outside, but there is nothing more discrete than the singular point that exploded to create everything in The universe. Peebles has no alternative to the Big Bang theory, and he is convinced that without sufficient data, scientists should not assume that this convenient hypothesis is true. At the same time, the scientist admits that in the absence of a better way to describe the beginning of the Universe, the Big Bang works great. In his calculations, Peebles also adheres to the generally accepted theory, although he really does not like it.

Big Bounce: Can the Universe Expand Infinitely?

Most common in academiaThe Big Bounce hypothesis originates in dissatisfaction with the idea of ​​cosmological inflation. Cosmic microwave background radiation is a fundamental factor in every model of the Universe since it was first discovered in 1965. Moreover, relict radiation is the main source of information about what the early Universe looked like and at the same time a mystery to physicists. The fact is that the relict radiation looks the same even in regions that, it would seem, could never interact with each other in the entire history of the Universe.

The scars left by the Big Bang in faint relict radiation that permeates the entire cosmos give clues about what the early Universe looked like.

According to the Big Bounce hypothesis, the universewill expand until it breaks up to one infinitesimal point - this is a cycle that lasts forever. In 2007, Martin Bojawald, a physicist at the University of Pennsylvania, based on Einstein’s model, put forward the theory of loop quantum gravity, a field of quantum physics that describes the extremely high energies that dominated the early Universe, so researchers concluded that the Universe did not come from and will not expand indefinitely. However, a study by Bozawald shows that the hypothetical previous Universe was not exactly the same as ours. By and large, the Big Bounce hypothesis is consistent with the Big Bang picture of a hot, dense universe that originated 13.8 billion years ago, which began to expand and cool. But instead of becoming the beginning of space and time, the big bang turned out to be the moment of the transition of the Universe from an earlier phase of existence, during which space was reduced.

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However, critics believe that there is littleevidence to support this theory. So, Peter Voight, a mathematician at Columbia University, wrote on his blog Not Even Wrong: “In order to be considered a legitimate theory, such claims must be supported by evidence.”

Search for answers: all paths lead to dark energy

Based on the fact that the theory of the Big Bang is the generally accepted theory of the appearance and evolution of the Universe, scientists are trying to find an answer to the question of why the Universe expands with acceleration.

Dark matter and dark energy are probably the key to understanding our universe

As the researchers analyzedthe movement of stars and galaxies, they concluded that there were invisible particles, which they called dark matter. And the constant acceleration of the expansion of the Universe (Hubble constant), suggested that it was caused by a phenomenon that researchers called dark energy. Dark energy and dark matter are the main scientific mysteries of our time, therefore, researchers of the international group for the study of dark energy (DES) are looking for answers. DES started work in 2004, now 400 scientists from 26 different research institutes from seven countries are participating in the project. Scientists are searching for dark energy using the most sensitive astronomical digital camera with a resolution of 570 megapixels. The camera is mounted on the Viktor Blanco telescope at the Cerro Toledo Observatory in the Chilean Andes. This is a kind of scalpel equipped with five lenses.

Answers to fundamental questions about howthe Universe has appeared and what is dark matter and dark energy, the researchers believe, should be presented to the general public in about five years. DES's goal is to analyze 100,000 galaxies that are up to 8 billion light-years from us. Since dark energy cannot be seen, researchers measure the Hubble constant to determine exactly if dark energy exists and what it consists of. One way or another, we can only wait for the results of the work of an international team of scientists and build assumptions about what our Universe is like.