What was our universe before the Big Bang?

Theoretical Physicists and cosmologists are searching for answers to the fundamental questions: "Why are we here?" "When did the universe?" and "How did this happen?" However, despite the obvious importance of finding answers to these questions, there is the issue that overshadows them all with interest: "What was before the Big Bang?".

To be honest: we can't answer this question. No one else can. But no one stops to speculate on this topic and consider a few interesting assumptions? Agree with this, for example, Sean Carroll of the California Institute of technology. Last month Carroll was involved in passing twice a year meeting of the American astronomical society, where he offered several "pre-explosive" scenarios, whose "final chord" could be the emergence of our Universe. Again, this is just speculation, not theory, so please take this into account.

"At that time, if I may say so, has not acted with the laws of physics as we know them, because then they have not existed" — says Carroll.

"When physicists say that have no idea what was going on, they say it in all seriousness. This period of history is absolutely impenetrable darkness", — agrees Peter Voight, a theoretical physicist at Columbia University.

One of the strangest properties of our Universe is that it has a very low level of entropy. This term has many interpretations, but in this case we are talking about degree of disorder. With the Universe the order it has more than clutter. Imagine a bomb filled with sand. The bomb explodes, and it contained billions of billions of sand grains scatter in different directions – in front of you is essentially the layout of the Big Bang.

"Only instead of the expected chaotic scattering those grains of sand that represent the fabric of our Universe, immediately turned into many ready-made "sand castles", formed it is unclear how and unaided", — says Stefan countryman, graduate student, Columbia University.

The Result of the Big Bang could (and perhaps should) lead to a high level of entropy of the mass in the form of unevenly distributed matter. Instead, we see star systems, galaxies and entire galaxy clusters. We see the order.

In Addition, it is important to understand that entropy, or disorder, over time, can only increase – the same sand castle, sooner or later, and without help will again fall apart into many grains. Moreover, as pointed out by Carroll, our observation of time is directly correlated with the level of entropy with the appearance of the Universe. While the entropy can be regarded as a kind of gramasevaka physical property that has only one direction – into the future.

So, the entropy according to the laws of physics, can only increase, however, the current level in the Universe is very low. According to Carroll, this can only mean one thing: the early universe had had even less level, that is, the universe had to be even more organized and orderly. And this, in turn, could push the idea of what was actually our Universe to the Big Bang.

"There are many people who believe that the early universe was very simple, uninteresting and bland system. However, as soon as you connect to this question is entropy, the perspective then changes and you realize that in this case, there are things that need to explain" — continues Carroll.

Even If you put aside the entropy, then we'll stay and other important aspects that you must somehow adjust to our present Universe in which we live. Moreover, in some cases, a low level of entropy seems to be less important than others. Therefore try to consider the three most popular assumptions about what could happen to the Universe before the Big Bang.

the

Model of the "Big bounce"

According to one hypothesis, the low entropy of our Universe is associated with the fact that her appearance itself was the result of the collapse of a "previous" Universe. This hypothesis States that our universe could have formed as a result of rapid compression ("rebound"), managed by the complex effects of quantum gravity (the singularity), in turn, gave rise to the Big Bang. In turn, this suggests that we with the same success can live in any point of the infinite sequence of Universes arising and, on the contrary, in the "first iteration" of the Universe.

This hypothetical model of the Universe is sometimes called the model the "Big bounce." The first mention of the term sounds even in the 60s, but more or less formed the hypothesis of this model has become only the 80's-early 90-ies.

Among the less important controversial issues, the model of the "Big bounce", there are clear disadvantages. For example, the idea of a collapse to a singularity contradicts the General theory of relativity – the rules according to which gravity works. Physicists believe that the effect of a singularity can exist inside black holes, however, the known physical laws may not provide us a mechanism to explain why the "other universe", reaching the singularity should create the Big Bang.

"In General relativity theory there is nothing that would indicate «rebound» new Universe in a singularity", — says Sean Carroll.

However, this is not the only big controversial moment. The fact that the model of the "Big bounce" implies a straightforward time with decreasing entropy, but, as mentioned above, entropy will only grow over time. In other words, according to the known laws of physics, the appearance of the Bouncing Universe is impossible.

Further development of the model led to the emergence of the hypothesis that the time in the Universe may be cyclic. But the model is still not able to explain how the ongoing expansion of the Universe will change its compression. And yet this does not necessarily mean that the model of the "Big bounce" is completely wrong. It is possible that our current theories about it is just flawed and not fully thought out. In the end, physical laws that we have now, were withdrawn subject to the limit under which we are able to observe the Universe.

the

the Model of "Sleeping" of the Universe

"Perhaps before the Big Bang, the universe was a very compact, slowly evolving static space" — theorize physicists such as Kurt Hinterbichler, Austin Joyce and Justin Khoury.

This "predstava" the universe had to have a metastable state, i.e. to be stable up to the moment until a more stable state. By analogy, imagine a cliff, on the edge of which is in a state of vibration is a boulder. Any touch to the boulder leads to the fact that he falls into the pit or — which is closer to our case – before the Big Bang happens. According to some theories "predstava" the universe could exist in a different form, for example in the form of a flattened and very dense space. In the end, this metastable period came to an end: she has dramatically expanded and took the form and condition of what we see now.

"In the model of "sleeping" of the Universe, however, also have their problems" — says Carroll.

"It also suggests that our Universe is the appearance of a low level of entropy and thus does not explain why this is so."

However, Hinterbichler, a theoretical physicist from the University of Case Western Reserve, does not consider the emergence of low-level entropy problem.

"We're just looking for the explanation of the dynamics that took place before the Big Bang, which explains why we see what we see now. While this is only the only one we got", — says, Hinterbichler.

Carroll, however, believes that there is another theory "preexplosive" of the Universe, which can explain the low level of entropy present in our Universe.

the

a model of the "Multiverse"

the Emergence of new universes from the "parent Universe"

A Hypothetical model of the Multiverse avoids the ambiguity associated with a decrease in entropy, as in the case with the model of the "Big bounce", and gives an explanation of its low level, says Carroll. It originates from the idea of "inflation" — well accepted but incomplete model of the Universe. The term "inflation" and the first explanation of this model was proposed in 1981 year by physicist Alan Gut, currently working at the Massachusetts Institute of technology. According to this model, the space after the Big Bang expanded dramatically. So dramatically that the rate of expansion was higher than the speed of light. According to quantum mechanics, in space there are accidental, barely visible energy fluctuations. At some point the inflationary period, the peaks of these oscillations peaked and caused the emergence of galaxies, voids and nizkorentabelnyh large-scale structures that we observe today in the Universe.

Very inflationary model was developed on the basis of observations of the relic cosmic microwave radiation – the oldest type of radiation that appeared after only a few hundred thousand years after the Big Bang. Scientists believe that the inflationary model perfectly predicts its existence.

According to one of the assumptions, the multiverse can be results...