The Big Bang is usually considered the beginning of everything that is today: about 13.8 billion years ago, the observed universe began to grow and develop. But what was all this before the Big Bang? What was and was there at all? On this score, there are many theories, each of which has its own scientific basis.
The first thing to understand is what the Big Bang really is. It is possible that the universe at the time of the Big Bang was tiny, Carroll continues. Well, seriously, there is no way to look back in time at things that we are not able to discern even today. All we really know, or rather, we want to believe we know, is that the universe at that moment was very dense, peach-sized or less, and a temperature of over four billion degrees Celsius. Then it began to lose density very quickly. As a consequence of this theory, there really is nothing outside of the Universe, because the Universe, by definition of scientists, is everything.
It is believed that before the first second after the Big Bang, when the Universe has cooled down enough for protons and neutrons to collide and stick together properly, it went through a process of exponential expansion, an increase called inflation – just as rapidly as prices are now rising, ours once grew. Universe. This process smoothed out the matter of space-time, which is why that very matter is so evenly distributed in the Universe today.
There is a theory that before the Big Bang, the Universe was an endless strip of ultra-thin dense material that remained stable until, for some reason, the Big Bang occurred. This superdense universe may have been ruled by quantum mechanics, physics on an extremely small scale. Time and space, according to Hawking, are finite, but they have no boundaries, beginnings, or endpoints, just as planet Earth is finite but has no boundaries.
According to another, even more, confusing theory, the Big Bang is not the beginning of time, but rather a moment of symmetry. In this idea, before the explosion, there was a different universe, identical to ours, but with entropy growing towards the past, not towards the future. A kind of mirror image. Proponents of this theory also speculate that other properties would also be reversed in this mirrored universe. Physicist David Sloan of the University of Oxford published a scientific paper in which he argues that asymmetries in molecules and ions (the so-called chiralities) in the mirror universe are opposite to those in our universe.
The Big Bounce suggests that there can be endless Big Bangs as the universe expands, contracts, and expands again. The problem with these ideas is that there is no explanation as to why or how the expanding universe will contract and return to a low entropy state.
In 2004, physicists suggested that perhaps the universe as we know it is a product of the parent universe, from which some space-time has escaped. It’s like the decay of a radioactive nucleus: when the nucleus decays, it spits out an alpha or beta particle. The parent universe can do the same, except that instead of particles, it spits out child universes endlessly.
If all this sounds rather strange, it is because scientists do not yet have the opportunity to look back even at the moment of the Big Bang, and even more so at what came before it. But no matter how far-fetched these or those theories sometimes look, there is nothing without them.
A new study casts doubt on the Big Bang
About 13.8 billion years ago, a certain event gave impetus to the appearance of a hot and dense bunch of elementary particles, including protons and electrons. All this expanded and cooled, the substance became transparent, protons and electrons combined into hydrogen atoms. From hydrogen arose stars, inside of which other elements appeared. As a result, our Universe appeared as we know it. And at the very beginning, there was the Big Bang.
This theory has many supporters, but there are also opponents. One of them is the American popularizer of science Eric Lerner, author of the 1991 book “The Big Bang That Didn’t Happen”. At the next conference of US astronomers, he read a report on the same topic, reports Inverse.
According to this theory, light chemical elements – helium, deuterium, and lithium – began to form during the first minutes of the “explosion”, while heavy ones appeared in the interiors of stars much later.
However, Lerner argues, close observation shows that the number of elements in the universe predicted by the theory does not correspond to reality. For example, according to the theory of nucleosynthesis, about 25% of the mass of the universe should be helium. But the fraction of helium in stars that appeared in the early Universe is less than half, and the fraction of lithium is less than one-tenth of the amount predicted by theory.
Lerner adheres to an alternative theory of the origin of the universe, which he calls the Galactic origin of the light elements. It states that the light elements were created inside stars in the early stages of galaxy formation. This is confirmed by the observation of the oldest stars.