After all we know and can observe, space is expanding.If one extrapolates the expansion within the framework of the General Theory of Relativity further and further into the past – as if one were playing the cosmic film backwards – one gets to an unpleasant point in the equations: singularity.
Here physics collapses, the laws of nature lose their validity and scientific statements are impossible, because temperature and density become infinite, while space and time become zero.For decades, many cosmologists did not believe that expansion really hinted at such a strange state.
Einstein, too, had initially questioned the Big Bang theory, but came to the same conclusions in the last years of his life.Only what the Big Bang was/is, no one knows!
The Big Bang singularity does not explain anything, but only means theend of all explanations.And first of all, it is only a mathematical limit and does not necessarily have to have an equivalent in reality. Bold scientific and philosophical speculations about how the Big Bang or the emergence of matter and energy occurred are therefore not pointless from the outset – albeit at present, difficult and only indirectly verifiable through observations. After all, the development of recent years shows that it is possible to formulate answers to the question of how the Big Bang came about with scientific hypotheses. Singularity is therefore no longer an absolute, insurmountable stop sign for our knowledge.
Some models assume an empty – that is, matter-free – space-time.If it is dominated by a vacuum energy, it may have contracted from infinity and eternity and created matter as it passed through a minimum size. The Pre Big Bang model has existed for ages before the Big Bang in an infinite, matter-free, cold space.
According to string theory, it is necessarily filled with a so-called dilaton field, which locally leads to a kind of inflation.”Starting from an almost trivial state, the universe would have evolved into an ever-increasing curvature,” says Gabriele Veneziano of the European Nuclear Research Centre CERN, who co-founded string theory and, together with Maurizio Gasperini of the University of Bari, Italy, which has developed a pre-big-bang scenario. Veneziano speaks of an “asymptotic historical triviality” – the initial conditions could hardly be simpler.
But for all of us, we have to bear in mind that there can be no time without space and no space without space.Both require each other:
Hawking himself tried to undermine the inevitability of the Big Bang singularity.For the General Theory of Relativity cannot be valid for the very first fractions of a second if the density and energy exceed certain values. Then quantum effects play a role, which necessitate a quantum theory of gravity. Hawking, along with James Hartle of the University of California, Santa Barbara, found a mathematical trick to boot out singularity.
For this purpose, they introduced an imaginary time: by multiplying by factor i – the root of minus one – time became, as it were, a fourth spatial coordinate, which in the coordinate cross is permanletating to the ordinary time.”Let’s say that the imaginary time corresponds to the latitudes. Then begin the history of the universe in imaginary time at the South Pole. There would be no point in asking, ‘What happened before the beginning?’ Such imaginary times are simply not defined, as few as there are points south of the South Pole,” Hawking writes.
In the Hawking-Hartle model, the pointed singularity is replaced by a rounded cap – the instanton – where the coordinates meet like at the South Pole.”If the universe is really completely self-contained, if it really has no boundary and no edge, then it would have neither a beginning nor an end,” Hawking is convinced. “It would be easy.” The original model assumes a high density of matter and the assumption that the expansion of the universe will eventually reverse. Both can no longer be reconciled with the current observation ales. But together with Neil Turok of the University of Cambridge, Hawking succeeded in translating the basic idea of the imaginary period to open, i.e. eternally expanding universes (image of science 5/1998, “Stephen Hawking’s world model”). Turok, due to its similar size, compares the Instanton somewhat disrespectfully to a pea and speaks of a “one shot” universe with “a beginning and a big bang”.
This scenario is thus drastically different from the model of eternal inflation, in which “our” Big Bang was just one of many.Of course, the Hawking-Turok model also causes considerable difficulties: it predicts far too low material density, it cannot yet explain how the real one emerges from the imaginary time, and even the singularity is not completely banished, but harmless and as it were sidelined. Turok: “We have kind of evaded singularity without being able to avoid it altogether. We found a way to the origin and were able to bypass the singularity.”
Nevertheless, not all scientists are convinced: the hypothesis of the quantum vacuum as the simplest possible physical state without space and time.A quantum tunnel effect could have made our universe (and many others) “literally out of nowhere,” says Alexander Vilenkin of Tufts University in Medford, Massachusetts. In this quantum tunnel effect model, nothingness is in a sense unstable and therefore randomly produces universes. Many of them are deserted, empty and short-lived, but some can grow large by an inflation ary. “Let’s forget the initial conditions,” Suggests Vilenkin, and his calculations make universes bubble from the quantum foam like bubbles of boiling water.
The Big Bang would then only be the beginning of our space-time, not of the cosmos as a whole.Whether this is eternal, as the model of chaotic inflation that Andrei Linde of Stanford University has developed, or even began with a first universe and big bang, as Alexander Vilenkin argues, is debatable. Others even dare to hypothesis a time loop. After that, the universe created itself by resorting to its own past. “The universe is, in a way, its own mother,” says Richard Gott III of Princeton University, who developed this self-creation model with Li-Xin Li. “We believe that the universe was not born out of nothing, but descended from something, and that something is itself.” So we have a simultaneity of everything, we can’t see that. There is no counter-fight, no past, no future, nut that is all.
After all, current cosmology proves that overcoming the Big Bang singularity opens up a wealth of new possibilities.No one would argue that research on the edge of the conceivable is a leisurely walk. For Michael Turner, the effort is not a glass bead game. The physicist at the University of Chicago prefers to compare cosmologists to jazz musicians who collect various themes for their compositions and improvisations. “You hear something and say, “Oh yeah, we want to have that in the finished piece.”” The only incomprehensible thing about the universe is its comprehensibility, Albert Einstein once said. “The majesty is in comprehensibility,” says Michael Turner. “The human spirit is able to read from a few relics how it all began.”
Long talk, but it was necessary.Because just as often as is done, everything is not, only more or less likely!
When we calculate how much energy is present in space today, we also know how much was present at the time of the formation, or at least very briefly.Because energy is not lost, it just changes. Energy cannot be generated or destroyed. This conservation set is considered sacrosanct to physicists. He dominates every area of life – the warming of a cup of coffee, the chemical reactions with which leaves produce oxygen, the orbit of the earth around the sun and the food we need for our heart to beat. We cannot live without food, the car does not drive without fuel, and perpetuum mobiles are pure fiction.
In the model I lean towards, the strings first appeared in our universe and then the first quarks, the next more elemant building blocks of subatomic particles such as protons and neutrons.Although antimatter, especially antiprotons and antielectrons, destroyed most of the matter, enough of it remained. As this matter cooled further, the first atomic nuclei formed in it. And because there was something, there was a room and if something happens in a room, there is also a time (whichever)
Between these three minutes and a time 300,000 years later, the reduced energies allowed the electrons to bind to the atomic nuclei in order to form the first hydrogen and helium atoms.From that moment on, however, to the observed most recent galaxies about two to three billion years later, only blank pages can be found in the history book of the cosmos.
At the same time, darker matter and dark energy and antimatter and antienergy appeared.All this in the first three minutes after “whatever- ever” for an initial explosion in space. The ingredients with which the stars were supposed to start had been provided in this short time. At least that is what the “standard model” that is widely accepted today wants.
And that’s the problem now, we can’t calculate what mass/energy our universe has, and since we don’t know that, we don’t know how much it had after the Big Bang.