The first millisecond of the universe: How big bang matter drips out of the tap
The beginning of the universe is notoriously difficult to investigate. Anyone who has read my book «The Disruption» (coming soon in English) knows the problem. This is not so much because it happened so long ago. Whereas 13.8 billion years are also a long time. It is more difficult for scientists because they have not yet fully understood the physics of the great beginning. Under the extreme, today hardly in the experiment to be imitated conditions at that time still completely different, superordinate laws applied, which we must still find out slowly. There are already some suggestions. And there are also always new findings – which can sometimes be surprising. Or would you have thought that the matter existing at that time possessed very similar properties as water that comes with you from the tap?
«We studied a substance called quark gluon plasma (QGP), which was the only matter that existed during the first microsecond of the Big Bang. Our results tell us a unique story of how plasma evolved in the early stages of the universe,» explains You Zhou, associate professor at the Niels Bohr Institute at the University of Copenhagen. «First, the plasma, which consisted of quarks and gluons, was separated into its components by the hot expansion of the universe. Then the quark pieces formed into what are called hadrons. A hadron with three quarks forms a proton, which is part of atomic nuclei. These nuclei are the building blocks that make up the Earth, ourselves, and the universe that surrounds us.»
The quark-gluon plasma (QGP) was present in the first 0.000001 seconds of the Big Bang and then disappeared due to expansion. But with the help of the Large Hadron Collider at CERN, researchers have been able to recover this first matter in history and trace what happened to it. «The collider smashes ions from the plasma together at great speed – almost the speed of light. This allows us to see how the QGP evolved from its own matter to the nuclei in atoms and the building blocks of life,» You Zhou says.
«For a long time, researchers thought the QGP was a form of gas, but our analysis confirms the measurement, where the Hadron Collider shows that the QGP was liquid and had a smooth, soft texture like water. This is quite surprising and different from any other matter we know and what we would have expected,» You Zhou says. Although this may seem like a small detail, it brings us one step closer to solving the mystery of the Big Bang and the formation of the universe in the first microsecond, he continues. «Each discovery is a building block that improves our chances of finding out the truth about the Big Bang. It took us about 20 years to figure out that the quark-gluon plasma was liquid before it turned into hadrons and the building blocks of life. So our new knowledge of the ever-changing behavior of plasma is a major breakthrough for us.»