Researchers at the University of Copenhagen have discovered what happens in a particular form of plasma – the first matter in the universe – during the first millisecond of the Big Bang (one microsecond is equivalent to 0.0001.second or 10− 6 or 1⁄1,000,000 seconds).
Their discovery provides a piece of the puzzle of the evolution of this universe as we know it today.
About 14 billion years ago, our universe went from a hotter, denser state to fully expanding – a process scientists have called the Big Bang.
And while we know that this rapid expansion created particles, atoms, stars, galaxies, and life as we know it today, the details of how it happened are still unclear. .
Now, a new study “Measurements of mixed harmonic cumulants in Pb – Pb collisions at sNN = 5.02 TeV” published in the journal Physics Letters B by researchers at the University of Copenhagen has revealed new information about how they started.
“We studied quark-gluon plasma – a state of matter that only existed during the first microsecond of the Big Bang. Our results tell a unique story of how this plasma evolved in this early universe, ”said You Zhou, associate professor at the Niels Bohr Institute at the University of Copenhagen.
“First, plasma is made up of quarks and gluons that have been separated by the hot expansion of the universe. The pieces of quarks then reformed into particles called hadrons. A hardron with three quarks produces a proton, which belongs to the atomic nucleus. These nuclei are the basic building blocks of the earth, of ours and of the universe around us, ”he added.
From fluid form to the mighty building blocks of life
Quark-gluon plasma (QGP) was present during the first millisecond of the Big Bang, then disappeared due to cosmic expansion. But using CERN’s Large Hadron Collider, researchers were able to piece together the first material in the history of the universe and trace what happened to it.
“This accelerator collides ions in the plasma at extremely high speeds, almost identical to the speed of light. This allows us to see how QGP evolves from its own matter into the nucleus of atoms and the building blocks of life, ”You Zhou said.
“In addition to using the Large Hadron Collider, the researchers also developed an algorithm that can analyze the overall expansion of more particles produced at a time than before. These results demonstrate that QGP is useful as a soft liquid form which can be distinguished from other materials by continuously changing shape over time.
“For a long time, researchers thought this plasma was a form of gas, but our analysis confirms an important new measurement, where the Hadron Collider shows that QGP has a soft, fluid texture like water. The new details we are providing show that this form of plasma has changed shape over time, which is completely different from anything we know of and what we can expect, “You Zhou said.
One step closer to the truth about the Big Bang
Even thinking it might be a small detail, it brings physicists one step closer to solving the Big Bang problem and how the universe evolved in the first millisecond, he said.
“Each discovery is a brick that can give us the opportunity to uncover the truth about the Big Bang. It took us 20 years to discover the very fluid quark-gluon plasma before it turned into hadrons and the building blocks of life. Therefore, the new understanding of plasma behavior is a breakthrough for us, ”concludes You Zhou.
