Scientists recreated the first matter that appeared after the Big Bang, by smashing lead particles together at 99.9999991% of the speed of light.
Out of the wreck came a primitive type of matter known as quark-gluon plasma (QGP). It only lasted for a fraction of a second, but for the first time, scientists were able to examine the liquid-like properties of plasma – and find that it has less resistance to flow than any other known substance – and determine how it evolved in the early moments of the early universe.
“This study shows us the evolution of the QGP and eventually [could] suggest how the early universe evolved in the first microsecond after the Big Bang,” said co-author You Zhou, associate professor at the Niels Bohr Institute at the University of Copenhagen in Denmark.
After the Big Bang, the universe was thought to be a soup of energy before it expanded rapidly during a period known as inflation, allowing the universe to cool enough to form matter.
The first entities thought to emerge were quarks, a fundamental particle, and gluons, which carry the strong force that glues quarks together.
As the universe cooled, these particles formed subatomic particles called hadrons, some of which are known as protons and neutrons.
By smashing heavy atomic nuclei together, at the world’s largest atom smasher, the Large Hadron Collider (LHC) on the border of Geneva, Switzerland, scientists could create a tiny fireball that effectively melts particles into their elemental shapes for a fraction of a second.
The scientists think they first created a QGP in 2000, but the latest batch, reported online on May 11, 2021 in the journal Physics Letters B, was the first time they could probe the characteristics of its liquid nature in detail.
Because the plasma lasted only 10 to 23 seconds, the scientists used new computer simulations along with data they collected from an instrument called ALICE – short for the Large Ion Collider Experiment – in the accelerator, to see what properties the matter might have changed between the moment it formed and when it condensed into hadrons.
They found the QGP was a perfect liquid — which means that it had almost no viscosity or resistance to flow — and it also changed shape over time in a manner unlike other forms of matter.
This information helps scientists understand what the universe is like in the first moments after the Big Bang.