In the initial moments of the universe, matter as we recognize it did not exist. Roughly a millionth of a second after the Big Bang, the cosmos was a dense, searing soup known as quark-gluon plasma (QGP). While particle colliders have replicated this state for years by smashing heavy elements like lead, a recent experiment at the European Organization for Nuclear Research (CERN) has demonstrated that this plasma can be produced by much smaller collisions.
Scaling Down the Early Universe
According to a study published in Physical Review Letters, an international team of collaborators generated QGP using oxygen-16 and neon-20. Both elements are less than a tenth of the weight of a lead atom, which was previously established as one of the lightest elements capable of producing the substance. This discovery challenges previous assumptions about the scale required to observe such extreme states of matter.
Quarks are the fundamental components of protons and neutrons, while gluons act as the force that binds them together. During the universe's first microseconds, these were not confined within larger particles but flowed in an extremely hot plasma. As the universe expanded and cooled, these quarks eventually condensed into the building blocks of matter.
Fluid Behavior in Micro-Collisions
The research focused on understanding the limits of this state of matter—specifically, how small a collision can be while still behaving like a drop of fluid. Despite the small size of the oxygen and neon nuclei, the collisions at CERN produced signals consistent with QGP behavior. The matter expanded collectively like a fluid before cooling and reverting to standard particles.
“We have pushed the boundary for how small the atomic nuclei can be while still re-creating this primordial matter—what you could call a ‘little big bang,’” explained You Zhou, a researcher at the Niels Bohr Institute in the Netherlands.
The findings provide new insights into the fundamental conditions required for matter to transition into extreme states and how the primordial sludge evolved into the universe we inhabit today.
