Scientists recreate conditions of first millisecond after "Big Bang" inside particle collider

Physicists have recreated conditions similar to those that existed during the first fraction of a millisecond after the Big Bang by smashing heavy atomic nuclei together at nearly the speed of light inside the Large Hadron Collider (LHC) located over hundred meters beneath the Swiss city of Geneva.

The experiment produced the extreme state of matter known as quark–gluon plasma for a brief moment, which delivered unexpected results for the scientists, as an article by LiveScience points out.

In the earliest universe, temperatures were so high that quarks and gluons, normally confined inside protons and neutrons, moved freely in a dense, ultra-hot medium often described as a primordial soup. 

What surprised researchers is that this material does not behave like a dilute gas of independent particles, as early theories predicted, but instead acts as a strongly interacting liquid with very low viscosity, closer to a nearly perfect fluid.

In the new experiment conducted inside of the world’s largest, most powerful particle accelerator, scientists were able for the first time to observe how an individual high-energy quark travels through this plasma. By tracking collisions in which a neutral Z boson served as a clean reference signal, researchers isolated the motion of single quarks and detected clear wake-like patterns forming behind them, similar to ripples produced by a boat moving through water. 

The LHC has been built by the European Organization for Nuclear Research (CERN) in an international joint-effort with over 10,000 scientists. The tunnel is located within the organization's territory near the French-Swiss border close to Geneva and built over 100 meters in the underground, holding a circumference of 27 kilometers which stretches like a circle across the territories of both countries.

These wakes demonstrate that the plasma responds collectively, confirming that the early universe’s matter flowed coherently rather than behaving chaotically. 

According to the article, the measurements also allowed physicists to estimate how energy spreads through the plasma and how quickly disturbances dissipate, offering direct insight into its density and internal structure.

Because this exotic state of matter existed only for microseconds after the Big Bang before cooling allowed ordinary particles to form, recreating it in accelerators provides one of the few experimental windows into the universe’s earliest physical conditions. 

The results strengthen the idea that the young cosmos was dominated by an extremely hot, strongly coupled liquid rather than a simple particle gas, helping refine models of how matter transitioned from primordial plasma into the building blocks of atoms and, eventually, galaxies.

By Nazrin Sadigova