In the moments following the Big Bang, the extreme heat and pressure coerced matter into a goopy mix of tiny particles. But how goopy? The answer had remained rather unclear to physicists\u2014until now.<\/p>\n
Quarks and gluons are fundamental particles that make up protons and neutrons. These particles are typically bound together, but the extreme conditions after the Big Bang, physicists believe, led to their separate existence in a soupy form called the quark-gluon plasma (QGP). In a recent Physics Letters B<\/a> paper, physicists at CERN\u2019s CMS Collaboration<\/a> and MIT have observed and confirmed for the first time that QGP does indeed behave like a liquid. The quarks in the plasma create waves as they speed through the material, \u201csimilar to a duck trailing ripples through water,\u201d the researchers explained to MIT News<\/a>.<\/p>\n \u201cNow we see the plasma is incredibly dense, such that it is able to slow down a quark, and produces splashes and swirls like a liquid,\u201d explained Yen-Jie Lee, an MIT physicist who led the new research. \u201cSo quark-gluon plasma really is a primordial soup.\u201d<\/p>\n The universe\u2019s goopy days <\/p>\n There isn\u2019t much that scientists know for certain about the super early universe. Physicists have proposed a number of theories and models<\/a> to capture aspects of our universe\u2019s early days. However, the challenge of confirming these ideas through experiments meant scientists were hesitant to draw any firm conclusions.<\/p>\n Related article<\/strong>: New York\u2019s \u2018Big Bang Machine\u2019 Passes Critical First Test<\/a><\/p>\n That said, the QGP had been one of the few concepts scientists generally agreed on. The primordial stew\u2014boiling at around a few trillion degrees\u2014eventually cooled down to create protons and neutrons that make up matter in the universe. One model<\/a>, devised by MIT physicist Krishna Rajagopal, argued that a particle flying through the QGP should produce a wake in the plasma, which would ripple and splash like a liquid.<\/p>\n \u201cThis is something that many of us have argued must be there for a good many years, and that many experiments have looked for,\u201d said Rajagopal, who wasn\u2019t directly involved in the new work.<\/p>\n Studying the cosmic soup <\/p>\n