A MICROSECOND after the big bang, when the exploding fireball of the newborn universe was only a few kilometres across, all matter existed in a special state. The basic building blocks of matter – quarks and electrons – floated freely in an incredibly hot, dense soup. As the universe grew and cooled, the quarks bound together into the protons and neutrons that abound today.
This is what physicists think happened at the beginning of the universe. To prove it, teams at particle accelerators all over the world have been racing to recreate that primordial soup – called quark-gluon plasma. Physicists at CERN,…
