QUARK-GLUON PLASMA

For a few millionths of a second after the Big Bang, the universe consisted of a hot soup of elementary particles called quarks and gluons. A few microseconds later, those particles began cooling to form protons and neutrons, the building blocks of matter. Over the past decade physicists around the world have been trying to re-create that soup, known as quark-gluon plasma by slamming together nuclei of atoms with enough energy to produce trillion degree temperatures. If your interested in the properties of the microseconds-old universe, the best way to study it is not by building a telescope, it's by building an accelerator. Quarks and gluons though they make up protons and neutrons, behave very differently from those heavier particles. Their interactions are governed by a theory known as quantum chromodynamics. However, the actual behavior of quarks and gluons is difficult to study because they are confined within heavier particles. The only place in the universe where quark gluon plasma exists is inside high-speed accelerators, for the briefest flashes of time. In 2005 scientists reported creating quark-gluon plasma by smashing gold atoms together at nearly the speed of light. These collisions can produce temperatures up to four trillion degrees- two hundred fifty times hotter than the Sun's interior and hot enough to melt protons and neutrons into quarks and gluons. The resulting super-hot, super-dense blob of matter, about a trillionth of a centimeter across, could give scientists new insights into the properties of the very early universe. So far, they have already made the surprising discovery that quark-gluon plasma is a nearly frictionless liquid, not the gas physicists had expected. By doing higher-energy collisions, scientists now hope to find out more about the properties of quark-gluon plasma and whether it becomes gas-like at higher temperatures. At the Large Hadron Collider physicists are planning to double the temperature previously achieved, offering a glimpse of an even earlier stage of the universe's formation.