Thursday, 3 June 2010

The First Few Microseconds

Being able to recreate the beginning of all time, space and matter seems like a work of science fiction. But scientists at Brookhaven National Laboratory have been simulating the first few microseconds of the big bang for over five years using the Relativistic Heavy Ion Collider (RHIC).

During the early stages of the big bang a concoction of quarks, antiquarks (the subatomic particles within nuclei) and gluons are formed which become bound together by strong forces into hadrons (neutrons and protons) within 10 microseconds. The same quark gluon brew is formed in the RHIC, with the vital characteristic of being momentarily unchained by colliding two beams of gold nuclei at 99.99% the speed of light creating a fireball 4 times smaller than an atom, and generating the immense conditions of the big bang (1030 times atmospheric pressure, temperatures exceeding trillions of degrees). Examining the data has come up with surprising results. Originally, the quark-gluon plasma was thought to behave like a gas, but scientists now understand it to have liquid properties. Evidence of this comes from collisions occurring off centre, releasing more hadrons in one direction than uniformly. This indicates that before forming into hadrons, the particles behave collectively as a perfect liquid with no viscosity.

These new discoveries have spun off further investigations to deepen the knowledge of the infant universe. Experiments are planned to study the spectrum and types of quarks emitted from the quark gluon liquid. Next year, RHIC physicists will join the international alliance of particle researchers at the Large Hadron Collider in CERN, where they hope to count down to the first microsecond of the big bang. Whether these new results will match those already found is unsure, but for now, the secrets of the big bang will remain hidden in the past.