Wednesday, April 20, 2005

Liquid Early Universe

RHIC is another accelerator facility here at the Brookhaven Lab. They try to mimic the conditions of the first microsecond after the Bing Bang by forcing gold ions to collide together. In fact, they just managed to produce the temperature (150,000 bigger than the temperature at the center of the sun) and density that existed at that moment of Bing Bang creation. And while the theoretical models predicted that the elements there should behave like a gas (random rapid motions at several directions) they say something astonishingly different: that they behaved like a well defined, low viscosity fluid!

Fluid motion means that when you apply an excitation then the molecules tend to move in groups, affecting eachother and not at totally random directions. There is a collective effect from the interaction between them, which allows us to describe it with macroscopic fluid equations. This will yield tremendous data regarding what happened at the early stages of the universe - this is a time where no atoms are yet formed, it's just a soup of quarks and gluons.