Quantum whirlpools can help explain how Big Bang formed universe

October 17th, 2008 - 12:39 pm ICT by IANS  

Sydney, Oct 17 (IANS) Discovering exactly how the Big Bang created the universe may now be a step closer - thanks to the combined efforts of physicists. Experimental physicists from the University of Arizona worked with theoretical physicists from the University of Queensland Ashton Bradley and Matthew Davis to determine how Bose-Einstein condensates (BECs) form.

A Bose-Einstein condensate is a state of matter formed at ultra-cold temperatures, where atoms behave like waves. It was first predicted by Einstein in 1924; S.N. Bose was a young Indian physicist who used the theory to explain certain behaviours of light.

Its practical implications are still not fully appreciated, but the development of “atom lasers” may advance the production of nanotechnology and it may also have applications for super-powerful “quantum computers”.

Bradley said scientists have been able to make vortices - alignments of atoms forming rotating whirlpools within the otherwise stationary atoms of the BEC - by stirring them, said an Otago University press release.

But, until now, they had only suspected that vortices may form spontaneously under the right conditions. For years, physicists have speculated about the possibility of vortices being created as a BEC is born.

“Many people still thought that vortices would not be formed spontaneously, because vortices are quite energetic compared to the ground state of the system.”

The Arizona-Queensland collaboration has been able to show that vortices spontaneously appear between 25 to 50 percent of the time.

“We know that the vortices are a consequence of critical fluctuations occurring as the gas cools, becoming a superfluid Bose-Einstein condensate.”

Bradley said that, by quantifying the occurrence of vortex formation in BECs, physicists understand a little more about the behaviour of the atoms in other phase transitions, such as the emergence of structure in the universe after the Big Bang.

These findings appeared in Nature.

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