# Simulating the big bang with a 2D superfluid

**URL:** <https://boards.straightdope.com/t/simulating-the-big-bang-with-a-2d-superfluid/668349>\
**Category:** Miscellaneous and Personal Stuff I Must Share\
**Created:** [September 8, 2013, 7:52pm UTC](https://boards.straightdope.com/t/simulating-the-big-bang-with-a-2d-superfluid/668349 "2013-09-08T19:52:24Z")\
**Posts on this page:** 1\
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**Author:** ![deltasigma](https://avatars.discourse-cdn.com/v4/letter/d/e5b9ba/32.png) [@deltasigma](https://boards.straightdope.com/u/deltasigma)\
**Post date:** [September 8, 2013, 7:52pm UTC](https://boards.straightdope.com/t/simulating-the-big-bang-with-a-2d-superfluid/668349/1 "2013-09-08T19:52:24Z")

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I’ll someone else try to give a fuller explanation but the [article](http://news.uchicago.edu/article/2013/08/28/ultracold-big-bang-experiment-successfully-simulates-evolution-early-universe) seems to do a pretty good job.

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> Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the Big Bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago.  
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> It turns out that under certain conditions, a cloud of atoms chilled to a billionth of a degree above absolute zero (-459.67 degrees Fahrenheit) in a vacuum chamber displays phenomena similar to those that unfolded following the Big Bang, Hung said.
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> “At this ultracold temperature, atoms get excited collectively. They act as if they are sound waves in air,” he said. The dense package of matter and radiation that existed in the very early universe generated similar sound-wave excitations, as revealed by COBE, WMAP and the other experiments.  
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> The sudden expansion of the universe during its inflationary period created ripples in space-time in the echo of the Big Bang. One can think of the Big Bang, in oversimplified terms, as an explosion that generated sound, Chin said. The sound waves began interfering with each other, creating complicated patterns. “That’s the origin of complexity we see in the universe,” he said.
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> These excitations are called Sakharov acoustic oscillations, named for Russian physicist Andrei Sakharov, who described the phenomenon in the 1960s. To produce Sakharov oscillations, Chin’s team chilled a flat, smooth cloud of 10,000 or so cesium atoms to a billionth of a degree above absolute zero, creating an exotic state of matter known as a two-dimensional atomic superfluid.  
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> In the end, what matters is not the absolute size of the simulated or the real universes, but their size ratios to the characteristic length scales governing the physics of Sakharov oscillations. “Here, of course, we are pushing this analogy to the extreme,” Chin said.  
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> Today’s CMB maps show a snapshot of how the universe appeared at a moment in time long ago. “From CMB, we don’t really see what happened before that moment, nor do we see what happened after that,” Chin said. But, Hung noted, “In our simulation we can actually monitor the entire evolution of the Sakharov oscillations.”
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> Chin and Hung are interested in continuing this experimental direction with ultracold atoms, branching into a variety of other types of physics, including the simulation of galaxy formation or even the dynamics of black holes.