“This is the first time an experiment like this has simulated the evolution of structure in the early universe,”
said Cheng Chin, professor in physics. Chin pursued the project with lead author Chen-Lung Hung, PhD’11, now at the California Institute of Technology
, and Victor Gurarie of theUniversity of Colorado, Boulder
. Their goal was to harness ultracold atoms for simulations of the Big Bang to better understand how structure evolved in the infant universe.
The cosmic microwave background is the echo of the Big Bang. Extensive measurements of the CMB have come from the orbiting Cosmic Background Explorer in the 1990s, and later by theWilkinson Microwave Anisotropy Probe and various ground-based observatories, including theUChicago-led South Pole Telescope collaboration. These tools have provided cosmologists with a snapshot of how the universe appeared approximately 380,000 years following the Big Bang, which marked the beginning of our universe.
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.
“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.