Experimenters have reproduced an analogue of the Big Bang in the laboratory. To do this, they used an exotic quantum state of matter known as the Bose-Einstein condensate (BEC). The achievement is described in a scientific paper published in the journal Physical Review X by a group led by Gretchen Campbell of the University of Maryland in the United States.
"Vesti. Nauka" (nauka.vesti.ru) spoke in detail about the nature of KBE. This state can be obtained by cooling the substance to temperatures that differ by negligible fractions of a degree from absolute zero (-273 ° C). It is commonly used to study quantum physics. However, sometimes scientists use EBE as a model for global astrophysical processes.
This time they were interested in the earliest stage in the life of the universe, known as the era of inflation. It is believed that then in 10-35 seconds the volume of space increased at least 1030 times. The beginning of this process is considered the Big Bang in modern cosmology.
"Our knowledge of this expansion is limited to what we can figure out by observing [modern space], since it is understandably a little difficult to create a universe in a laboratory," Campbell quoted Space.com as saying. "One of the potential laboratory models of the Universe is the expanding BEC, an exotic state of ultracold matter where the wave functions of atoms overlap and atoms behave as one."
Physicists have cooled several hundred thousand sodium-23 atoms to an ultra-low temperature, due to which they went into the state of BEC. Then, in several series of experiments, this cloud expanded at supersonic speed. For example, in just a millisecond, its volume quadrupled. This, of course, is far from the rate of cosmological inflation, but scientists have reason to believe that these processes are similar.
According to cosmologists, as the expansion of the Universe slowed down, particles were born from the energy of the field that generated inflation. Similarly to this process, as the expansion of the KBE cloud slowed down, various structures were born in it, including vortices and special single waves, the so-called solitons. During the interaction of newborn particles in the young Universe, the energy stored in them was released, which led to the heating of the substance (the temperature rose to enormous values). Approximately the same was observed in the interaction of structures in the BEC.
“I was actually surprised at how well our theoretical calculations matched what we saw in the lab and how well it worked out,” Campbell admits.
In the future, the authors plan to study in more detail the complex interactions in the KBE cloud in search of new effects, the cosmological analogs of which may later be found in astronomical observations.
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“The best part is that thanks to these results, we now know how to design future experiments to get the different effects that we hope to see,” Campbell says.