Experts are testing all kinds of interesting data about our universe, so let’s check out what are the latest reports about what they found.
The Universe in a lab
Researchers at the Kirchhoff-Institut für Physik in Germany have been working on simulating the early Universe shortly after the Big Bang. They have created a fascinating tabletop quantum field simulation that uses magnets and lasers to control a sample of potassium-39 atoms, which is kept close to absolute zero.
By using equations to translate the results at this small scale, they aim to explore possible features of the early Universe.
Their work has shown that it is possible to simulate a Universe with a different curvature. In a positively curved universe, if you travel in any direction in a straight line, you will end up where you started. In a negatively curved universe, space is bent in a saddle shape. According to Marius Sparn, a PhD student at Kirchhoff-Institut für Physik, the Universe is currently flat or nearly flat. However, at the beginning of its existence, it might have been more positively or negatively curved.
“If you have a sphere that’s really huge, like the Earth or something, if you see only a small part of it, you don’t know—is it closed or is it infinitely open?” said Sabine Hossenfelder, member of the Munich Center for Mathematical Philosophy.
“It becomes a philosophical question, really. The only things we know come from the part of the Universe we observe. Normally, the way that people phrase it is that, for all we know, the curvature in this part of the Universe is compatible with zero.”
Sparn was one of the authors of a research paper, “Quantum Field Simulator for Dynamics in Curved Spacetime,” which was published in Nature in November 2022.
The team of scientists, comprising members from Belgium, Spain, and Germany, collaborated to study three possible scenarios for the early expansion of the Universe – constant, accelerated, and decelerated.
To make inferences about the behavior of the early Universe, the team combined equations for the Universe and equations for the Bose-Einstein condensate.
Sparn, a member of the team, explained that they simulated positive curvature by increasing the density of potassium-39 from the center of the experimental setup outward and simulated negative curvature by decreasing it.
“We showed that it is possible to simulate spatially curved and expanding spacetimes in a Bose-Einstein condensate,” Sparn said. “This is what you need for a homogeneous and isotropic universe, which should be a fair assumption on large scales.”
