Experiments with cold atoms suggest particles fly out of empty space
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A small, expanding cosmic analogue was created from a very cold potassium atom. This could help us understand cosmic phenomena that are very difficult to detect directly, such as particle pairs that can be created from empty space as the universe expands.
Markus Oberthaler Heidelberg University in Germany and his colleagues cooled more than 20,000 potassium atoms in a vacuum, slowed them down using lasers, and lowered their temperature to about 60 nanokelvins (one degree Kelvin below absolute zero). 1).
At this temperature, the atoms formed a hair-wide cloud, and instead of freezing into a quantum fluid-like phase of matter called Bose-Einstein condensation. You can control it. Using small projectors, researchers precisely set the density of atoms, their placement in space, and the forces they exert on each other.
By altering these properties, the team made the atoms obey equations called spatiotemporal metrics. This equation determines how curved the universe is, how fast light travels, and how much light has to bend near very large masses in a real, full-scale universe. . object. This is the first experiment to use cold atoms to simulate a bending and expanding universe, Oberthaler says.
When researchers used projectors to make atoms mimic the expanding universe, the atoms moved exactly in the ripple pattern you’d expect if pairs of particles came into existence. This is a phenomenon called particle pair generation. The researchers say this suggests that pairs of particles could be created in expanding universes like ours.
Alessio Seri Researchers from the Autonomous University of Barcelona in Spain say the new experiment is a highly precise playground that combines quantum effects and gravity. Physicists aren’t quite sure how the two combine in the universe we live in, but experiments with cryogenic atoms may test some ideas. not. It could also inspire new targets for observations in a much larger and more complex universe, he says.
Stephen Flechinger A doctor from the University of Jena in Germany, who was part of the research team, says future experiments on the same system could lead to a better understanding of the quantum properties of our universe.
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