Of the many alternative ways the universe might end, nothing is as scary as “false vacuum decay”. This scenario is based on the idea that a fundamental field in the universe is not at its lowest possible state. Under that “false” stable region, our own universe has grown. The field might spontaneously jump into a more stable value, creating a bubble that wipes out all reality.
We don’t know enough about the field in question – the Higgs field that gives mass to everything – to know how likely this is as a possibility. is when a not-stable state turns into a true stable state, though In general, there’s a lot we don’t understand about how this bubble formation works, especially experimentally. Now, a group of Italian experimentalists and British theoreticians have produced the first experimental evidence of vacuum decay.
“Vacuum decay is thought to play a central role in the creation of space, time, and matter in the Big Bang, but until now there has been no experimental test,” Ian Moss, Professor of Theoretical Cosmology at Newcastle University. “In particle physics, vacuum decay of the Higgs boson would alter the laws of physics, producing what has been described as the ‘ultimate ecological catastrophe’.”
For the first time, scientists have observed the bubbles forming in a controlled atmoic system. The analogous setup they used for the false vacuum scenario was a supercooled vapor at a temperature less than a millionth of a degree from absolute zero. This is a metastable state, which means that it’s not the most stable configuration but it could stay like that for an indefinite amount of time. You can picture it as a little valley on the side of a hill. The lower energy state is at the bottom but this little dent could work for a while.
In quantum mechanics, things don’t even have to have the extra energy to get out of the little valley. They can simply tunnel and decay to the lowest energy state. In the analogous setup, thermal effects work similarly, leading to the formation of a bubble. The bubble expands leading the system into its lowest energy state, akin to the true vacuum.
“Using the power of ultracold atom experiments to simulate analogs of quantum physics in other systems—in this case, the early universe itself—is a very exciting area of research at the moment,” co-author Dr Tom Billam, also at Newcastle, added.
The team’s goal is to push the temperature of the system closer and closer to absolute zero. Under those conditions, the thermal effects will become less relevant but the quantum effects should appear, delivering a more accurate analogous to the false vacuum decay.
The study is published in .