Physicists calculate when the universe will end
Over the next 11 billion years, the universe will continue to expand, before stopping and reversing course, collapsing into a hypothetical Big Bang
If recent discoveries about the movement of dark energy are confirmed by science, our universe will collapse under its own gravity within a finite time frame, new calculations suggest. Scientists have tentatively determined that time frame.
Based on the results of a number of recent studies on dark energy, the new model finds that the universe has a lifespan of just 33.3 billion years. Since we are now 13.8 billion years after the Big Bang, this suggests that we have just under 20 billion years left.
Over the next 11 billion years, the Universe will continue to expand, before stopping and reversing course, collapsing into a hypothetical Big Bang, according to physicists Hoang Nan Lu of the Donostia International Physics Center in Spain, Yu-Cheng Qiu of Shanghai Jiao Tong University in China, and corresponding author Henry Tai of Cornell University in the United States.
“For the past 20 years, people believed that the cosmological constant was positive and that the universe would expand forever,” says Ty, adding: “New data seems to indicate that the cosmological constant is negative and that the universe will end with a Big Bang.”
The cosmological constant Ty is referring to is λ, introduced by Albert Einstein in his general theory of relativity to describe the expansion of the universe. If the value of λ is positive, then it acts as a force that is constantly going outward, contributing to the expansion of the universe. If λ is negative, it behaves like a constant gravity that never goes away and can eventually stop and reverse the expansion.
Recent observations suggest that dark energy can change over time. In the new model for the analyses, everything points to a small negative value of λ, although the current data do not exclude that λ is equal to 0. Since negative λ pulls inward, this would hinder, not help, the expansion of the universe.
“However, the universe is indeed expanding, according to the overwhelming majority of evidence. But based on observations and analyses, we can arrive at a possible behavior of the universe if we combine a small negative λ with an ultralight axion field that today behaves like dark energy.”
“Axions are ultralight particles that can also be considered a type of field that extends through space and were first proposed as such a few decades ago as a potential solution to some other problems in particle physics,” the scientists explain.
In their new analysis, Ty and his colleagues describe the axion as a force that gives the universe a small outward push, but which slowly diminishes over time.
At this point, the axion’s influence still dominates, pushing the universe outward at a high acceleration, as gravity weakens between bodies moving farther and farther apart—so the universe is still accelerating under this scenario, Dnevnik reports.