According to a study published in the Journal of Cosmology and Astroparticle Physics, scientists estimate that the total age of the universe will reach 33.3 billion years. Since the current universe is 13.8 billion years old, this means that we have about 19.5 billion years before the end.

The research team, consisting of Huang Nan Liu from the Donostia International Center for Physics in Spain, Yu-Cheng Qiu from Shanghai Jiao Tong University in China, and Henry Tai from Cornell University in the United States, explains that the universe is in three successive stages, as it will continue to expand for the next 11 billion years to reach a size equivalent to 1.7 times its current size. After that, it will reach a critical stopping point, after which a phase of rapid contraction will begin that will continue for 8 billion years, ending with what is known as the “Big Crunch.”

Professor Tai explains these results, saying: “For the past 20 years, we believed that the universe would continue to expand forever, but new data indicate that the cosmological constant may be negative, which will ultimately lead to the end of the universe.”

These expectations are based on the important hypothesis that dark energy changes with the passage of time, and that the cosmological constant (λ) that Einstein established in his theory of relativity may have a negative value. This means that instead of acting as a driving force for expansion, it will act as an attractive force driving the universe towards contraction.

To explain this complex mechanism, scientists combine the hypothesis of the negative cosmological constant with the theory of axions, which are ultra-light particles that behave like dark energy. This process can be likened to a cyclist ascending a slope with the help of a tailwind. The wind pushes him strongly at first, then gradually weakens until he stops at the top, after which he begins a rapid descent.

The research team confirms that these expectations are still within the framework of hypotheses that need more scientific proof. The nature of dark energy remains one of the greatest mysteries in cosmology, and there may be other unknown factors affecting the fate of the universe. However, this study remains an important step towards better understanding the fate of our universe, as Professor Tai concludes by saying: “Knowing the end of the universe is as important as knowing its beginning, as it helps us understand our cosmic destiny more deeply.”

Source: ScienceAlert