The Universe would begin a contraction stage sooner than expected that would culminate in the end of time and space: from there, it could collapse on itself, generate a new Big Bang or “rebirth & rdquor; from his own ashes. The contraction process would be caused by the weakening of dark energy, which exerts a force contrary to gravity and allows the cosmos to expand.
After almost 13.8 billion years of uninterrupted expansion, the Universe could stop and then start to contract slowlyaccording to new research recently published in the journal Proceedings of the National Academy of Sciences (PNAS).
Scientists believe that this phenomenon would be caused by a decrease in the impact of dark energy, which until now has led to the expansion of the cosmos by working as a “repellent & rdquor; of gravitational forces.
The slow twitch era
According to an article published in Science Alert, the acceleration of the Universe could end rapidly within the next 65 million years: then, within 100 million years, the cosmos would stop expanding altogether and instead enter an era of slow contraction that would end billions of years later, with the “death” of time and space as we know.
In principle, we must take into account that the time scales at the cosmological level are notoriously different from those that govern our daily lives: in the history of the Universe, 65 million years is almost a “sigh”. Within these broad time bands, the dark energy it is the one that would have allowed the Universe to expand, exerting a force opposed to gravity: while gravity tends to bring the planets and stars together and the Universe is compressed, dark energy produces the opposite effect and the cosmos expands .
The big problem is that we know almost nothing about dark energy, only that it is a mysterious force that dominates about 70 percent of the Universe. For Albert Einstein, dark energy is a cosmological constant. What does this mean? That it is an immutable form of energy, interwoven in space-time. If the force exerted by dark energy can never change, then the Universe should continue to expand and speed up forever.
The quintessence that explains the Universe
However, a 1998 study suggests that dark energy need not be constant: it could actually be something called “quintessence”, a dynamic field that changes over time. Starting from this idea, the scientists who developed the new research created a physical model of the quintessence, showing its repellent and attractive power over time.
After reliably reproducing the expansion history of the Universe under this model, they tried to predict its future: based on this parameter, they discovered that dark energy can decay over time. If his strength weakens, the antigravitational property of dark energy disappears and the cosmos slows down and stops its expansion.
What happens after the deceleration and slow contraction processes? According to a study published in 2019, the Universe could follow a cyclical pattern of expansion and contraction, constantly collapsing and resurfacing. At the same time, other explanations indicate that it could contract to recreate the conditions of the Big Bang, generating a new creative burst. In this way, our Universe would be just one more within an endless chain of other cosmoses, which previously existed or will do so in the future.
Reference
Rapidly descending dark energy and the end of cosmic expansion. Cosmin Andrei, Anna Ijjas, and Paul J. Steinhardt. PNAS (2022). DOI:https://doi.org/10.1073/pnas.2200539119