Scientists: The universe may begin to shrink soon

New research published in the Proceedings of the National Academy of Sciences indicates that after nearly 13.8 billion years of uninterrupted expansion, the universe will soon stop expanding and then slowly begin to shrink.

In the new paper, three scientists try to model the nature of dark energy – a mysterious force that appears to be expanding the universe faster than ever before – based on previous observations of cosmic expansion. Scientific warningt Science.

In this model, dark energy is not a static force of nature, but an object called matter, which decays over time.

Although the expansion of the universe has accelerated for billions of years, researchers have found that the repulsive power of dark energy can be weakened.

According to their model, the acceleration of the universe could end quickly within the next 65 million years, and then within 100 million years, the universe could stop expanding completely, and instead enter into an era of slow contraction that would now end billions of years ago. Death – or perhaps rebirth – time and place.

Paul Steinhardt, director of research at the Princeton Center for Theoretical Science at Princeton University in New Jersey, told the Web site that all of this would happen “remarkably quickly.”

“65 million years ago, it was time for the asteroid to strike Earth and destroy the dinosaurs,” he says, “galactically, 65 million years is remarkably short.”

Gary Henson, a professor of physics and astronomy at the University of British Columbia, said: “There is nothing controversial or unbelievable about this theory.

However, since this model relies solely on previous observations of expansion – and because the current nature of dark energy in the universe is a great mystery – the predictions made in this paper cannot be tested at present.

For now, he adds, theories can only exist.

Vacuum energy

Since the 1990s, scientists have come to understand that the expansion of the universe is accelerating and that interconnected space is expanding faster now than it was billions of years ago.

Scientists have named the mysterious source of this acceleration Dark Energy, an invisible substance that acts against gravity, which splits the largest objects in the universe together.

Although dark energy makes up 70 percent of the total mass energy in the universe, its properties remain an absolute mystery.

A popular theory put forward by Albert Einstein is that dark energy is a cosmological constant – a constant form of unchanging energy that is bound up in the fabric of space-time.

However, competing theory suggests that dark energy does not have to be constant to match previous cosmic expansion observations.

Alternatively, dark energy can be a center – a dynamic field that changes over time.

About five billion years ago, the center became the dominant object, and the effect of gravity accelerated the expansion of the universe.

Dark energy death

In their study, Steinhardt and his colleagues, Anna Igas of New York University and Princeton Cosmin Andre, predicted how the properties of matter would change over the next several billion years.

To do this, the team developed the center’s physics model, which shows its repulsive and attractive force compatible with previous observations of the expansion of the universe.

Once the group model was able to reliably recreate the history of the expansion of the universe, they expanded their predictions for the future.

The model showed that dark energy decays over time. “

According to the team model, the driving force of dark energy may be in the midst of a rapid decline that began billions of years ago.

In other words, after nearly 14 billion years of growth, space will begin to shrink.

First, the contraction of the universe would be so slow that any hypothetical man still alive on Earth would notice a change, Steinhardt said.

But from there, Steinhardt said, one of two things could happen. Its original conditions and another Big Bang or Big “bounce”, create a new universe from the ashes of the old universe.

If this is true, our present universe may not be the first or only universe, but rather the latest in an endless chain of universes expanding and contracting before us, Steinhardt said. And it all depends on the dynamics of the dark energy.