In some 65 million years, that acceleration could stop completely. In 100 million years, dark energy could take on attractive properties, causing the universe to begin to shrink.
After almost 13.8 billion years of continuous expansion of the universe, that process could be stopped, after which it would start to shrink, new research shows. Based on previous observations of cosmic expansion, scientists have made a model of the nature of dark energy, a mysterious force that makes the universe expand faster. The model showed that dark energy is not a constant force of nature, but a kind of quintessence – an element that may change over time.
They found that the repulsive force of dark energy may be weakening, even though the expansion of the universe has been accelerating for billions of years. According to that model, the universe should stop expanding rapidly in the next 65 million years.
After that, by about 100 million, it would completely stop expanding and begin to slowly shrink, and in many billions of years, there would be death (or rebirth) of time and space. “It simply came to our notice then.If we go back so many years, the Earth was hit by an asteroid that killed most dinosaurs, “said physicist Paul Steinhard of Princeton University in New Jersey.
Scientists have known since the 1990s that the expansion of the universe is accelerating, that is, that the space between galaxies is now expanding faster than a billion years ago. They called the mysterious source of this acceleration dark energy – an invisible bitch that acts against gravity and pushes the most massive objects in space away from each other.
“Nothing in this assumption is controversial or unbelievable,” Gary Hinshaw, a physicist and astronomer at the University of British Columbia, told Live Science. However, since the model is based only on previous observations of space expansion and because the nature of dark energy is a great mystery, it is currently impossible to test the research results.
The energy of emptiness
Scientists have known since the 1990s that the expansion of the universe is accelerating, that is, that the space between galaxies is now expanding faster than a billion years ago. They called the mysterious source of this acceleration dark energy – an invisible entity that acts against gravity and pushes the most massive objects in space away from each other.
Although dark energy makes up approximately 70 percent of the total mass-energy of the universe, its properties are still mysterious. According to a popular theory introduced by Albert Einstein, dark energy is a cosmological constant – an unchanging form of energy woven into the fabric of space-time. If this is the case, dark energy never changes and the accelerated expansion of the universe should continue indefinitely.
Competitive theory, on the other hand, suggests that dark energy does not have to be constant in order for its properties to coincide with previous observations of cosmic expansion. Instead, it can be a quintessence, a dynamic field that changes over time. Unlike the cosmological constant, quintessence can be either repulsive or attractive, depending on the extent of its kinetic and potential energy. Over the past 14 billion years, quintessence has had repulsive properties.
Death of dark energy
Steinhard and colleagues predicted in the study that the properties of quintessence could change over the next few billion years. They created a model of quintessence that shows its repulsive and attractive force over time. To their surprise, the model showed that dark energy can begin to weaken over time. Eventually, the antigravity property of dark energy could disappear completely and it could return to something resembling ordinary matter.
According to this scenario, the rapid expansion of space has already begun to slow down. In some 65 million years, that acceleration could stop completely. In 100 million years, dark energy could take on attractive properties, causing the universe to begin to shrink. The end of space?
Paul Steinhard speculates that two things could happen in the end: Either the universe will shrink until it collapses on its own, killing space-time as we know it, or it will shrink to a state similar to the original conditions where it would there could be the creation of a new big bang. “In the case of the second scenario, this would mean that the universe follows a cyclical pattern of expansion and contraction and that our current universe may not be the first or only; only the latest in an endless series of universes “, Steinhard pointed out. “Unfortunately, there is no good way to check whether the quintessence is real and whether the rapid expansion of space has begun to slow down.”