Live Science reports:

After nearly 13.8 billion years of nonstop expansion, the universe could soon grind to a standstill, then slowly start to contract, new research published in the journal Proceedings of the National Academy of Sciences suggests.

In the new paper, three scientists attempt to model the nature of dark energy — a mysterious force that seems to be causing the universe to expand ever faster — based on past observations of cosmic expansion. In the team’s model, dark energy is not a constant force of nature, but an entity called quintessence, which can decay over time.

The researchers found that, even though the expansion of the universe has been accelerating for billions of years, the repellent force of dark energy may be weakening. According to their model, the acceleration of the universe could rapidly end within the next 65 million years — then, within 100 million years, the universe could stop expanding altogether, and instead it could enter an era of slow contraction that ends billions of years from now with the death — or perhaps the rebirth — of time and space.

And this could all happen “remarkably” quickly, said study co-author Paul Steinhardt, Director of the Princeton Center for Theoretical Science at Princeton University in New Jersey. [Continue reading…]