When Will Universe Die? A New Theory Sets It End at 33 Billion Years

A recent theory, inspired by data from major sky surveys, suggests that the universe might cease expanding in about 10 billion years. It could then start collapsing, leading to a final end just 33 billion years from now. While this timeline seems distant, in cosmic terms, it's alarmingly close.

Over the past year, astronomers using the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) have observed something intriguing. The mysterious force known as dark energy, which causes the universe to expand rapidly, might not be constant. If true, this challenges a fundamental assumption of modern physics: that dark energy is stable and unchanging.

Dark Energy's Changing Nature

The current dominant model for dark energy is the cosmological constant, introduced by Einstein over a century ago. However, recent observations suggest this constant may not fully explain what's happening. A new paper from June proposes a more complex idea: dark energy consists of two components.

The first component is an axion—a hypothetical particle so light and elusive it rarely interacts with anything. These axions can be imagined as a gentle energy mist stretching across the universe, driving its accelerated expansion. The second component is the cosmological constant but with a negative value.

The Big Crunch Theory

Unlike a positive constant that pushes space outward, a negative one would pull it back. Currently, axions are responsible for most of the expansion work. However, as time progresses, axions are expected to diminish. When they do, the negative cosmological constant will take over—slowing down expansion and eventually reversing it.

This reversal could initiate a dramatic phase known as the Big Crunch. Galaxies would collide; space would contract; the universe would heat up and become denser until it spirals into a final singularity—the opposite of the Big Bang.

Speculative Yet Intriguing

The theorists predict that this "beginning of the end" will commence in about 10 billion years—less than the universe's current age. Afterward, another 10 billion years would pass before everything collapses completely. This implies that our universe's total lifespan could be around 33 billion years—indicating it's already beyond halfway through its existence.

It's important to note that this theory remains highly speculative at present. The findings from DES and DESI are preliminary results requiring confirmation through future observations. Even if proven inaccurate regarding cosmological constants' nature alone doesn't validate this two-part axion model entirely.

Nevertheless, these insights open doors for new questions about our universe's ultimate fate while we continue observing its expansion—and watching skies unfold mysteries yet untold.