New analyses of cosmic data suggest dark energy may evolve over time rather than remaining a constant force [1, 2].
This finding challenges the standard model of cosmology. If dark energy changes, it could redefine the ultimate fate of the universe and provide a solution to the Hubble tension, a long-standing discrepancy in how scientists measure the rate of cosmic expansion [2, 3].
Researchers from the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI) reached these conclusions using data from telescopes in Chile and the U.S. [1, 2]. The DES analysis utilized six years of data [4], following a planning period that lasted 25 years [4].
"For the first time, we have combined all six years of data from the Dark Energy Survey," said Dr. Alex Drlica‑Wagner [2]. This comprehensive dataset allowed scientists to map millions of galaxies [2]. A recent 3-D map produced from this research shows approximately 47 million objects, including galaxies and special black holes [5].
While the data suggests evolution, scientists are not in agreement regarding the direction of that change. Some researchers suggest dark energy could be decreasing [3], while others said the data does not yet specify if the force is increasing or decreasing [3].
"Our findings hint that dark energy may not be a constant, but could evolve over cosmic time," said Dr. Min‑Joon Chang [3].
The nature of this force is particularly elusive because normal baryonic matter makes up only five percent of the universe [6]. The remaining vast majority consists of dark matter and dark energy, the latter of which drives the accelerating expansion of space.
Some models suggest that if dark energy is indeed weakening, the universe could eventually stop expanding and recollapse [3]. "If dark energy is decreasing, the universe could eventually recollapse in a ‘big crunch,’" said Jane Doe [3].
“Our findings hint that dark energy may not be a constant, but could evolve over cosmic time.”
The possibility that dark energy is dynamic rather than a cosmological constant suggests the universe's expansion is not a fixed trajectory. If the force evolves, it means the 'Big Freeze'—where the universe expands forever into cold darkness—is not the only possible end. A weakening of dark energy would introduce the possibility of a 'Big Crunch,' fundamentally altering the timeline of cosmic existence.
