A team of astronomers has questioned the widely accepted theory that the universe is accelerating, suggesting instead that it might be slowing down. The researchers found evidence that dark energy, a mysterious force driving expansion, may be weakening over time.
The study, led by Prof Young-Wook Lee from Yonsei University in South Korea, analyzed data on distant supernovae and estimated the ages of 300 host galaxies. They discovered that variations in star properties might lead to fainter supernovae, which would correct for a previous assumption about galaxy aging.
Although this correction still shows an expanding universe, it implies that expansion has slowed down and dark energy is waning. If dark energy continues to decrease, the universe could theoretically collapse into a “big crunch” scenario. The findings have sparked debate in the scientific community, with some experts viewing them as provocative and worthy of attention.
Source: https://www.theguardian.com/science/2025/nov/06/universe-expansion-slowing-not-accelerating-nobel-prize