Cosmologists have long believed that dark energy, the mysterious force driving the universe’s accelerating expansion, is a constant. However, new data from the Dark Energy Spectroscopic Instrument (DESI) collaboration suggests its pulling power may be weakening over time.
The DESI team created the largest 3D map of the universe ever made and tracked dark energy’s influence for 11 billion years. By overlaying their findings with other data, including light from Type Ia supernovae explosions and the cosmic microwave background radiation, a more complex picture of dark energy has emerged. This suggests that its power may decrease over time.
The nature of dark energy determines the universe’s fate. If it acts as a cosmological constant, the universe may end in a “Big Freeze,” with all matter and energy spread thin. Alternatively, if dark energy varies with time, this could lead to a more extreme scenario like a “Big Crunch,” where the universe snaps back into a singularity.
The DESI results are a significant breakthrough for cosmologists. If confirmed, they will rule out or confirm our current theories about dark energy’s nature and shape the future of the universe.
Source: https://www.skyatnightmagazine.com/news/dark-energy-changing