Scientists are homing in on the nature of a mysterious force called dark energy, and nothing short of the fate of the universe hangs in the balance.

Scientists with the Dark Energy Spectroscopic Instrument (DESI), an international research collaboration, presented new evidence Wednesday that bolstered its recent finding that dark energy is not inexorably pushing the universe apart at a constant rate of acceleration but rather ebbs and flows and appears to be weakening.

Using data from nearly 15 million galaxies and quasars, the Dark Energy Spectroscopic Instrument (DESI) has created the most detailed 3D map of the universe ever made. A new analysis combining DESI’s observations with other major cosmic datasets suggests that dark energy,