Dark energy, the mysterious force that makes up 70 percent of everything in the universe, was hypothesized to explain why the expansion of the universe was accelerating. It has long thought to be a constant, immutable presence. Now, the latest observations from the Dark Energy Spectroscopic Instrument (DESI) indicate that dark energy has changed over time — a development that could potentially upend the prevailing cosmological model, and perhaps hint at a new physics. The findings, detailed in a series of papers awaiting peer-review, have implications for not only how the universe has evolved, but what its eventual fate might […]