New cosmological calculations led by physicists at Cornell University and Shanghai Jiao Tong University suggest the universe’s accelerating expansion is temporary. Drawing on data from the Dark Energy Survey and the Dark Energy Spectroscopic Instrument, the team modelled dark energy as a combination of an ultra-light axion-like particle and a small negative cosmological constant. Their so-called aDE model indicates that expansion will peak in roughly 7 billion years, after which gravity will regain the upper hand, triggering a long contraction that culminates in a “Big Crunch” about 33.3 billion years from the Big Bang. The work challenges the prevailing view that dark energy is constant and will drive eternal expansion. By fitting subtle deviations in supernova brightness, galaxy clustering and gravitational-lensing data, the researchers argue that a dynamic dark-energy component better matches observations than the standard ΛCDM framework. The study, which has not yet completed peer review, provides a testable forecast: upcoming precision surveys should show the dark-energy equation-of-state parameter drifting away from −1 within the next decade. Separately, a team at the University of Portsmouth, led by cosmologist Indranil Banik, reports evidence that the Milky Way may sit near the centre of a vast cosmic void about two billion light-years across and 20 percent less dense than the cosmic average. Presented this week at the Royal Astronomical Society’s National Astronomy Meeting, the analysis of baryon acoustic oscillation data finds the void scenario roughly 100 million times more likely than a homogeneous model, offering a potential solution to the long-running “Hubble tension” over the universe’s current expansion rate. Taken together, the two studies add momentum to re-examining the standard cosmological model. While each remains controversial and awaits independent confirmation, both propose that the universe may be less uniform—and its ultimate fate more finite—than long assumed.