Cosmic Fate Rewritten: Could the Universe End in a Big Crunch
A Cornell-led analysis proposes the expansion of the universe could be temporary and eventually reverse if the cosmological constant is negative, driven by an ultralight axion field. The model places the universe’s total lifespan at about 33.3 billion years, with a slow crunch starting in roughly 11 billion years and final collapse about 8 billion years later (around 19–20 billion years from now). If dark energy’s behavior continues to deviate from a true constant, this Big Crunch scenario could hold; upcoming surveys and missions (Euclid, Rubin Observatory, SPHEREx) are expected to refine measurements and test the idea.
