According to the study published in the Journal of Cosmology and Astroparticle Physics, the universe — currently 13.8 billion years old — will continue expanding for about another 11 billion years until it reaches its maximum size (roughly 1.7 times its current size). Then, the expansion will stop, and the universe will enter a contraction phase, shrinking toward a single, extremely dense and hot point — much like how it began with the Big Bang.
Henry Tye, the lead researcher from Cornell University, explained that this scenario is based on new observations suggesting that dark energy — which makes up over 70% of the universe — may not be constant, as previously believed, but variable. According to the model, hypothetical particles known as axions initially drove the universe’s expansion but are gradually losing their influence, allowing gravity to pull the universe back into collapse.
Scientists believe the contraction phase would occur faster than the expansion phase, as gravity and matter density accelerate, pulling all galaxies, stars, and planets back into an ultra-dense, fiery singularity — effectively reversing the Big Bang’s course.
However, the researchers emphasized that this scenario is not a “prophecy,” but rather a scientific hypothesis that depends on the validity of current observations about dark energy, whose exact nature remains unknown.