Cyclic cosmology, the theory that the universe will collapse back on itself and trigger another big bang, is experiencing renewed scientific interest after decades of skepticism. The idea proposes that our cosmos does not expand forever. Instead, it will eventually reverse direction, compress into a dense state, and restart with a new big bang, beginning an endless cycle of creation and destruction.
New Scientist columnist Leah Crane reports that physicists are revisiting this model as observations challenge the traditional big bang framework. Modern data on cosmic expansion and the universe's age have prompted researchers to reconsider whether cyclic scenarios better explain what we observe.
The concept addresses several puzzles in cosmology. A cyclic universe could resolve the fine-tuning problem, which questions why physical constants appear perfectly calibrated for life. It also sidesteps questions about what existed "before" the big bang by eliminating a singular origin point.
Major obstacles remain. Physicists must explain how entropy, the measure of disorder, behaves across cycles. They also need to demonstrate that a universe can actually bounce rather than collapse permanently.
Recent theoretical work in quantum gravity and string theory has produced more rigorous mathematical models of cyclic scenarios. These advances make the hypothesis testable in ways previous generations could not achieve.