The solution lies in the relationship between mass and scale, a concept formalized by Roger Penrose in his Conformal Cyclic Cosmology (CCC). Physical dimensions (size and time) are only measurable when mass is present to provide a “ruler.”
- Total Mass Decay: As the universe reaches its final stage, all matter – including dark matter and black holes – must eventually decay into massless radiation. In a purely massless state, the concepts of “big” and “small” disappear because there is no physical scale to define them.
- Geometric Identity: In a state of total scale invariance, a universe that is infinitely large is mathematically indistinguishable from one that is infinitely small.
- The Phase Transition: This “Conformal” symmetry allows the stretched, empty geometry of the future to map perfectly onto the dense, hot geometry of a new past. The geometry itself performs a “factory reset” by making the entropy of the previous cycle physically irrelevant to the new one.