Cyclic model reconciles quantum mechanics and general relativity from "summary" of Endless Universe by Paul J. Steinhardt,Neil Turok
In the search for a theory that unifies quantum mechanics and general relativity, the cyclic model presents an intriguing possibility. This model proposes that the universe undergoes an endless cycle of expansion and contraction, with each cycle lasting trillions of years. During the contraction phase, known as the "big crunch," the universe's contents are compressed to a high energy state before expanding again in a new cycle. One of the key aspects of the cyclic model is that it eliminates the need for a singularity, which is a point of infinite density and curvature predicted by general relativity. By having the universe go through an endless series of cycles, the singularities are avoided, allowing for a smooth and continuous evolution of the cosmos. The cyclic model also addresses the issue of the arrow of time, which is a fundamental asymmetry in the universe related to the increase of entropy. In the cyclic universe, the arrow of time is reset with each cycle, as the universe begins anew with low entropy conditions. This provides a natural explanation for the observed arrow of time in our universe. Furthermore, the cyclic model offers a potential solution to the cosmological constant problem, which is the discrepancy between the predicted and observed energy density of the vacuum. By having the universe go through cycles of expansion and contraction, the energy density is naturally diluted over time, leading to the observed value of the cosmological constant.- The cyclic model presents a compelling framework that reconciles the principles of quantum mechanics and general relativity. By proposing an endless series of cycles without singularities, resetting the arrow of time with each cycle, and offering a solution to the cosmological constant problem, this model offers a new perspective on the evolution of the universe.
