It so happened in the scientific world that scientists have proposed new theories about time, which have one common aspect: they all say that time can flow in the opposite direction in the "mirror universe" - from the future to the past. How much these theories are related to reality, we do not know, and we can hardly touch this mirror universe. Frank Wilczek explained one such theory last week.
This theory may seem crazy to someone, but it is based on solid physical principles. And, of course, we will never be able to experience any other time than our linear model, but in another universe it can indeed flow in the opposite direction.
A group of scientists from the universities of Oxford, New Brunswick and Perimeter last year presented a model according to which Newton's theory of gravitation creates conditions for time to move in a certain direction. The study, published in Physical Review Letters, shows that gravity will create a point where the distance between particles is minimal. After that, these particles will continue in two time directions.
Julian Barbour of Oxford compares the flow of time to a place where a river splits in two and flows in opposite directions. "If the theory is correct, there must be another universe on the other side of the Big Bang, in which the direction of the passage of time will be opposite to ours."
Scientists at the California Institute of Technology and the Massachusetts Institute of Technology have created a different particle model that showed that time moves in two different directions. Their idea is based on entropy, not gravity, and applies to particles in infinite space, not in a closed system, as in the case of the above model.
Their hypothesis could be compared to a bunch of balls on a trampoline. "Half of the balls bounce up, the other half gathers in the center and breaks through the trampoline, creating a mixed pile on the other side," Quartz writes. "And so the Big Bang causes entropy to travel in two different directions, in two different universes."
These theories, which hardly anyone will be able to prove in the near future, are based on classical physics. In the world of quantum physics, nothing is still clear. Instead of two streams of the river, there will be “rather a fountain from which you will receive many streams. Or the streams will flow from the fountain in different directions,”says Barbour.