Although we experience time in one direction—we all get older, we have records of the past but not the future—there’s nothing in the laws of physics that insists time must move forward.
In trying to solve the puzzle of why time moves in a certain direction, many physicists have settled on entropy, the level of molecular disorder in a system, which continually increases. But two separate groups of prominent physicists are working on models that examine the initial conditions that might have created the arrow of time, and both seem to show time moving in two different directions.
When the Big Bang created our universe, these physicists believe it also created an inverse mirror universe where time moves in the opposite direction. From our perspective, time in the parallel universe moves backward. But anyone in the parallel universe would perceive our universe’s time as moving backward.
The Janus point
The first model, published a little over a year ago in Physical Review Letters, argues that that one of the basic implications of Newton’s theory of gravity creates the conditions for time to move in a certain direction. Julian Barbour from the University of Oxford, Tim Koslowski from the University of New Brunswick and Flavio Mercati from the Perimeter Institute for Theoretical Physics, argue that for any confined system of particles—a self-contained universe such as our own, for example—gravity will create a point when the distance between particles is minimal.
When the particles then expand outwards, they do so in two different temporal directions.
Read full article at : It’s possible that there is a “mirror universe” where time moves backwards, say scientists