Two independent teams of physicists have been examining the flow of time in the Universe, and they have proposed that approximately 14 million years ago, the Big Bang could have given rise to a reverse mirror universe , where time is moving in the opposite direction. : instead of going forward, it moves backwards.
Thus, from his particular perspective, our time would flow from the future to the past: “ Time is not something that pre-exists . From the direction and flow of time we have to deduce what is happening in the Universe. When we see it this way, it is natural to say that time begins at that central point and flows in opposite directions, ”explains Julian Barbour, a physicist at the University of Oxford (UK) to Quartz magazine.
In fact, if time were to flow backwards, none of the fundamental laws of Physics would be affected and the equations that best define our universe (Newton’s Universal Gravitation, Einstein’s Theory of Relativity, Maxwell’s electrodynamics, quantum mechanics) work perfectly whether time is flowing backwards or forwards.
Two teams of physicists have thus arrived at similar results using a different particle model. The first, formed by Julian Barbour and other collaborators, discovered that, thanks to gravity, particles could expand in various directions, so time could also move in both directions , in a universe where the possibility of flowing forward or back in time was equally acceptable.
The second, -whose work has been published in New Scientist- , Sean Carrol, of the California Institute of Technology, and Alan Guth, of the Massachusetts Institute of Technology (USA) conceived a fine cloud of particles and arranged it in a theoretical infinite universe. As he did so, two different time arrows spontaneously emerged : one forward and the other, after remaining huddled in the center of the cloud, just in the opposite direction, like two points on the arrow of time.
In this way, if an arrow of time arises in one direction, the same will happen in the opposite direction, regardless of its starting point. According to the researchers, this model reveals that all particles move outward, that entropy grows without limit, and that “time zero” would be the lowest entropy point.
