Is There a Parallel Universe?
Time, as we know it, moves from the past to the future irreversibly. But now, an international trio of theoretical physicists suggests that there’s more than one future. They say that two parallel universes were produced by the Big Bang. One, which moves forward in time, and another where time moves backwards. These findings were published in Physical Review Letters in October this year.
In the 1920s, British astronomer Arthur Eddington created the term “arrow of time”, which describes the asymmetrical, one-way direction of time. Many physicists accept that time moves in the direction of increasing entropy (disorder, randomness, and chaos) in order to approach some equilibrium.
According to this theory, things tend to fall apart. If that’s the case with us, then our universe must have begun in a low-entropy, highly ordered initial state.
But why was there this rare moment of low entropy before? APS Viewpoint explains that one century-old idea developed by Austrian physicist Ludwig Boltzmann suggests that our visible universe is a temporary, statistical fluctuation that affects only a small portion of a much larger equilibrium system.
But there’s also another possible explanation. Oxford’s Julian Barbour, Tim Koslowski from the University of New Brunswick, and Flavio Mercati of the Perimeter Institute for Theoretical Physics are introducing a new arrow of time, one that’s based on gravity.
“Time is a mystery. Basically, all the known laws of physics look exactly the same whichever way time runs.”