Imagine waking up after death and living out your old age, until you grew young enough to have a career, and hoped someday to go to college. This is what life might be like in the “mirror” universe, the exact opposite of ours. According to two teams of physicists, our universe may have a twin where time moves backward.
Of course, this is all just theoretical. But the theory answers some fundamental questions physics has been wrestling with for quite some time. One is, if the universe during the Big Bang was made of equal parts matter and antimatter, where’s all the antimatter?
Paul Dirac first proposed antimatter in 1928. Since then, physicists have found a wide range of antiparticles. These are present during high energy collisions in other places in the universe and also within particle accelerators, such as the large hadron collider at CERN.
In a 1964 experiment, which won them the Nobel Prize 16 years later, James Cronin and Val Fitch proved that you cannot have an antimatter universe for the simple reason that the weak nuclear force violates this model. For a while that was that.
Then in 2004, two scientists at Caltech, Professor Sean Carroll and his graduate student Jennifer Chen, revived the mirror universe theory, by trying to address another fundamental physics question, why does time only move in one direction?
Experiments at the HLC at CERN have shown antimatter. But it’s eerily absent in nature. Getty Images.
Through the course of their investigation, they ended up creating a model of the Big Bang which shoots outward in two opposite directions. In our universe, everything is made up of matter, while in the mirror universe, its antimatter.
As time moves forward in one direction in one universe, it moves backward in the other. But from the mirror universe, time would appear to be moving backwards in ours, which begs the question, who is actually in the backwards universe, us or them?
Generally speaking, when we talk about time, we consider the Second Law of Thermodynamics and in particular, entropy. This is the amount of disorder in a system which will eventually break it down, be it an engine,…
