Some scientists say that our universe could be only one side of the coin. The other side is something they call “the anti-universe.” It’s basically a hypothetical mirror universe where time goes backwards.
Scientists believe there is a mirror universe
But how exactly did the scientists come to this conclusion? A new study on the subject focuses on the three most important symmetries scientists have found in nature: charge, parity and time.
Charge basically dictates that if you flip the charge of a particle involved in an interaction to its opposite, you will get the exact same interaction. Parity then dictates that if you look at the mirror image of an interaction, you will see the same result in the reflection. Finally, time dictates that running any interaction backwards in time will make it look the same. This fundamental idea is known as CPT symmetry for short.
Like Life sciences notes, most physical interactions obey at least most of these symmetries most of the time. However, there are a few infractions. Despite these outliers, scientists have never found interactions that ignore all three symmetries at the same time.
In this new paper, however, the scientists posit that this symmetry is not just about actions that take place in the universe. Instead, it applies to the entire cosmos. But how do we go from talking about symmetry in the universe to proposing a mirror universe? This is where things get really interesting.
balance in everything
If you’ve ever watched any of star wars movies, then you’ve probably heard people talk about Jedi and Sith balancing each other out. Fantasy films also speak of the precarious balance between good and evil. It is this fundamental idea of balance that led scientists to believe in the existence of a mirror universe.
Extending the idea of CPT symmetry to the entire cosmos, scientists argue that we cannot see our universe as a whole. Instead, our universe is simply a part – a charge reversal, so to speak. As such, there must be more, a mirror universe that resembles our own, except it goes back in time to account for the CPT.
Not only would a universe obeying the CPT create balance, but it would also create additional discoveries around dark matter and everything as a whole.
What does a CPT-obedient universe look like?
Scientists say that a universe obeying the CPT would allow the universe to expand naturally instead of relying on a period of rapid expansion – the Big Bang. This alone could open the door to a variety of viable alternatives beyond the Big Bang theory.
Launching a mirror universe would also open the door to additional neutrinos. These particles always appear as left-handed, whereas all other particles in the universe consist of both left-handed and right-handed varieties. According to scientists, this could be another clue to the existence of a mirror universe.
Scientists say these right-handed neutrinos are unlikely to be visible. Instead, they would be invisible particles closer to dark matter, which manifests its existence through interactions with gravity. All in all, it’s an interesting idea and infinitely more complex than you might think at first glance.
But proving its existence will not be easy. Because our mirror universe exists before the Big Bang, there is no way for us to visit it. However, scientists can dig deeper through testing. Who knows, maybe we’ll see more research on this in the future.