Scientists propose the existence of a symmetrical version of the universe with oppositely charged particles and time running backwards.
Researchers from the University of Waterloo (Canada) have hypothesized about an “anti-universe,” a parallel universe that operates similarly to the one humans inhabit, but where time flows in reverse, prior to the occurrence of the Big Bang.
This idea suggests that the original universe was small, hot, dense, and uniform to the extent that time runs in two symmetrical directions. If correct, this hypothesis could explain the origins, the expansion process of the universe, and the existence of dark matter.
Three Factors of the Symmetrical Universe
To explore this hypothesis, scientists have identified three important symmetrical components of nature: charge (if the charge of interacting particles is reversed, they still interact in the same way), parity (looking at the reflection of an interaction, they remain in a similar state), and time (the interactions are the same even when time runs backward).
The symmetrical universe operates similarly to the universe inhabited by humans. (Image: New York Post).
Most physical interactions adhere to this type of symmetry, meaning discrepancies can occur. However, physicists have never observed all three symmetrical components deviating simultaneously. If we take all observed interactions in nature and reverse the charge, look through reflections, and run time backward, they will function identically.
According to Live Science, this type of symmetry is called CPT symmetry, where C stands for “charge,” P stands for “parity,” and T stands for “time.”
In a study published in the Annals of Physics, scientists proposed expanding the application of CPT. Typically, this symmetry is reserved for interactions (the forces and fields that constitute cosmic physics). However, the research team suggested applying CPT to the entire universe. If CPT symmetry is expanded, humanity’s perspective on the universe would change dramatically.
To validate the hypothesis, the existence of a parallel universe with oppositely charged particles, reflecting the entire image and running time backward compared to the universe humans inhabit, is necessary. By combining these factors, the two universes would conform to the concept of CPT symmetry.
Modeling the Symmetrical Universe
If a symmetrical universe exists, it could expand and fill with matter particles in a natural way without requiring rapid inflation events. While there is evidence that such phenomena occurred after the Big Bang, the theories surrounding them are quite limited. This has led to numerous hypotheses about how the universe expands over time.
The CPT symmetrical universe also introduces various types of neutrinos, the “mysterious” particles that carry no charge and have a mass close to zero. There are three known types of neutrinos: electron, muon, and tau. Interestingly, they all “rotate left-handedly” (in terms of spin relative to motion), while known physical particles include both left-handed and right-handed types. Consequently, physicists have long questioned whether there are “right-handed” neutrinos.
The symmetrical universe will have time running backward compared to our universe. (Image: The Next Web).
The CPT symmetrical universe would require at least one type of “right-handed” neutrino. These neutrinos would be nearly invisible in physical experiments but would influence the universe through gravitational forces.
Thinking broader, the type of particle that pervades the universe and only interacts via gravity closely resembles the characteristics of dark matter. If a symmetrical universe exists, we could gain a clearer understanding of dark matter through “right-handed” neutrinos.
Nevertheless, humans will never be able to reach the symmetrical universe because it exists “behind” the Big Bang, prior to the formation of the universe we inhabit. However, researchers have constructed models to test the hypothesis.
After observing the research model, scientists have proposed several viewpoints. Firstly, they believe that the three types of “left-handed” neutrinos are actually Majorana particles, a fermion and also its own antiparticle (particles with the same mass and physical parameters but opposite in direction). However, physicists have yet to determine whether neutrinos possess antiparticle properties.
The “anti-universe” hypothesis could help humanity better understand dark matter. (Image: Getty Images).
The research team also predicts that one of the neutrino types has no mass. Currently, they can only place an upper limit on the mass of neutrinos. If they can accurately measure and find a massless neutrino, the hypothesis of the CPT symmetrical universe would be significantly strengthened.
Ultimately, rapid inflation will not occur in the symmetrical universe model. Physicists believe that this event shook spacetime so violently that it created gravitational waves. Therefore, the CPT symmetrical universe would not exhibit gravitational waves. If research seeking primordial gravitational waves yields no results, it could be a clue suggesting that the symmetrical universe hypothesis is correct.
