Invisible matter called dark matter remains one of the greatest mysteries in cosmology. Perhaps this strange matter originates from a “dark mirror universe” that has been connected to our own since the beginning of time, according to a new study. What if the world of dark matter is our mirror, with only a few rules broken? A new theory suggests this could explain why dark matter appears so massive but invisible.

Dark matter is a mysterious, unknown substance that appears to make up the majority of all mass in the universe; For every 2 pounds (1 kilogram) of ordinary matter, there are about 10 pounds (5 kg) of dark matter. It does not interact with light or ordinary substances. The only way scientists can detect it is through subtle gravitational effects on normal matter, such as the movement of stars in galaxies and the growth of supermassive structures in spacetime.

Because matter and dark matter operate by different rules, it might be easy to think that one would completely dominate the other. However, despite their vastly different properties, the amount of normal matter and dark matter is still the same. It seems like a strange coincidence. To explain this, scientists suggested that there may be a hidden connection between them. They published their research on January 22 in the preprint journal arXiv.

Researchers have suggested that every physical interaction in normal matter has a mirror in the dark matter world. According to the researchers, this would be a new kind of symmetry in nature, connecting the normal world and dark matter.

This symmetry helps explain why dark matter and ordinary matter are present in roughly the same amount.

In the article, researchers point out another strange coincidence. In normal matter physics, a neutron and a proton have almost the same mass, which allows them to bond together and form stable atoms. If the proton were even slightly heavier, it would be completely unstable and would decay in just a few minutes, making it impossible for atoms to form. In this imaginary scenario, the universe would be left with a sea of ​​free-floating neutrons.

Perhaps, the researchers suggest, this imaginary fractured universe could be a reality in a mirror version of the dark matter in our universe. A special combination of physics caused the proton to have roughly the same mass as the neutron; Perhaps in the dark matter mirror this combination of physics worked differently, causing the “dark proton” to evaporate, leaving behind a sea of ​​“dark neutrons” (what we define as dark matter).

Although this proposed mirror model allows for a lot of interaction between dark matter particles (dark atoms, dark chemistry, and the dark periodic table of elements), the researchers noted that there cannot be too many interactions. If dark matter interacts with itself strongly, it will tend to clump together much more than scientists thought. So most dark matter should be relatively simple; a sea of ​​free-floating neutral particles.

These additional interactions, which would be a dark mirror of our chemical world, could allow future scientists to test this theory. In the early universe, normal matter underwent nucleosynthesis when the first elements were formed in the nuclear plasma. If this new idea is correct, mirror nucleosynthesis also occurs in dark matter. In those chaotic early days, channels may have been opened between the two worlds that allowed them to influence each other.

By carefully measuring the rate at which elements are formed—something a new generation of cosmological observatories hope to do—scientists can find evidence of one of these channels and study the dark, mirror-like universe.