A recent cosmic ray detection experiment has discovered particles that may originate from a parallel “realm”—one that was also born from the Big Bang.

Scientists used a giant helium balloon to carry NASA’s Antarctic Impulsive Transient Antenna (ANITA) into the upper atmosphere above Antarctica, where the cold, dry air creates an ideal environment with minimal radio interference—something that could otherwise distort collected data.

That’s when they detected a stream of high-energy particles coming from space.

Low-energy subatomic neutrinos, with almost no mass, can pass straight through the Earth, but higher-energy objects are blocked by the planet’s dense matter.

This means that high-energy particles can only be detected when coming down from space—but the team’s ANITA antenna detected heavier particles, known as “tau neutrinos,” going up from the Earth toward space.

This discovery suggests that the particles are actually moving backward in time, which could be considered evidence of a parallel universe.

Peter Gorham, a physicist at the University of Hawaii and a researcher on the ANITA project, stated that the only way for the “tau neutrino” to behave this way is if it transforms into another type of particle before passing through the Earth and then changes back.

Gorham, co-author of a study conducted at Cornell University describing this bizarre phenomenon, said that he and his colleagues had observed many of these “impossible events”—phenomena that some remain skeptical about.

“Not everyone is satisfied with that hypothesis,” he admitted.

The simplest explanation for this phenomenon is that at the moment of the Big Bang 13.8 billion years ago, two universes were formed—our universe and a mirror universe (from the perspective of the first) where time flows in the opposite direction.

Of course, if there were intelligent life in such a parallel universe, they would see us as the universe where time runs backward.