Despite them, many scientists consider that they are likely to be real, so they continue to search for information through tests around the world.Through the Antarctic Impulse Transient Antenna (ANITA), Peter Gorham and several experts have found particles not belonging to our universe in an Antarctic rapid radio burst (FRB) detection experiment, the flawless location to capture this type of signs.
In a scenario that sounds straight out of science fiction, a team of NASA scientists may have detected evidence of a parallel universe - where time runs in reverse.
A constant "wind" of high-energy particles, however, constantly arrived on Earth from outer space.
For the study, the experts used a purpose-built balloon to carry the antenna high above Antarctica to scan for high-energy particles coming down from space.
Principal ANITA investigator Peter Gorham, an experimental particle physicist at the University of Hawaii, suggested that the only way the tau neutrino could behave that way is if it changed into a different type of particle before passing through the Earth and then back again.
Describing the odd phenomenon, he noted that his fellow researchers were sceptical about many of such "impossible events".
Not everyone, however, was comfortable with the hypothesis.
CNET notes that the initial report claiming that scientists found evidence of a parallel universe appears on New Scientist in an article behind a paywall that may have caused subsequent reports to be based entirely on the opening paragraphs, which are visible for free. That led to the formation of two universes - ours and one that "from our perspective is running in reverse with time going backward". Scientist Ibrahim Safa spoke on the experiment and the results, saying, "We're left with the most exciting or most boring possibilities".