Lquantum physics is really weird. According to its laws, you can for example have a cat that is both dead and alive until you can observe it directly. We can also have particles which interact independently of the distance which separates them, or even particles which pass through two holes at the same time. With its rules, it is impossible to know simultaneously the speed and the position of an electron, it is necessary to choose. Einstein himself was bothered by some of its aspects, including the fact that items were based on probability, which caused him to utter the famous phrase “god does not play dice”.
While quantum physics is a good description of what happens at the microscopic level, it sometimes seems difficult to make it coincide with what happens at higher scales: nothing prevents knowing both the speed of a rally car and its position on the road! So where do the “mysterious” quantum phenomena come from? Parallel worlds, of course. In any case, this is the theory just imagined by physicists from Griffith University (Australia), who describe it in an article which has just appeared in the journal Physical Review X.
According to them, there would be a huge, but finite, number of “classical” universes like ours, and the interaction between these universes would generate quantum phenomena. They cite for example the tunnel effect, which allows a particle to cross a barrier of potential without having the energy required to do so, or the energy of a vacuum, which would be “direct consequences of the mutual repulsion between these parallel worlds. These interactions would therefore explain “everything that is bizarre in quantum mechanics”. Overall then, parallel universes, instead of developing independently, would influence each other.
Parallel universes are not independent.
While parallel worlds are one of the favorite subjects of science fiction literature, they are also the subject of very serious study by science, especially in the light of quantum physics. As early as 1957, Hugh Everett explained that the universe included all the states defined by quantum mechanics, and that it was the observer who saw only one possibility. To put it simply, the fact of interacting with reality made him “choose” a path, without the others ceasing to exist simultaneously.
So what's new about what the Griffith University team has to offer?
“In the well-known theory of multiple worlds, each universe separates into a bunch of new universes each time a quantum measurement is taken,” explains Professor Wiseman, one of the authors of the article. “All possibilities are therefore realized: in some universes, the asteroid that killed the dinosaurs missed Earth. In others, Australia was colonized by the Portuguese. But critics question the reality of these other universes, since they do not influence our universe at all. On that note, our theory of “multiple interacting worlds” is completely different, as the name suggests ”.
The “theory of multiple interacting worlds” can be summed up in three points:
The universe we know is just one of a gigantic number of worlds. Some are almost identical to ours, while most are very different.
All of these worlds are as real as each other, exist permanently over time, and have precisely defined properties.
All quantum phenomena arise from a universal force of repulsion between “neighboring” (ie similar) worlds, which tends to make them more dissimilar.
For Dr. Hall, co-author of the article, this theory could create the extraordinary possibility of testing the existence of other (parallel) worlds. And that wouldn't be science fiction.
