© William Horton, William Horton Photography
Every once in a while, it’s worth pausing for a second and giving thanks to the many, slightly different versions of you that exist in parallel realities. It is these alternate selves that help keep these universes in balance.
At least, that’s the case if you subscribe to the many-worlds interpretation of quantum theory. First proposed more than 65 years ago, the idea is that reality is constantly splitting along parallel paths due to subtle interactions at the level of quantum particles. While it may boggle the mind, it also smooths over devilishly difficult problems in physics, and is therefore believed to be true by many clear-eyed physicists.
But now this strange idea may face a major challenge, thanks to physicists Sandu Popescu and Daniel Collins of the University of Bristol, UK. They initially set out to solve a 100-year-old puzzle in quantum theory, but ended up undermining the idea of parallel universes. “We’ve basically demolished one of the arguments,” says Collins.
It may seem like an unstable development, but it can actually be shown to be an arm of quantum theory. Already, the work of Popescu and Collins is helping to resolve other long-standing quantum paradoxes and, some theorists believe, represents a new way of thinking about the cosmos as a unique quantum reality constructed from within. “This is something deep and new. I think it could be really important,” says Nicolas Gisin, who researches…
