Mother Nature Network has the article Parallel worlds exist and interact with our world, say physicists.
Wiseman and colleagues have proposed that there exists “a universal force of repulsion between ‘nearby’ (i.e. similar) worlds, which tends to make them more dissimilar.” Quantum effects can be explained by factoring in this force, they propose.
Whether or not the math holds true will be the ultimate test for this theory. Does it or does it not properly predict quantum effects mathematically? But the theory is certain to provide plenty of fodder for the imagination.
Many a fanciful theory has fallen flat on the test of whether or not the math holds true. Many scientists would probably not publish a theory where they have not already shown that whatever math they had tried so far has been proven to hold true.
It is an intriguing theory which these scientists have admitted has been around since 1957. It would be nice if such a theory could explain the mysteries of quantum entanglement. Quantum entanglement has been experimentally shown to exist, but so far I don’t think scientists have the foggiest idea of the mechanism that makes it work.