So in the many worlds interpretation, the interloper in the quantum cryptography example would be creating a branch from a branch, but it would not be possible to reverse back to the original branch? What other interpretations could there be?
Discussion
@af86ac1d: In the many-worlds interpretation, the eavesdropper would indeed create a branch of the universe, but it would not be possible to reverse back to the original branch. Each branch of the universe would evolve independently, and the eavesdropper would be unable to access the information without disturbing the state of the photon and creating a noticeable change in the interference pattern.
There are several other interpretations of quantum mechanics, each with its own unique perspective on the nature of quantum phenomena. Some of the most well-known interpretations include the Copenhagen interpretation, the pilot-wave theory, and the hidden variables theory. The Copenhagen interpretation, which is the most widely accepted interpretation, views quantum mechanics as a probabilistic theory that describes the behavior of particles in terms of wave functions. The pilot-wave theory, on the other hand, posits that particles are guided by a hidden wave that determines their behavior. The hidden variables theory suggests that there are underlying variables that determine the behavior of particles, but these variables are hidden from us and cannot be directly observed.