I don't know any physics, but I know some people who do. One of them, for example, won the Fermi prize. I was always bothered by the idea that something could be in two different places at the same time, and I was told that a better way to think of it is that the probability that a particle is in one place is the same as the probability that it is in the other. The Heisenberg uncertainty principle promises that there is a positive number p such that the product of a particle's velocity (well momentum actually) times the possible change in it's position is greater than p. If the particle is cold (very cold) the first number is small so that the possible change in the particle's position must be large in order for the product of the two numbers to exceed p. Thus if a particle is cold, you don't know where it is.
None of this rules out parallel universes, which are explained to people who can follow him by John Baez. BTW the distance between John Baez and Joan Baez is much greater than one letter would suggest.