My layman understanding of the many-worlds interpretation of QM is that if a person had to make a decision between A and B and he chose A, then the universe splits into 2 branches, one where A was chosen and another where B was chosen. First of all, is this correct? Secondly, regarding the many-worlds interpretation of quantum physics, is there any theory that says that these many worlds can actually communicate with each other? If the universe split into 2 because I made a decision to eat chocolate ice cream instead of vanilla, then is there a way that the "chocolate ice cream me" can communicate with "vanilla ice cream me"? Thirdly, could we ever end up with a multiverse scenario like this: In universe X, Alice and Bob exist and they are both at an ice-cream shop that sells only vanilla or chocolate ice cream. They both make their ice-cream choice at the exact same snapshot in time. Alice chooses chocolate and causes the universe to split into X1 (Alice Chocolate universe) and X2 (Alice Vanilla universe). Meanwhile, Bob chooses Vanilla and causes the universe to split into X3 (Bob Vanilla universe) and X4 (Bob chocolate universe). Could we end up in a scenario where X3 and X1 could actually end up being the exact same universe? Or does the theory say that these 4 universes should be distinct?