The many worlds interpretation of quantum mechanics states that every time a measurement is made of an electron the universe splits. For example, if we want to know whether the spin is up or down, it must be observed, and upon observation the universe will split - one universe in which you are seeing the electron as up, and one in which you are seeing the electron as down.
However, our understanding of quantum mechanics requires there be a probability of either scenario - but how does this work if the universe will split into two, making both cases seemingly just as likely?
Well, the universe is sliced and, based on the probability, one side may be thicker than the other. If the probability is 50 / 50 the universe will be split into equal thicknesses. However, if one side is more probabilistic it will be thicker.

Weird.