According to John von Neumann’s interpretation of QM, consciousness is why the wave function collapses. Copenhagen is on the same general idea, but does not mention it that categorically. Multiverse interpretation of QM says there is no wave function collapse, therefore the observer or consciousness has no role in it. All probabilities of a particle exist in other alternative universes. So we come to the following scenarios. Either all the other alternative universes exist already. This would make sense in Einstein’s universe were all spacetime is a continuum and therefore all is already determined from the beginning (no real choices); or The observer by observing a possibility of a particle, chooses an alternative universe, many other alternative universes split from this original act. In this scenario, the observer plays a bigger role than in the Copenhagen or John von Neumann interpretation. In this interpretation the observer does not collapse a wave function, it creates alternative universes. Which is more crazy?