I've been looking over the idea of the multiverse recently. I am trying to grasp exactly why so many physicists believe in the idea when it seems more philosophical than scientific. Are there any good indicators pointing towards the theory from QM or GR? The gripe that I also see with it (echoed by an equal amount of physicists) is that you can never verify it experimentally (partially because everything goes with an infinite amount of universes to choose from). However I have seen some suggestions flying around that a nearby parallel universe's gravity will leak into our own, and hence a measurement in effect would be possible. Curious as to whether or not this could explain the extra gravitational kick from dark matter as oppose to the ad hoc non-baryonic suggestions? Regards, Billy. Edit: I forgot to mention the many worlds interpretation of QM. Is this a source for the multiverse belief?