make the following device: a stern-gerlach device oriented to the x axis, where +x particles enter a stern gerlach device oriented to the z axis. If a particle comes out of the +z end, the device shoots you in the head, otherwise it doesnt. Its like quantum russian roulette. Anyway, the thing that MWI has that other interpretations don't is that unobserved measurements actually exist in other universes. Since we can only be conscious of a universe we are alive in, if out universe splits, we can only go into one of the child universes where we are alive. Therefore, if we use this device many times, we could "prove" to arbitrary error that MWI is true. The problem with this proof is that we would only be able to prove this to ourselves and the lucky few universes where we remain alive. In most other universes we would be dead (dieing wouldn't disprove MWI tho). Any thoughts on this?