  In this paper we address the question of whether it is possible to obtain
evidence that we are in a superposition of different worlds, as suggested by
the relative state interpretation of quantum mechanics. We find that it is
impossible to find definitive proof, and that if one wishes to retain reliable
memories of which world one was in, no evidence at all can be found. We then
show that even for completely linear quantum state evolution, there is a test
that can be done to tell if you can be placed in a superposition.
