Claiming, then, that multiverse theories are unscientific because they are unfalsifiable is to reject them simply because they do not live up to an arbitrary standard that no scientific theory of any kind has ever met. Claiming that no data could ever force the rejection of a multiverse theory is merely stating that a multiverse theory is just like any other theory. And claiming that there could never be any observable evidence in favor of a multiverse theory is to forget Einstein’s admonition that “it is the theory which decides what we can observe.”
