If, however, there's an infinite number of different universes with different laws and parameters, then even astronomically improbable universes will be among that infinite array. Thus, as amazing as our world is, it pretty much had to exist, given the multiverse. Nevertheless, as philosopher Vincent Torley points out in a lengthy treatment of the multiverse at Uncommon Descent there's a perplexing difficulty for the naturalist who clings to the multiverse in order to avoid falling into theism. If the multiverse exists then not only does the improbable become certain, but so, too, does anything that is physically possible, including miracles.
The irony is that the naturalist rejects the miraculous because he rejects belief in the existence of God, but in order to sustain his non-belief in God he relies on a hypothesis that makes miracles certain to occur.
Naturalism sees the universe as invariant. That is, the laws of physics hold everywhere and always. They're inviolable. Thus, miracles, for the naturalist, are impossible, but as Torley points out, in a multiverse there should be universes in which the laws of physics fluctuate episodically, thereby permitting anomalous events like miracles, and that these universes should be far more common than uniformitarian worlds in which the laws are invariant.
[B]ecause multiverses allow laws to vary bizarrely on rare and singular occasions, and because not all such variations are fatal to life, we can conclude that a life-permitting universe is far more likely than not to experience anomalous events (which some might call miracles), and that a life-permitting universe in which Biblical miracles occur is still more likely than one in which the laws and physical parameters of Nature are always uniform.The naturalist who embraces the multiverse has a another problem in addition to the problem with miracles. Darwinian evolution is predicated on uniformitarianism, the belief that the laws of physics never change, but if there's a multiverse, of which we are a part, then uniformitarianism becomes highly improbable. Torley says:
Thus [the] belief that we live in in a universe where Biblical miracles occurred will still be more rational than the modern scientific belief that we live in a universe whose laws are space and time-invariant, because [these] universes are more common in the multiverse than law-invariant universes.
And since the argument for Darwinian evolution is based on the assumption that the laws and parameters of Nature do not vary, it follows that if we live in a multiverse, then our own universe is infinitely more likely to be one in which the miracles of the Bible occurred than a uniformitarian one in which life evolved in a Darwinian fashion.What a pickle. The naturalist rejects miracles and accepts Darwinian evolution (i.e. that evolution is a completely natural process with no intelligent input from a non-natural mind) largely because he rejects the existence of God. He buttresses that rejection by also accepting the idea of the multiverse as an answer to the argument for God's existence based on cosmic fine-tuning, but by accepting the multiverse he pretty much has to give up the underlying assumption of Darwinism (uniformitarianism) and also his opposition to miracles. In other words, he can't have it both ways.
... there will still be a number of possible universes in the multiverse, in which life pops into existence in the manner described in Genesis 1, and where living things just happen to exhibit the striking traits predicted by Darwinism, whereas there is (by definition) only ONE way for a given set of laws and parameters NOT to vary: namely, by remaining the same at every point in space and time.
The problem [for the naturalist] is that the uniformitarian requirement that the laws and parameters of Nature are the same at every point in space and time – which is rather like hitting bull’s eyes again and again and again, for billions of years – is inherently so very unlikely, when compared to “singularism” (the hypothesis that the laws of Nature undergo slight, short-lived or local fluctuations)...
Thus in a multiverse scenario, uniformitarianism becomes the albatross around the neck of Darwinism: no matter how many of Darwin’s predictions scientists manage to confirm, the sheer unlikelihood of the hypothesis that we live in a universe whose laws never vary renders Darwinism too unlikely a theory to warrant scientific consideration.
Here's another example of how embracing the multiverse leads to all sorts of unintended consequences for the naturalist. Cosmologist Sean Carroll, an atheist, has been quoted as arguing that the multiverse hypothesis, though it does not meet to the standard criteria of a good scientific theory (i.e. it's not falsifiable or testable) nevertheless should be accepted as legitimate science. He writes:
Modern physics stretches into realms far removed from everyday experience, and sometimes the connection to experiment becomes tenuous at best. String theory and other approaches to quantum gravity involve phenomena that are likely to manifest themselves only at energies enormously higher than anything we have access to here on Earth. The cosmological multiverse and the many-worlds interpretation of quantum mechanics posit other realms impossible for us to access directly. Some scientists, leaning on Popper, have suggested that these theories are non-scientific because they’re not falsifiable.This reminds me of a passage from William James who said that, "any rule of thought which would prevent me from discovering a truth, were that truth really there, is an irrational rule."
The truth is the opposite. Whether or not we can observe them directly, the entities involved in these theories are either real or they are not. Refusing to contemplate their possible existence on the grounds of some apriori principle, even though they might play a crucial role in how the world works, is as non-scientific as it gets.
Carroll wants to apply James' assertion to science in the belief that it's not reasonable to restrict science only to conjectures about entities whose existence can be tested. Thus, the multiverse should be considered legitimate science because it's an entity that's either real or it's not, and "refusing to contemplate [it's] possible existence on the grounds of some apriori principle, even though [it] might play a crucial role in how the world works, is as non-scientific as it gets."
Very well, but wouldn't this same standard also apply to God? Wouldn't it also apply to Intelligent Design which is banned from public school classrooms because it allegedly can't be tested and is therefore not regarded as a genuine scientific theory by such experts on the philosophy of science as Judge Jones?
Carroll wants to make the multiverse a viable scientific option because it gives him an out when confronted by the phenomenon of cosmic fine-tuning, but in order to include the multiverse hypothesis in the field of legitimate scientific inquiry he has to open up the domain of science to include conjectures about the existence of God, which is the very thing he's trying to avoid.