The challenge that the multiverse poses for the idea of an all-good, all-powerful God is often focused on fine-tuning. If there are infinite universes, then we don’t need a fine tuner to explain why the conditions of our universe are perfect for life, so the argument goes. But some kinds of multiverse pose a more direct threat. The many-worlds interpretation of quantum physicist Hugh Everett III and the modal realism of cosmologist Max Tegmark include worlds that no sane, good God would ever tolerate. The theories are very different, but each predicts the existence of worlds filled with horror and misery.
Of course, plenty of thoughtful people argue that the Earth alone contains too much pain and suffering to be the work of a good God. But many others have disagreed, finding fairly nuanced things to say about what might justify God’s creation of a world that includes a planet like ours. For example, there is no forgiveness, courage, or fortitude without at least the perception of wrongs, danger, and difficulty. The most impressive human moral achievements seem to require such obstacles.
Still, many horrifying things happen with nothing seemingly gained from them. And, Everett’s many-worlds and Tegmark’s modal realism both seem to imply that there are huge numbers of horrific universes inhabited solely by such unfortunates. Someone like myself, who remains attracted to the traditional picture of God as loving creator, is bound to find such consequences shocking, and will wonder just how strong the evidence is for these theories.
The many-worlds interpretation arises from a problem in quantum mechanics. The Schrödinger equation, the fundamental law of quantum theory, is a description of the evolving states of particles. But some of the states it predicts are combinations—“superpositions”—of seemingly incompatible states, such as a coin landing both on heads and tails. We can wonder: What explains the fact that we don’t ever observe the combined incompatible states, but only observe coins that land on heads or tails? One answer many theorists provide is that there is more going on than the Schrödinger equation describes. They add a process called “the collapse of the wave function,” which results in a definite outcome of heads or tails.
But in the 1950s, Everett proposed a bold alternative. His theory has no collapses, but instead holds that all the parts of these combined—or “superposed”—states occur as parts of equally real but relatively isolated worlds. There are some complete copies of the universe in which the coin lands heads, and in others tails. And this applies to all other physical states—not just flipping coins. There are some universes where you make the train and get to work on time, and others where you don’t, and so on. These slight differences create multiple overlapping universes, all branching off from some initial state in a great world-tree.
Everett’s many-worlds and Tegmark’s modal realism both seem to imply that there are huge numbers of horrific universes.
Old-fashioned quantum theory assigns a tiny likelihood to things going really badly in the future. It also implies that, from any point in our actual past, things could have gone much worse than they actually did. Since the many worlds interpretation takes these possibilities as actual occurrences, it predicts that there are branching universes in which things do go as awfully as possible.
For example, whenever there is a minute chance of a catastrophe that leaves all human beings utterly miserable but just barely healthy enough to reproduce, there is a branch in the world-tree in which this sorry state of affairs actually happens, generation after generation. So there are worlds in which the emergence of the human race proves to be an unmitigated tragedy—or so it seems…