Ben F. checks back in from the halls of science, with a second installment in his BCC guest series on faith and physics. (Read his first post here.)
I would like to ask a simple question as the basis for this post: Is God a native of our universe? Although I lack any significant polling data, I suspect the gut instinct for most Mormons would be a confident “yes.” After all, Mormon theology emphasizes the shared characteristics between God and his spirit children—we believe he has a physical body that exists somewhere in space and time; we believe that his origin is not so different from our own; and we even believe that we can, with sufficient grace, become like he is. Therefore, it seems only natural that he is from the same place we are from—that is, this universe we find ourselves in. Besides, what would the alternative be? That he is from some sort of parallel universe? That would just be crazy, right?
Maybe not. It turns out that our modern understanding of quantum mechanics and physical cosmology provides reasonably strong theoretical justification for the existence of multiple universes. I would like to suggest that the notion of God originating from and possibly still existing in another universe is not (quite) as far-fetched as it sounds. I do not want to discount the possibility that God’s current place of residence is somewhere within our universe—He has plenty of options, with an estimated 10 to the 20th power (yes, that is 100000000000000000000) habitable planets in our observable universe alone—but in some ways,
parallel universes make it easier to understand certain aspects of God and his creations.
Let’s first consider the current scientific view of the origin of the universe, the standard model of physical cosmology known popularly as the Big Bang theory and more accurately named the ΛCDM model. This theory, which is widely accepted but still lacks some important details, asserts that the universe sprang into existence nearly 14 billion years ago when an enormous surge of energy expanded rapidly from a singularity in spacetime. The Big Bang refers to this first instant of the universe’s
existence. Initially, the universe was so hot that matter existed only as energy, but after the so-called inflationary epoch during which space itself underwent exponential expansion at an extremely rapid rate, the universe cooled enough to allow particles of matter to form and the fundamental forces to decouple from each other through a process called symmetry breaking. As the universe continued to expand and cool, the particles of matter we are most familiar with—electrons, protons, and neutrons—began to form, thereafter combining into neutral hydrogen atoms. Temperature fluctuations from the earliest moments after the Big Bang caused some regions to have higher density than others, resulting in the eventual formation of stars and galaxies. Over the next billions of years, all other elements were synthesized through stellar fusion and supernovae explosions. Around 4.5 billion years ago, a lump of iron and nickel and a handful of other elements formed and fell into orbit around a fairly average star in a fairly average part of a fairly average galaxy, and we now call that place home.
If we accept this theory, which has been highly successful in explaining many features of the observable universe such as the cosmic microwave background and the distribution of large scale structures, then we have to ask the obvious question, “Where was God during the Big Bang?” For that matter, where were we, or more precisely, the eternal intelligences from which we were made? If we insist that God is a native of our universe, then it is hard to find an answer to this question that is consistent with both the ΛCDM model and our understanding of who and what God is. However, at least we could answer one of the long-standing question found in the hymn “If You Could Hie to Kolob”: gods first began to be sometime less than 14 billion years ago.
This is where multiple universes—the multiverse—can come in handy. Although there is certainly no consensus in the physics community about the nature or even existence of alternate universes, various theories are in the process of gaining mainstream status as a result of serious research. There are four major classifications of theoretical descriptions of the multiverse, which I will briefly describe below.
But first, let me be more precise about my use of the word universe. The bounds of our observable universe are set by the most distant objects from which light can have been emitted and reached us since the time of the Big Bang. Because of the ongoing expansion of the universe, this distance is a bit more than just 14 billion lightyears—the most distant observable objects are currently about 40 billion lightyears (4 x 1026 meters) away from us. A sphere of this radius defines our observable universe. Such a sphere is also referred to as a Hubble volume. With this understanding of what is meant by “our universe,” we can now talk about the four possible levels describing the multiverse:
Level 1: Cosmological inflation leads to infinite space containing infinitely many Hubble volumes, each one with precisely the same laws of physics as ours but with a different set of initial conditions. Assuming infinite space and a uniform enough distribution of matter, this implies the existence of another world identical to ours, even including an identical copy of you doing precisely what you are doing right now. In fact, there are infinitely many copies of you.
Level 2: Chaotic expansion occurs during the inflationary epoch, leading to a nearly infinite number of “bubbles” of spacetime in which different local minima of a global energy landscape are realized. Each bubble becomes its own universe, sharing the same fundamental laws of physics that we observe but with different values of the fundamental constants such as the speed of light or the fine-structure constant. This could result in a vastly different reality with a different number of dimensions, different types of matter, and so on.
Level 3: Our current universe is splitting off into an inconceivably large number of parallel branches at every instant, each branch corresponding to a different set of all possible outcomes of all quantum events. These quantum events can in principle range from the most elementary, such as the decay of a neutron into a proton and electron and neutrino, to the most complex, such as the decisions made by self-aware entities. Thus, these parallel universes include all possible alternate histories of this universe and will contain all possible futures. This is known as the “quantum many worlds” interpretation.
Level 4: Different mathematical structures are realized in alternate universes with completely different fundamental laws of physics. There is essentially no limit to the diversity possible in these types of parallel universes.
This may sound incredibly counterintuitive and impossible or merely useless to believe, and I don’t blame you if you feel this way. However, the very same theories that have been extremely successful in describing directly observable physical phenomena are the ones that allow room for the types of parallel universes mentioned above, so they at least warrant consideration. Many physicists find the idea of multiple universes very useful in explaining the so-called anthropic principle, which refers to the seemingly too-good-to-be-true fine tuning of all the fundamental constants in our universe that conspire together to make it a place where life can exist. Believers might be quick to point this out as a sure sign of an intelligent creator, whereas skeptical scientists just point to their infinite universes and explain that it is no big surprise that at least one of them had the perfect combination of conditions to allow for life. As is often the case, faith comes down to a choice between two reasonable alternatives.
Now let me get back on topic. What does all this talk of the multiverse actually contribute to our understanding of God? To be sure, it is not a perfect fit—there are some very sticky issues to be worked out such as communication and transportation between different universes, not to mention the fact that many of the above scenarios begin with the same Big Bang that gave us trouble in the first place—but there is at least a framework in place that would allow God to reasonably exist outside of this universe, thereby escaping the finiteness of his existence and creations that would seem to be implied were he to be a native of our universe. Again, this is a very rough idea at best, but hopefully it gives us another possible way of viewing God and his methods of creation that may be more compatible with modern physical cosmology. The Big Bang, instead of representing an ultimate limit to God, becomes a creative tool in his hands attesting to his knowledge, wisdom, and power. Moreover, these ideas of infinitely many universes leave plenty of room for the infinite progression and eternal increase espoused by Mormon theology. Indeed, the multiverse has a lot to offer in the way of gaining new insights into the nature of the infinite and eternal. Overall, I feel that the multiverse provides the promise of an elegant union between theological and physical cosmologies—a cosmological convergence. And if you don’t agree with me, you probably do in some other universe.
For an accessible review of the theories of the multiverse, and for the source of most of my information in this post, I recommend this paper.