Which Universe Do You Live In?
The success of modern cosmology in understanding the history and structure of the universe has led to a profound crisis in the field, which has significance for the dialogue between science and religion. The topography of the universe discovered by astronomers, physicists, and cosmologists is extraordinary. Our sun, at a distance of 93 million miles, is but a small star in a vast galaxy of some 100 billion stars. This galaxy is but one of a hundred billion other galaxies stretching back some 13 billion years at the speed of light into an infinitely dense and infinitely hot originating mystery. One thing this new cosmology teaches us is that whatever humanity in the past has believed about God is way too small. Most cosmologists, astronomers, and physicists, however, are not interested in doing God-talk; but those of us who do talk-the-talk should certainly be paying attention to the current cosmos conversation.
The situation is such. Imagine that you walk into a classroom and notice that there is a pencil standing on its point on the table. In all those years in elementary school, no matter how hard you tried, you could not make a pencil stand up on its point. But here one day in graduate school, you walked into an empty classroom and there is this pencil standing on its point. So you call in the physics department to help study this strange occurrence.
One possibility is that there is some strange, invisible force that causes this pencil to stand on its point. Gravity aside, physicists are averse to postulating strange, invisible forces, so perhaps this strange pencil is just a weird fluky event, however improbable. Physicists, however, don’t tend to go for weird fluky improbabilities.
Such is the case in contemporary cosmology in what is referred to as the fine-tuning problem. There are a dozen such fine-tuning issues that confound cosmologists. The expansion rate of the universe, the ratio of matter to antimatter, the specific values of the weak and strong nuclear forces, the mass ratios between electrons, protons, and neutrons, the list goes on. If any of these variables were ever so slightly different, then none of the complexity we see around or inside us would be possible. In other words, life and consciousness could not have evolved. Where biologists see random drift and natural selection in the messy story of life, physicists see elegant improbabilities in the ordered and intelligible nature of the cosmos.
Some extend the weird role of the observer in fixing the uncertainty in quantum events to apply to the universe as a whole. Perhaps the universe as a whole is a kind of quantum event, which requires an observer with something like human consciousness to observe it. The distinguished physicist Freeman Dyson reflects “The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense must have known we were coming.” This interpretation is referred to as the anthropic principle. It comes in weak and strong flavors. This interpretation implies a kind of future necessity of our just-so universe, such that present day consciousness determines past actualities. Physicists, however, are also averse to invisible necessities in which future possibilities determine past realities.
At this point, the normal graduate student trying to figure out why the pencil is standing on its point would probably be happy to reconsider the possibility of an invisible force. Our team of physicists and cosmologists are very clever with mathematics which allow them not only to discover realities, but also imagine possibilities which may not be real at all. Such is the case with multiverse theory, the big new fad in contemporary cosmology. The theory goes something like this: we just happen to live in a universe in which the pencil stands on point. There are an infinite number of parallel universes, in which the pencil realizes every other potential state by falling down. While there are sophisticated mathematical models that might predict the existence of multiple universes, as there have long been for multiple dimensions, it is not clear that we could ever have empirical knowledge of these other universes.
Far be I, uninitiated and dimly lit, to weigh in on these complex cosmological considerations. I do not understand the math or the physics. “Since our theories are so far ahead of experimental capabilities, we are forced to use mathematics as our eyes,” notes Brian Greene, a Columbia University string theorist and author of a popular text, The Elegant Universe. Greene continues “That’s why we follow it [mathematics] where it takes us even if we can’t see where we’re going.”
In the past, mathematics has brought us to many stunning new insights about the universe. There may be compelling reasons to suppose our universe really is one piece of a vast multiverse (in which case, the theists will need to infinitely revise the scale of God’s exuberant creativity ). On the other hand, multiverse theory may be the 21st century equivalent of counting how many angels will fit on the head of a pin. In the latter case, all of these sophisticated mathematical contortions are merely a way of avoiding postulating an invisible, intelligent, and conscious force underlying the fine-tuned structures of the universe.