To understand how we have reached this precipice, one need only look at developments in theoretical physics over the last few decades. Theoretical physics is the purest expression of science. Exploring the universe with sophisticated and occult mathematics, it searches for the deepest and most explanatory properties of nature. In the name of Isaac Newton, its faithful hunt natural laws as unapologetic Platonists. Their holy grail is a master principle that will explain everything.
According to cosmologist Alan Gurth, “Back in the 1970s and 1980s, the feeling was that we were so smart; we had everything figured out.” It was true, theoretical physicists had come an amazing distance. They had accurately modeled three of the fundamental forces of nature: the strong and weak forces and electromagnetism. No one doubted that the remaining fourth force, gravity, would soon be wedded to quantum physics, with the result that a final theory--a theory of everything--would emerge. In the light of the theory of everything, the universe would no longer be a mystery, but a necessity. Enter the multiverse.
So much has been made of the multiverse on television and in the movies that it seems silly to explain it. Nevertheless, the multiverse is a cosmos fecund with an infinitude of universes, each with an unpredictable and unique set of physical properties. Most would be stillborn wastes of dead rock or awash in the violent spray of hyper radiation. But the tiniest fraction of a fraction of these might contain complex organisms or, rarest of all, intelligent life.
What makes the multiverse idea so necessary to cosmologists is a characteristic of the one universe we do know about--our own. As it turns out, our universe is stunningly, amazingly, fantastically, and completely fine tuned to support life. This characteristic has only grown more miraculous as physicists have better understood how delicate and complex it all is. I imagine that somewhere in the first quarter of the twentieth century this fine tuning was ignored in public and rarely discussed in private. Back then, Einstein’s general relativity was upsetting the comfortable givenness of the solid-state model of the universe. But as our models have become more complex, the evidence of fine tuning has grown to an acuity that no one can ignore.
Such fine tuning forced working physicists into a conundrum. They could roll away the stone and resurrect the argument from design, much to the smug satisfaction of the Intelligent Design community. Indeed, many theists and polytheists argue that the fine-tuning of the universe suggests a transcendent designer. Francis Collins, for example, at the 2011 Christian Scholars’ Conference said, “To get our universe, with all of its potential for complexities or any kind of potential for any kind of life-form, everything has to be precisely defined on this knife edge of improbability. . . . [Y]ou have to see the hands of a creator.” But religion is not an option for science, even though many scientists hold religious beliefs. Science as science cannot embrace unqualified and unrepeatable hypotheses. If it should do this, it instantly becomes another propagandist in a thoroughly political universe, opening the way to the naked power of fascism, the hive mind of socialism, or the cultic and bloody mysteries of theocracy. Here be barbarians.
As it stands, physicists have two options: string theory and the multiverse. String theory has been around for decades. It suggests that the smallest bits of stuff that exist are vibrating, tiny, one-dimensional loops or strings of energy. The differences in their vibrations give rise to the fundamental forces and particles familiar to physics. Many hoped string theory would be able to unify gravity with quantum physics. And if string theorists could pull off this correlation, they would realize the Platonic ideal of a fully explicable cosmos. But, there remains a problem.
At its inception, string theory required a number of extra dimensions: seven at the beginning, with each dimensional fold corresponding to a different universe. Now, however, that number has grown to 10 to the 500th possible universes. It may as well be an infinity, explaining everything and so explaining nothing. Never mind that, as of this writing, string theory has not been supported by a single experimental result, nor has it suggested demonstrable areas of further investigation. It's failure leaves only the multiverse.
Lightman tries his best to assert that a multiverse is at least suggested by modern physics. He points out that eternal inflation suggests it, and cites Alan Guth’s original inflation theory, which was developed by Andrei Linde, Paul Steinhardt, and Alex Vilenkin some twenty years ago. But eternal inflation says that the universe is expanding upon a field of dark energy that has different properties at different points in space--the same energy of which he admits “no one knows what it is.” He goes on to admit that physicists “give a fantastically large range for the theoretically possible amounts of dark energy” (emphasis his). He then abandons eternal inflation and resorts to a pathetic argument from authority, writing, “Some of the world’s leading physicists have devoted their careers to the study of these two theories.” Eventually, however, he has to admit that “neither eternal inflation nor string theory has anywhere near the experimental support of many previous theories in physics, such as special relativity or quantum electrodynamics.” By this he means that the latter two have been independently verified by a number of experiments over the last half of the previous century and have suggested further avenues of research whereas the former are nifty math gymnastics for the initiated. In other words, the multiverse is not the elegant explanation physicists expected. They went looking for a universe of light and form, but wound up with something dark and formless.
Keep in mind that the multiverse idea is no friend to theoretical physics. Lightman admits that “if the multiverse idea is correct, then the historic mission of physics to explain all the properties of our universe in terms of fundamental principles--to explain why the properties of our universe must necessarily be what they are--is futile, a beautiful philosophical dream that simply isn’t true.” If the multiverse idea is true, he continues, then "there is no hope of ever explaining our universe's features in terms of fundamental causes and principles."
Therefore because of our universe’s demonstrable fine tuning for life, theoretical physicists have oh so quietly abandoned empirical science for faith. “Some [physicists] feel relieved,” Lightman says. “Some feel like their lifelong ruminations have been pointless. And some remain deeply concerned, because there is no way they can prove [the multiverse]."
Appealing evangelistically to his scientific peers, Lightman says, "Not only must we accept that basic properties of our universe are accidental and uncalculable. In addition, we must believe in the existence of many other universes. But we have no conceivable way of observing these other universes and cannot prove their existence. . . . We must believe in what we cannot prove.” And so the multiverse, though a perennial boon to science fiction, is as whimsical a figure as the flying spaghetti monster.
What a horrible state of affairs! For without the despotic threat of militant empiricism, the barbarians will most surely come. They will burn libraries in an inferno of anti-intellectualism. They will invoke and totemize the fine tuning of the universe to summon legions of theosophic spiritualisms. Eros will seduce reason, and governments will descend into a night of long knives. Heaven help us! The priesthood is forfeit. The public square lies open. Oh, Alan Lightman, how will they let you live?
Who would have expected it, but the so-called war between religion and science has been but a cordial tete-a-tete all this time. Kept under the watchful eye of white-cloaked science, the churches could relax. All those threats about secularism did but thin the ranks of the Elmer Gantry, allowing ecclesial powers to pay more attention to the faithful. Who needs the hard and divisive labor of doctrine, discipline, and exegetical homiletics when one can employ the far more friendly and quantitative techniques of psychology and business management? Church discipline, private rebuke, and public apologetics are not necessary when only the faithful attend. Science too has benefited. In public, religion has been a noteworthy and engaging sparring partner: good for putting scientists on best-seller lists and magazine covers; good for TED talks, speaker's fees, innumerable conference sessions, and humorous anecdotes (and the benefits flow both ways). In private, scientists haunted by the specter of Oppenheimer have been glad to have an ethical stopgap to keep the whole thing human.