The Incidental Physicists

The universe, it seems, is having something of a moment. In coordination with his newly launched series, “Cosmos,” Neil deGrasse Tyson, hero to astrophysics-nerds and -neophytes alike, has been as ubiquitous as quantum waves. Alfonso Cuarón's film Gravity won over critics and the masses, an unusual triumph. Bill Nye recently endured a highly publicized debate with Creation Museum founder Ken Ham. And then there's Alan Lightman. In The Accidental Universe, the MIT physicist and lauded novelist explores the universe in a scant collection of imaginative essays. Each one examines the world through a different lens; the result is a multifaceted yet elegant picture of the cosmos and our place in it. Lightman's approach is to pose questions, rather than to answer them, which means the debate is left to us, his readers.

In the beginning, there was the multiverse—or at least, that's how Lightman launches this book. The idea, very briefly, is that there could be many (perhaps infinite) universes. But we have no way of confirming or disproving their existence. In this way, he opens a book about knowns and known unknowns with a theory about unknown unknowns—or faith. How does this essay set the stage for the rest of the book?

Geoffrey Young: As the one of us who rejects the multiverse theory, I have to acknowledge that Lightman's discussion of it sets the perfect tone for the rest of the book. Grappling with the “fine-tuning conundrum,” which is the question of how our universe is so perfectly calibrated to support life, the multiverse theory swoops in as a deus ex machina for intrepid theoretical thinkers: the narrative has a problem, and we need to bring something in, even something that doesn't abide by the rules we've established, to tie up loose ends. But the idea, explained in the essay “The Accidental Universe” (and it must be no small thing that the same essay lends its name to the book), allows the answer to be that our life-supporting universe is a probability, given zillions (or infinite) possibilities. Which is to say, the existence of uncountable universes makes life statistically probable, thereby solving the fine-tuning conundrum. The multiverse obviates the “why.” Very convenient.

Lightman grounds the headiness of his essay by likening us, and our cosmic theories, to fish wondering why their world is watery. Their aim is to prove the necessity of their world's condition, seeing as they are in it. But the most wizened of their schools will offer the difficult suggestion that there may be other worlds unlike their own, “some of them completely dry, some wet, and everything in between." The example is useful for simplifying the nature of Lightman's investigation, and even more useful for revealing how it cannot be simplified. Not only do we humans know the nature of the worlds surrounding the fishes' watery one, a curious fish could also swim up to the surface, take a breath, and look for herself. By contrast, we don't know any damn thing about these proposed other universes. “The multiverse idea offers an explanation to the fine-tuning conundrum that does not require the presence of a Designer," Lightman tells us. I wonder to what degree is the multiverse idea borne out of rejection of Intelligent Design? The presence of a Designer is odious to many physicists, so they have contrived a reality that doesn't need one. And boy, “contrived" is the word. At the very least, people can claim to have experienced God, subjective as those accounts may be. Has anyone experienced the multiverse? Lightman himself admits, “The other universes themselves will almost certainly remain a conjecture."

So this is the book we're reading. The latest theories of our foremost physicists are matters of faith. Onward!

Katie Rolnick: I don't disagree with your characterization of the multiverse, but my feelings toward it are much fonder. I take comfort in thinking there are things that at the moment seem unknowable—but perhaps, given enough time and the desire, we could grasp them. Of course, accepting the multiverse theory could lead us to throw in the towel; if our universe is simply one roll of the dice among infinite rolls, a statistical inevitability, why bother to investigate it? But the theory could also induce the opposite reaction and motivate further inquiry. In a later essay, Lightman suggests scientists need mystery. He conveys what physicist Maria Spiropulu told the New York Times when it looked like the elusive Higgs-Boson particle may have been discovered: “I personally do not want [the new particle] to be the Standard Model anything—I don't want it to be simple or symmetric or as predicted. I want us all to have been dealt a complex hand that will send me and all of us in a good loop for a long time." The multiverse could be that kind of loop, for although we can't conceive of those other universes now, what if we could? This is, I think, the crux of the “wizened fish" analogy. These other universes could be the dry, semi-dry worlds to the fish. True, we can't yet conceive of their conditions. But if we are wise, we allow that they might exist—and then perhaps we find ways to learn something of them. (Then we become amphibians, I suppose.)

Framed this way, accepting the possibility of the multiverse seems less to tie up loose ends then to unravel a new spool. For example, in an essay called “The Symmetrical Universe," Lightman explores the evolutionary development of biological symmetries. (The reason? Efficiency!) But he also points out certain underlying symmetries, such as physicist Steven Weinberg and Abdus Salam's electroweak theory. Unlike the equidistance of, say, a starfish's arms, Lightman explains that “as far as we know, the symmetries in the electroweak theory…did not evolve from ongoing experiments with different designs. Rather, they were apparently built in at the origins of the universe, by whatever processes and principles determined the fundamental laws of physics."

As someone whose physics education culminated with a trip to Six Flags, this may be crazy talk…but what if the multiverse is that ongoing experiment? Could it present an opportunity to explore evolution on a much grander scale, placing our universe in a genealogical tree of universes? Who knows? But certainly, the multiverse offers the chance to discover things we didn't fathom existed (much less could be understood). Yes, it demands a level of faith—as does any hypothesis. You must pursue it with fervor, believing it could be true. But you also accept when evidence shows your faith to be false.

One of Lightman's greatest gifts is his ability to translate ideas that would otherwise be inscrutable for a lay audience. He finds simple yet rich analogies that illustrate the upshot of very complex scientific theories. And yet, despite the triumph of language to convey these ideas, Lightman returns again and again to the idea that there are linguistic limits. Our words are inspired and shaped by our perceptions of the world and as science moves farther from the experiential into the realms of the infinitesimally small and the infinitely gargantuan—neither of which we can perceive directly—language fails us. And he shows that these limitations overlap with another paradox: our understanding of the universe is circumscribed by our presence in it. The observer is part of the observed system. He threads this idea through the book in various ways: We prefer symmetry because nature prefers symmetry and we are of nature. We struggle to understand Einstein's theory of relativity because our experience of time is inherently relative. Taken to the logical extreme, if we are part of a system that can be explained by science, is there anything essential within us that cannot be explained by the same methods?

GY: What continues to be troublesome, and a rhetorical sticking point in debates, is the assumption that the scientific method of explaining something is the method of explaining something. Lightman's discussion of language failing to describe emergent understanding is fascinating because it suggests the place where theoretical science bumps up against religion. One of my heroes of biblical study, Karen Armstrong, says in her book, A History of God, “All the major religions would agree that it is impossible to describe this [experience of human transcendence] in normal conceptual language. Monotheists have called this transcendence 'God,' but they have hedged this around with important provisos. Jews, for example, are forbidden to pronounce the sacred Name of God, and Muslims must not depict the divine in visual imagery. The discipline is a reminder that the reality we call 'God' exceeds all human expression.”

Now Lightman tells us, quoting Niels Bohr, that scientific understanding is beginning to exceed human expression. Does this prove anything? Does it tilt the argument against science or in favor of it? Would it suggest that while we fight each other over which system is more limited, religion or science, the inconvenient truth is that we are limited? So it stands to reason that our systems will be, too?

My answer to the question, then, is yes, there is something essential within us that can't be explained by science—but the reason I say that is only that science hasn't explained it. I don't know that it will. As a human being who cannot predict the future, deciding whether or not science can explain our “humanness” (emotions, love, transcendence) is a matter of faith. In his discussion of atheism in The New Yorker, “Bigger Than Phil: When Did Faith Start to Fade?” Adam Gopnik paraphrases historian Peter Watson by suggesting today's brand of “believer” feels simply that "a material account of existence is inadequate to our numinous-seeming experience.” I can't help but align myself with that viewpoint. While I might accept that a powerful-enough computer could conceivably unlock a formula for an individual's behavior, we still wouldn't be able to grasp it. And what fills a gap in comprehension? Gopnik again: “Expert defenders [of faith] are more and more inclined to seize on the tiniest of scientific gaps or to move ever upward to ideas of God so remote from existence as to become pure hot air… a God whose province is whatever science can't yet explain.”

Okay, so the “Man in the sky” may have had his day. But Lightman's anecdote about the mysterious “connectedness” he once felt in a shared glance with a fledgling osprey, “one of the most profound moments of [his] life,” is acknowledgement that humankind's common experience of the numinous is as strong as ever. When the all-knowing computer knows me better than I know myself, I will likely refer to it thenceforth as Computer, and it will be the focal point of my religiosity.

KR: Yes, the language of faith and science both run up against limitations. But the key difference seems to be our relationship to those limits. Religion, by necessity, accepts and celebrates them out of reverence for that which absolutely cannot be known, whereas science can confront them as a challenge to be explored. This is not to suggest that our intellect is supremely powerful, but rather to point out that the boundaries on our ability to describe (and thus comprehend) are finite in religion and fluid in science.

The reason people turn to science as the method is because it compels us to test, to understand, to know. While it is appealingly humble to accept our humanness as unknowable, is it not humbler still to accept our equality with the rest of our world? If we seek to understand that world through science, why should our understanding of ourselves be any different? To a point, we accept this. We understand our bodies through biology and chemistry. But it's the mind that bothers us—which I would argue is really a way of saying our autonomy. This is implicit in Lightman's discussion of the mechanists (me) and the vitalists (you). He writes: “Taking the laws of nature and the physicality of the world to their natural conclusion, shouldn't our thoughts and behavior be completely predictable given a large enough computer?” We balk at such a proposition, hating to think that our lives can be reduced to mere science. And yet, religious believers happily ascribe existence (and fate) to an unknowable God.

You concede that at some point a super-computer could recreate something as seemingly fickle as our emotions, as mysterious as transcendence. But you also reject ambiguity, instead choosing to assert that our essential humanity cannot be known, even if it could be replicated. And that is itself a proclamation of faith. In that same Gopnik article on atheism, he says there are certain aspects of life beyond the purview of science. However, he contends, “The plausible opposite of 'permanent scientific explanation' is 'singular poetic description,' not 'miraculous magical intercession.'" This corrective satisfies both our desire to convey the ineffable human experience while identifying the specious nature of a reliance on faith.

Though our powers of observation may be limited by our participation in the system, we have found ways to escape these restrictions. We often rely on instruments and technology to do the observing for us. Which makes the final essay, “The Disembodied Universe” so perplexing. How did you respond to Lightman's skepticism of contemporary consumer technology?

GY: Sometimes I think Lightman must hurt his own feelings with the imaginative distances his considerable intellect takes him. He is very much in love with the experience of being human, with all its glories and all its challenges. But when physicists really get going on the nature of all things, the grandeur of humanity is inevitably diminished.

The final essay, “The Disembodied Universe,” completes our journey from the grand and gargantuan, an infinity of universes of inconceivable scope, to the specific evolving capacities for perception of each individual human being. He leaves us with thoughts on how we experience the world, on what our subjective realities are. I don't find him skeptical at all. I find him nostalgic. I find him, as might be said of physicists in general, sentimental. Even physicists are humans! And all humans will get older, look at the changing human world, shake their heads and mutter, “Kids today.”

Taken as a whole, the book is discussion, not dogma. It is a laying out of the debate as it currently stands. Lightman isn't making an argument, he is merely shining the light of his fascinatingly dichotomous expertise on humankind's fascinatingly dichotomous common experience. It is in perfect keeping with his tone throughout to conclude with an exhortation to today's device-driven youth to remember the beauty of the world as it appears directly to their senses.

KR: Certainly he's nostalgic and sentimental—and yes, that is in step with his persona throughout the book. But there's also a hardy streak of skepticism in this essay. Lightman describes taking long walks in a nature preserve near his home. While he absorbs the world through his senses, he's disheartened to see others talking on cell phones as they walk. “They are attempting to be several places at once, like quantum waves,” he writes. “But I would argue that they are nowhere." And a paragraph later, “The most unfortunate aspect of this new behavior is that more and more people, and especially young people, are taking such mediated experiences as 'natural,' as the norm.” The first statement hints at his skepticism and the second hits it home with “unfortunate." Of course, as a scientist, Lightman should be skeptical. But if he keeps true to the scientific pursuit, that doubt should ignite inquiry. He poses a fascinating question of those strolling and talking on their phones: “Where are their minds and bodies?” But instead of finding ways to explore and test that question, he lets his feelings (nostalgia, sentiment) dictate the answer. What's frustrating about this chapter is not his skepticism but his response to it. He falls prey to a common prejudice: people often think of science as rigid and sterile. But Lightman himself has shown us that it surges with creativity and lyricism.

In the end, Lightman guides us away from the why of our existence to the how and what. But he cannot avoid the why. It's what we all want to know. And obviously, the question plagues Lightman. But as an avowed humanist, he struggles with faith. While reading, when did you find the why tugging at you most? And how successful is Lightman at either moving you toward other questions or offering a resolution?

GY: Does he struggle with faith? He strikes me as very comfortable with it: “For me, there is room for both a spiritual universe and a physical universe, just as there is room for both religion and science.” I guess that comfort is easy for a scholar in an armchair, someone whose vocation is posing problems and approaching solutions to them with maximum variety. Certainly, he would argue that the scientific method of inquiry cannot be applied to an investigation of the existence of god (which the word "faith” indicates, anyway), but his point is that there is not a choice to be made. Did you watch the debate between Bill Nye and Creation Museum CEO Ken Ham? Author Sean McElwee in Salon.com says in his piece on the debate, “I propose, with [evolutionary biologist] Stephen Jay Gould and the Catholic Church that we recognize that religion and science are two entirely different realms." Karen Armstrong discusses it brilliantly in the intro to her book about fundamentalism, The Battle for God. Regarding the concepts of mythos and logos in the premodern world she writes: "…mythos and logos were regarded as indispensable. Each would be impoverished without the other. Yet the two were essentially distinct, and it was held to be dangerous to confuse mythical and rational discourse. They had separate jobs to do. Myth was not reasonable; its narratives were not supposed to be demonstrated empirically. It provided the context of meaning that made our practical activities worthwhile… Logos could not answer questions about the ultimate value of human life.”

Is the answer merely accepting that there is no nexus between the physical and the spiritual? A great many people can't seem to accept the gulf. One has to be right, the other wrong. The fact is they are both wrong. Neither answers everything. And just as Christianity teaches its followers that they are imperfect and their mission in life can only be to find a closer communion with God, so science must admit to the limits of its understanding.

KR: I did watch the debate and was both frustrated and underwhelmed. Sean McElwee's piece pinpoints much of that frustration, but I have a tough time with his resolution. It's all fine and well to erect a firewall between religion and science—in theory. But that is impossible in practice, and in fact your parenthetical suggests why. You rightly assert that Lightman would argue, “the scientific method of inquiry cannot be applied to an investigation of the existence of god (which the word “faith" indicates, anyway)…” But faith's entanglement with god is precisely the problem. Because although they are not the same thing, is it reasonable to think we could ever reframe one without the other? Lightman attempts to extricate faith from the grips of religion, because with god in the picture, there inevitably comes a point where science and faith will conflict. So while Lightman doesn't struggle with faith, he struggles to defend its place in his scientific practice.

There is another, even more troubling aspect of the division of faith and science. McElwee quotes Martin Luther King, Jr. as saying, “Science keeps religion from sinking into the valley of crippling irrationalism and paralyzing obscurantism. Religion prevents science from falling into the marsh of obsolete materialism and moral nihilism.” While it feels like sacrilege to question a thinker as esteemed and compassionate as King, I'm going to venture out on a limb: I'm happy to leave people with their religious traditions, but as long as we attribute rectitude to this realm, we run the risk of someone like Ken Ham dictating morality by taking the written word at its word. Certainly, as science progresses and we come to better know ourselves through it, we will confront new and complex ethical questions. But the answers are not the sole province of the faithful. Rather, discovering moral resolutions demands the same rigorous thinking and careful analysis we apply to any vital endeavor—including science.