The Unity of the Universe: Nobel-Winning Physicist Steven Weinberg on Simplicity and Complexity, Science and Religion, and the Ultimate Question
By Maria Popova
“If the universe is meaningless, so is the statement that it is so,” philosopher Alan Watts, who popularized ancient Eastern teachings in the West, wrote in his classic 1951 meditation on how we wrest meaning from reality. “The more the universe seems comprehensible, the more it also seems pointless,” the great theoretical physicist, Nobel laureate, and prolific author Steven Weinberg (May 3, 1933–July 23, 2021) observed a generation later in his influential 1977 book The First Three Minutes.
A lazy literalist might miss the point, for this is more Zen koan of science than nihilistic defeatism. Just as acknowledging the illusoriness of free will — a tremendously difficult feat for a thinking, feeling human being — can liberate us rather than take away our freedom, acknowledging the impersonal and disinterested laws of nature governing the universe places on us the power and responsibility to synthesize our own sense of meaning. The “pointlessness” thus becomes the very wellspring of existential significance. (A generation later still, the physicist Sean Carroll would call this “poetic naturalism.”)
Just a few years before the publication of Weinberg’s classic, Hannah Arendt had contemplated this very question in her unforgettable Gifford Lecture on the life of the mind:
Men, if they were ever to lose the appetite for meaning we call thinking and cease to ask unanswerable questions, would lose not only the ability to produce those thought-things that we call works of art but also the capacity to ask all the answerable questions upon which every civilization is founded.
Four decades after his famous proclamation, Weinberg explores the complexity of the question of meaning as it relates to science’s central search for simplicity in We Are All Stardust: Leading Scientists Talk About Their Work, Their Lives, and the Mysteries of Our Existence (public library) — a collection of elegant and erudite interviews by Austrian physicist, essayist, and science journalist Stefan Klein.
In his conversation with Klein, Weinberg considers the reach toward the beauty of simplicity as a core ideal of science:
We want to achieve a simpler understanding of nature. And the path to simplicity is unification. Think of Newton, who discovered that the planets follow the same laws as a stone falling to the ground. So there aren’t separate natural laws for the heavens and earth, as people had thought up to that point — only gravitation, which applies everywhere. That was a great step forward.
[A beautiful theory of nature is] one in which the connections arise inevitably. Everything fits together, and if you try to change even a tiny part, the whole edifice collapses. Such theories exist: Just think of quantum mechanics, which describes the dynamics of atoms and elementary particles.
The most beautiful theory possible, according to this standard, is that which synthesizes the greatest amount of truth about nature into the simplest, most elegant form. And yet Weinberg objects to the fashion of calling such a synthesis a “theory of everything.” In a sentiment that calls to mind Gödel’s insistence on the incompleteness of our logical understanding, he notes:
I don’t like that phrase. It implies that we would understand everything when we’ve reached that goal. But that won’t be the case. Think of phenomena like consciousness or even just turbulence in liquids and gases. We already know the physical and chemical laws underlying them today. And yet we’re far from having understood our consciousness or the weather. That’s why I prefer to call the goal of our search a “final theory.”
In our world we deal with accidents and principles. Accidents can’t be explained. It’s pointless to ask why a comet hit the earth sixty-five million years ago and wiped out the dinosaurs. It’s another thing to attempt to find out something about the rules of heredity among the dinosaurs and all other living things. Those involve underlying principles — to be precise, the principles of biochemistry. And the biochemical laws can be explained in turn by atomic physics. Then comes particle physics, and so on. Ultimately, it boils down to the final theory. That’s where all “why” questions end.
Echoing John Updike’s assertion that “the mystery of being is a permanent mystery, at least given the present state of the human brain,” Weinberg adds:
Another question is whether our brains are powerful enough to even understand these increasingly comprehensive laws. In the end, dogs can’t be trained to solve the Schrödinger equation.
When asked about the seeming parallel between the quest for a unified theory and the central premise of monotheistic religions, Weinberg — himself an atheist of course — inverts the proposition and considers how that very quest, which is at the heart of science, may have also given rise to the religious impulse:
The desire for one God and for a theory of the whole cosmos might have the same cause. Monotheism developed because people found polytheism too complicated. And just as it’s less satisfying to pin storms on Zeus, plagues on Apollo, and the crop yield on Demeter, we physicists would rather have a unified explanation of the world than the complex standard model.
And yet, echoing Milton Glaser’s beautiful assertion that “everything exists at once with its opposite,” Weinberg notes that our human yearning for simplicity coexists with its counterpoint:
When you go to an opera, you’re not looking for simple explanations, but want to experience on the stage the whole diversity and complexity of life… We all bear conflicting needs within us. We want both, simplicity and abundance.
He reflects on his own experience of these polarities:
[Nature fills me with] a sense of beauty, of wonder and mystery. However far we come in the search for a final theory, we’ll never know why the laws of nature are the way they are. A mystery will always remain.
When Klein notes that many people call this sense of mystery and wonder “God,” Weinberg offers his sensitive rationale for why he refuses to use the word “out of respect for history”:
The word “God” has had a fairly clear-cut meaning for centuries in the West: It has meant a being of some sort, a creator concerned with questions of good and evil. I don’t believe in such a God. When Einstein calls a cosmic spirit of beauty and harmony “God,” he is lending the term an entirely new meaning. He seems to me to be doing violence to a well-established word. Ultimately, thinking about nature doesn’t fill me with anything even close to the emotions I would have toward a personal God. The laws of nature are impersonal; they’re not interested in us. How could I have warm feelings for them as I do for another human being or even for my Siamese cat?
We find nothing that gives our lives an objective meaning. There’s nothing in the laws of nature to suggest that we have a particular place in the universe. That doesn’t mean I find my life pointless. We can love each other and try to understand the world. But we have to give our lives that meaning ourselves.
And yet even illusory comfort is comfort, the disappearance of which — however rightful it may be and however rational our reasons for it — nonetheless aggrieves and disquiets us. Weinberg — whose testimony before the Texas Board of Education was instrumental in eradicating from the classroom the religious obstructionism to teaching evolution — considers the sense of loss which accompanies the dissolution of religious untruths:
Human beings regarded themselves as characters in a cosmic drama: We were created, we have sinned, we will be saved — a grand story. Now we realize that we’re more like actors standing around on a stage without direction and we have no choice but to improvise a little drama here, a little comedy there. I experience that as a loss… I feel a certain nostalgia for a bygone age of belief. I find myself attracted to religion. And my aversion to religion stems from the fact that I feel a longing for something I know isn’t true.
But with an eye to the long history of religious wars, from militant Islamism today to the Christian crusades of the Middle Ages, Weinberg makes clear that no such sentimental nostalgia should be subservient to our moral responsibility to truth and its attendant grace of justice:
One of our most important tasks consists in weakening religious certainties.
When asked what could replace the losses of religion, particularly given that religious feelings have inspired much of humanity’s greatest art, Weinberg echoes philosopher Alain de Botton’s case for what secular culture world can borrow from faith and offers:
Great works of art can console us… We can go on enjoying cathedrals and Gregorian chants without believing. And many of the greatest pieces of literature manage without any religious background; just think of all the works of Shakespeare. And in the end we still have humor… We can be amused with ourselves — not with a sneering humor but with a kindhearted one. It’s the sort of humor we feel when we see a child taking its first steps. We laugh at all the child’s arduous efforts, but we do it full of sympathy. And if laughter ever fails us, we can still take a grim satisfaction in the fact that we are able to live without wishful thinking.
Complement this particular portion of the wholly magnificent We Are All Stardust — which includes conversations with icons like primatologist Jane Goodall, cosmologist Martin Rees, evolutionary biologist Richard Dawkins, and geographer Jared Diamond — with Freeman Dyson on the unanswerable questions that give meaning to the universe, Simone de Beauvoir on the spiritual rewards of atheism, and Richard Feynman science and religion.
Published February 1, 2017