“You put that line,” the great director Robert Altman enthused about his love of fishing, “and you don’t know what’s on the other end. Your imagination is under there.”

In The Simple Beauty of the Unexpected: A Natural Philosopher’s Quest for Trout and the Meaning of Everything (public library), Dartmouth astrophysicist Marcelo Gleiser argues that angling into the unknown to plumb its imaginative possibilities is also what science does. At the age of eleven, well before he became a theoretical physicist and came to study questions once considered outside the realm of science — question about the origin and nature of the universe — Gleiser grew enchanted with fishing as “a portal into a spiritual dimension of being, a way to transcend the clutch of time.”

Like gardening, an activity of larger metaphorical dimensions, fishing, Gleiser found, offers an apt metaphor for the essence of the scientific spirit. He writes:

Fishing teaches us to be patient, tolerant, humble — key qualities needed in research. How often do fishermen go to the water with their rods, dreaming of the day’s catch, only to come home empty-handed? Likewise, how often do scientists passionately explore an idea for days, weeks, months, years even, only to be forced to accept that it leads nowhere? Notwithstanding the frequent failures, and just as in fishing, they keep coming back, even if the odds for success are pretty low. The thrill is in beating the odds, occasionally landing a big fish or an idea that reveals something new about the world.

In fishing and in science we flirt with the elusive. We stare at the water, and sometimes we see a fish stir underneath the surface or even jump, betraying its presence. But the watery world is not our own, and we can only conjecture about what really goes on down there, polarized lenses and all. The line and the hook are our probes into this other realm, which we perceive only very imperfectly.

Echoing pioneering biochemist Erwin Chargaff’s beautiful meditation on the poetics of curiosity and our natural blinders to reality, Gleiser adds:

We see very little of what really goes on around us. Science is our probe into invisible realms, be it the world of the very small, of bacteria, of atoms, of elementary particles, or the world of the very large, of stars, galaxies, and even the Universe as a whole. We see these through our tools of exploration– our reality amplifiers — the telescopes, the microscopes, and the many other instruments of detection, the rod and line of the natural scientist. If we are persistent, once in a while we see Nature stir, even jump, revealing the simple beauty of the unexpected.

In one particularly poetic passage, Gleiser recounts his own encounter with that simple, scintillating beauty during a walk in the wilderness after a lecture in England. He writes:

A public footpath meanders along the river. I approached it through a narrow alleyway just beneath the castle. A huge sycamore bowed ceremoniously over the dark green water. I paused to appreciate the view, infused with a deep sense of peace. A cloud of mayflies wobbled just above the current, joyfully celebrating their twenty-four-hour existence. Suddenly, out of the depths, a salmon leaped some three feet into the air, swallowed one of them, and dived back with a noisy splash. The fish must have been at least six pounds, maybe more. I just stood there, motionless, mouth agape.

[…]

Was it an omen? Of course it was! Only a fool, blind, sad rationalist would wave away something like this, dismissing it as a mere coincidence. When an event is meaningful it becomes more than a mere coincidence. I’m not saying that some supreme supernatural power or some river spirit planted the message just for me. That would be nonsensical and hopelessly self-centered. The salmon jumped, and I happened to be right there to see it. Why take away from the simple beauty of what had just happened, attributing it to an invisible and elusive conductor? What should be worshipped here is not some invisible, unknowable magic hand but the serendipity of the event, the emotional impact it had on me. The salmon’s timeline and my own overlapped for a few brief seconds of pure and absolute bliss. There is no need to bring anyone or anything else into the picture.

The gap between our expectations and this marvel of the unexpected, of course, is what gave rise to ancient mythologies and superstitions. But learning to inhabit that gap is at the heart of what Alan Lightman has so memorably called “the full engagement with this strange and shimmering world.” It is part of, and perhaps the whole of, our search for meaning. Gleiser writes:

The meaning of life is to find meaning in life.

With a lucid eye to how our ancestors went about finding meaning, Gleiser notes:

The whole notion of a supernatural influence doesn’t really make sense. After all, an “influence” denotes a physical occurrence or an event. And an occurrence is something that happens in the physical world through some kind of energy exchange. Any kind of energy exchange or force is very natural and requires a very natural cause. In other words, as soon as the supernatural becomes physical enough to be noticed or detected in some way, it can’t remain supernatural anymore. A “supernatural influence” is an oxymoron.

[…]

The unexplainable — to be distinguished from the not-yet-explained, which is the province of science — is unavoidable. And should be welcomed. We are surrounded by mystery, by what we don’t know and, more dramatically, by what we can’t know.

Echoing Hannah Arendt’s insistence on the importance of unanswerable questions and building upon his own earlier work about the mystery of nature and the nature of mystery, Gleiser considers the necessity of embracing doubt as an integral part of our pursuit of knowledge:

If our accumulated knowledge of the world makes up an island, the island grows as we learn more. (It may also occasionally shrink, as we discard an erroneous theory or explanation.) As with every island, this one is also surrounded by an ocean, in this case the ocean of the unknown. However — and here is the twist — as the island grows, so do the shores of our ignorance, the boundary between the known and the unknown. In other words, new knowledge generates new unknowns. Unless we stop asking questions about Nature, there is no possible end to our search.

In a sentiment that calls to mind Bertrand Russell’s timeless clarion call for the discipline of doubt, Gleiser adds:

We must conclude that this ever-growing body of knowledge called science cannot explain all there is for the simple reason that we won’t ever know all there is to explain. How could we possibly know all the questions to ask? To presume that we can know all there is to know only shows how supremely arrogant some people can be. It also flies against all that we have learned about how science generates knowledge.

[…]

But … understand the limitations of science is not the same as labeling it as weak or exposing it to the criticism of antiscience groups, such as Bible literalists. It is, in fact, liberating to those who consider it, as it frees science from the burden of being godlike, all-knowing and all-powerful. It protects its integrity in a time when so many claims from scientists get inflated beyond their validity, either by those making them (they should know better) or by the media… Furthermore … why should we want to know everything? Imagine how sad it would be if, one day, we arrived at the end of knowledge. With no more questions to ask, our creativity would be stifled, our fire within extinguished. That, to me, would be incomparably worse than embracing doubt as the unavoidable partner of a curious mind. Science remains our most effective tool to explore the world in its myriad manifestations. However, we shouldn’t lose sight of the fact that it is a human invention and that, as such, it does have limitations. Every system of knowledge is fallible.

And yet limited as it may be, science is still our finest searchlight for knowledge amid the darkness of the unknown — knowledge which we transmute into wisdom, out of which we then wrest meaning — or, rather, meanings. Looking back on his own path to becoming a scientist with the modern makings of a natural philosopher, Gleiser reflects:

This manifold devotion, this search for different ways to connect with something bigger than I am, can only be called love. Einstein called it the experience of the mysterious — “the cosmic religious feeling” — to him the most significant we could have, the awe we feel as we contemplate Creation. (By “Creation” with a capital C I mean the totality of Nature.) In my view, it is the purest form of spirituality, the manifold experience of our profound connection with the cosmos. From Nature we came, in Nature we are, to Nature we go.

Complement Gleiser’s altogether excellent The Simple Beauty of the Unexpected with Alan Lightman on the transcendence of discovery and 19-year-old Sylvia Plath on finding nonreligious divinity in nature.