Were some super advanced alien civilization to swoop down to Earth with the definitive explanation of everything in the cosmos, there’d be excitement at first—it would be thrilling to have answers to questions we’ve tussled with through the ages. But in short order, scientists worldwide would be utterly depressed. With no remaining mysteries, the scientific journey would halt.

Whenever I speak about this to middle and high school students, I am struck by how surprising they find it. To the vast majority, science is solely about answers—the material that’s sandwiched between the covers of their textbooks. It’s understandable. For the most part, we teach science as if it were a technical trade: Learn these facts about cells. Memorize these equations describing motion. Balance these reactions that underlie oxidation. And then demonstrate competence by passing an exam. With this lopsided focus on the end points of research, the scientific explorations themselves receive the most minimal attention.

But science is the journey. Science is about immersing ourselves in piercing uncertainty while struggling with the deepest of mysteries. It is the ultimate adventure. Against staggering odds, a species that has walked upright for only a few million years is trying to unravel puzzles that are billions of years in the making. How did the universe begin? How was life initiated? How did consciousness emerge? Einstein captured it best when he wrote, “the years of anxious searching in the dark for a truth that one feels but cannot express.” That’s what science is about.

To be a scientist is to commit to a life of confusion punctuated by rare moments of clarity. When I leave the office at night, the confusion comes with me. Ruminating over these equations, seeking patterns, looking for hidden relationships, trying to make contact with measured data—it’s all uncertainty and possibility engaged in an endless chaotic dance. Every so often the blur resolves, but the respite is short-lived; the next puzzle demands focus. This, really, is the joy of being a scientist. Established truths are comforting, but it is the mysteries that make the soul ache and render a life of exploration worth living.

My own field of research, the quest for a unified theory, is no stranger to uncertainty. A unified theory seeks to meld Einstein’s theory of gravity, a framework that’s relevant when things are large, with quantum mechanics, a body of laws that come into play when things are small. We’ve known for half a century that each of these models works well in its own domain, but each also proclaims that the other is defective. Melding the warring antagonists is essential to gaining insight into other great mysteries—what happened at the big bang, the true fate of matter crushed at the center of a black hole, even the nature of time. I began working on string theory—one of the most promising approaches—25 years ago, as a young graduate student hungry to make a mark on the physics world. It was an exhilarating period leading some to proclaim naively that the insights of string theory would be so sweeping that the end of physics was near. Of course, as more-seasoned observers knew, the end was not near. Even today, while we’ve witnessed stupendous progress and the resolution of problems many thought beyond reach, a final assessment of string theory remains elusive.

To some, this has been a disappointment. But that’s not how I see it. For me, the past decades of anxious searching have illuminated spectacular new landmarks: extra dimensions of space curled into tiny labyrinthine geometries, a cornucopia of universes bubbling up beyond the most distant cosmic horizon, the fabric of space and time being stitched from threads of vibrating strings. These are the partially formed, stunning possibilities that efforts have revealed so far. Are they right? I don’t know. No one does. There’s a chance that the new accelerator in Geneva, the Large Hadron Collider, may give us the first experimental insight.

Regardless of the outcome, the journey has been exhilarating, and through it I feel an emotional connection to the cosmos that I don’t think I could have acquired any other way. My intuition tells me that this particular odyssey will arrive at a promised land, perhaps confirming today’s theoretical insights, perhaps in a future form that will have evolved significantly. But if not, in the unlikely event that the work on which our generation has labored doesn’t make it into textbooks, I can live with that. It’s what happens along the way that radically enriches us. The wrestling with mystery, not the ascension to resolution, defines who we are.

Brian Greene ’84, a physics professor at Columbia University, is the best-selling author of The Elegant Universe and The Fabric of the Cosmos. This piece originally appeared in Wired.