Almost every, if not all, of the generations before us have experienced some pivotal “moment of discovery,” a point when the cumulative exploration and scientific efforts of humankind produced new insights and revelations which the scientists, explorers, and public of the time could distinctly call their own. These are the moments for which those who are around to bear witness are privileged with the opportunity to be “first;” the first generation to learn of the Americas, the first to observe the planets with clarity, the first to experience flight, the first to see man in space. They are those who enjoy the thrill of lingering questions being answered, of unseen horizons being mapped, of worldview and perspective being shaken or changed. There is a profundity in these moments which can hardly be captured by other elements of the human experience; these moments are crucial for not only advancing the forward motion of human progress, but in the impact they have upon our individual understanding of existence.

The profundity of these “moments of discovery” is manifest from the nature of knowledge, which in turn impacts the relationship between the possession of knowledge and the human drive toward understanding. Knowledge is not monolithic; rather, it encompasses different capacities and degrees of understanding. There are, as the axiom goes, the “known knowns, the unknown unknowns, and the known unknowns.” The characteristics which separate these forms of knowledge are distinct and shape our interactions with and reactions toward our expanding ontology. As such, their influence on the nature of “moments of discovery” is significant, indeed key, and it is thus of worth to briefly discuss their characteristics.

The “known knowns” represent that accumulated sum of human knowledge, at hand to us upon our entry into this world, to which we owe our debt of possession to the learned, the explorers, and the scientists who came before us. It is the knowledge which we know we know; the theories and equations which serve as the foundation toward our contemporary understandings. We are generally contented with the “known knowns,” for they provide us the necessary basis of understanding that staves off existential nausea. Equally important, the “known knowns” serve as the framework for further inquiry into the nature of the universe, a safe and familiar staging point from which we probe the depths of the unknown. The process of science builds upon acquired knowledge, even if to disprove it; the “known knowns” are from which all new knowledge is developed and to which the insights of the “moments of discovery” are compared.

There are then the “unknown unknowns,” which provide us the tantalizing impetus for our quest for knowledge; they represent the greater truths or deeper insights that presently lay beyond our comprehension and reach, but whose secrets the work of science seeks to unlock. The “unknown unknowns,” while indeed serving as a key motivational factor in the quest toward knowledge, nonetheless have a minimal role in the formation of our existential anxiety; an individual ignorant of the possibility for knowledge does not experience that apprehension borne from the recognized ignorance of knowledge. That is, we seek to learn what lies within the possible realm of our knowing but worry not about learning what lies beyond the limits of our understanding. Those concerned with and deliberately seeking the “unknown unknowns” are philosophers and theologians, not scientists; dramatic changes in understanding borne from the quest to learn the un-learnable are moments of revelation, not discovery. Of course, the “unknown unknowns” too bleed into “moments of discovery,” for it is the stumbling upon knowledge that we did not know we did not know that makes for revolutionary progress. Indeed, it is often the “unknown unknowns” that are most remembered about “moments of discovery,” even if those moments came in an effort to answer the “known unknowns.” The connection between the “unknown unknowns” and the “known unknowns” in the obtainment of knowledge is therefore both extant and important.

These “known unknowns” are the knowledge which we recognize to be within our capacity for possession but to which we have not yet come. These are those lands beyond the horizon, the worlds yet to be explored, the theories and equations that synthesize together our conceptions of the universe’s function. These are the achievable answers, not yet acquired, to the clear questions regarding our existential position. These are to what the scientists and explorers dedicate their devotion and energy, in order to satisfy the human drive for knowing. Most importantly, the “known unknowns” are, when discovery provides insight from ignorance, what excite the human spirit, what incite shifting in paradigm and theory, what provide impetus for even more ambitious inquiries into the realm of the unknown. The “known unknowns” too are from what progress in human knowledge develops. They are the next bridge to be crossed in the long and winding, perhaps never ending, path toward human enlightenment.

Yet the “known unknowns” are the root of our existential anxiety. A fundamental characteristic of the human experience is the drive away from ignorance; we are compelled at every turn to learn, to experience, to know. We fear ignorance, for only with knowledge do we make sense of the absurdity that is existence. It is true that we fear as well the “unknown unknowns,” as, for example, the ideas of what comes after death or whether there is a grander metaphysical reality than our own have been sources of social and cultural anxiety throughout the entirety of human civilization. Yet these fears are distinct and separate than those borne from the “known unknowns;” they are the fear that we will never know, that such know ledge lies outside the capacity for our understanding. The “unknown unknowns” present a challenge toward our quest for enlightenment in that we cannot understand them, not that we may not understand them. This is the distinction of the “unknown unknowns” from the “known unknowns.” There is a futility in searching for the “unknown unknowns,” and accordingly the anxieties are related to our limitations as humans, not the limitations in our knowledge. The “known unknowns” may be understood, however, but, lying just beyond our present reach, taunt our ignorance. They keep us, who know that something is to be learned, waiting until that “moment of discovery” to finally gain insight. The “known unknowns” are at once frustrating and exciting, inciting within us both anxiety and anticipation.

Such is why “moments of discovery” are so profound; they represent the resolution to our “known unknowns,” the point at which known ignorance is dispelled. For an inquisitive species such as ours, few other experiences resonate so deeply with our fundamental character. When coupled with a discovery of an “unknown unknown,” as these “moments of discovery” so frequently are, humanity’s ontology is greatly expanded. These are discernible moments of tangible and intangible progress, of the advancing of our species – these are thus moments during which we take pride for being human. And indeed, there is something in these moments that resonates with the human desire to belong, to feel a part of something greater than the individual self. There is a compulsion to feel included, be it among a group or within a moment. We take joy in knowing or saying that “I was there.” For the generations that have witnessed these moments of discovery, they rightfully may do so.

Yet there are caveats. Generations subsequent to those which experienced a moment of discovery are of course privy to the acquired knowledge and enjoy the benefit of insight borne from it. Yet a fundamental disconnect exists between the knowledge derived from past discoveries and the generations which were not around to experience its realization. For these generations, such past knowledge is a foundational pillar upon which contemporary understandings exist. It is a given, taken for granted, for such knowledge has always existed during these newer generations’ time. There has been no dispelling of ignorance, or any startling insight, borne from this knowledge, and accordingly it does not have the same profundity or impact upon the newer generations as it did upon the generations around to witness its discovery. Such is why, despite every generation having available to them the breadth of human knowledge past and present, they still seek most readily to learn more, so as to resolve the lingering ignorance still present as a part the human condition. That is, despite every generation having the benefits of insight brought from the “moments of discovery” for which they were not present, every generation still seeks to have its own “moment of discovery.” Every generation desires the ability to say “I was there.”

I have been prompted to conduct this brief discourse on “moments of discovery” because I am soon to experience my own – the encounter with Pluto of the NASA “New Horizons” spacecraft. At the time of this writing, the spacecraft has yet to make its encounter; the specific details of Pluto’s surface and the first up-close images of the distant world have yet to be received. While we know that Pluto is out there, and while we have a rough idea of what its surface may look like, we are still waiting for that “moment of discovery” to reveal to us long-awaited insight. We are soon to replace the “known unknown” that is Pluto’s detailed characteristics with a truer knowledge of them and, hopefully, encounter “unknown unknowns” while doing so. And, as every day passes and as more enticing images are received from New Horizons, I find myself anticipating the excitement that will come when humanity finally lifts the veil of mystery surrounding Pluto.

This soon-to-be “moment of discovery” has, for me, an added profundity. The history of humanity’s exploration of space is hardly half a century old and yet has already radically redefined how we conceptualize our position in the universe. The perspective of humanity has shifted dramatically, from holding a privileged position as the focal point of existence to understanding our true insignificance in the face of the vastness that is time and space. For the two preceding generations, which were around to witness these enormous changes, these “moments of discovery” had no doubt been transformative. Indeed, some would be quick to argue that humanity’s foray into space has resulted in one of the most dramatic evolutions and revolutions in human knowledge. Yet for the greater bulk of the “space age,” I had yet to have been born. Accordingly, those redefinitions of perspective borne through the insights of past space exploration have always been a given for me; I have operated with them as a foundational truth. I have never wondered or been forced to only imagine what Jupiter, Saturn, Uranus, or Neptune look like from close, for the images returned from the Voyager spacecraft have always been available to me. I have never questioned whether man could enter, travel through, and live in space, or what the Moon looks like upon its surface. Humanity has already been there. For most of the incredible discoveries and feats of exploration so far accomplished in humanity’s quest into space, I cannot say that “I was there.” Those moments belong to past generations.

Yet the encounter with Pluto belongs to mine, and the encounter with Pluto will doubtlessly rival, if not surpass, those past “moments of discovery” in its significance. Because of the incredible distances involved in traveling to the far-off world, it is no small wonder that it has taken a half-century of spaceflight to earnestly begin our exploration of it. And it is likely that a moment such as what is soon to come will not occur again in the next half-century. This impending encounter, and the insights and revelations it will bring, is an event of great historical significance, marking the end to the first stages of the exploration of our Solar System. It is one that none of the “space age” generations until mine have experienced, and it is one which the following generations may not witness soon again.

And so, when New Horizons swoops past Pluto, snapping the first ever images clearly showing its surface and thereby closing a chapter on humanity’s exploration of space, I will have witnessed a marked moment of progress for humanity. And with that, I will be proud and privileged to say, as could everyone else alive to witness this historic “moment of discovery,” that “I was there.”