Until the End of Time Read online

  These are all ongoing stories, developed by thinkers hailing from a great range of distinct disciplines. Understandably so. A saga that ranges from quarks to consciousness is a hefty chronicle. Still, the different stories are interlaced. Don Quixote speaks to humankind’s yearning for the heroic, told through the fragile Alonso Quijano, a character created in the imagination of Miguel de Cervantes, a living, breathing, thinking, sensing, feeling collection of bone, tissue, and cells that, during his lifetime, supported organic processes of energy transformation and waste excretion, which themselves relied on atomic and molecular movements honed by billions of years of evolution on a planet forged from the detritus of supernova explosions scattered throughout a realm of space emerging from the big bang. Yet to read Don Quixote’s travails is to gain an understanding of human nature that would remain opaque if embedded in a description of the movements of the knight-errant’s molecules and atoms or conveyed through an elaboration of the neuronal processes crackling in Cervantes’s mind while writing the novel. Connected though they surely are, different stories, told with different languages and focused on different levels of reality, provide vastly different insights.

  Perhaps one day we will be able to transit seamlessly between these stories, connecting all products of the human mind, real and fictive, scientific and imaginative. Perhaps we will one day invoke a unified theory of particulate ingredients to explain the overwhelming vision of a Rodin and the myriad responses The Burghers of Calais elicits from those who experience it. Maybe we will fully grasp how the seemingly mundane, a glint of light reflecting from a spinning dinner plate, can churn through the powerful mind of a Richard Feynman and compel him to rewrite the fundamental laws of physics. More ambitious still, perhaps one day we will understand the workings of mind and matter so completely that all will be laid bare, from black holes to Beethoven, from quantum weirdness to Walt Whitman. But even without having anything remotely near that capacity, there is much to be gained by immersion in these stories—scientific, creative, imaginative—appreciating when and how they emerged from earlier ones playing out on the cosmic timeline and tracing the developments, both controversial and conclusive, that elevated each to their place of explanatory prominence.4

  Clear across the collection of stories, we will find two forces sharing the role of leading character. In chapter 2 we will meet the first: entropy. Although familiar to many through its association with disorder and the often-quoted declaration that disorder is always on the rise, entropy has subtle qualities that allow physical systems to develop in a rich variety of ways, sometimes even appearing to swim against the entropic stream. We will see important examples of this in chapter 3, as particles in the aftermath of the big bang seemingly flout the drive to disorder as they evolve into organized structures like stars, galaxies, and planets—and ultimately, into configurations of matter that surge with the current of life. Asking how that current switched on takes us to the second of our pervasive influences: evolution.

  Although it is the prime mover behind the gradual transformations experienced by living systems, evolution by natural selection kicks in well before the first forms of life start competing. In chapter 4, we will encounter molecules battling molecules, struggles for survival waged in an arena of inanimate matter. Round upon round of molecular Darwinism, as such chemical combat is called, is what likely produced a series of ever more robust configurations ultimately yielding the first molecular collections we would recognize as life. The details are the stuff of cutting-edge research, but with the last couple of decades of stupendous progress, the consensus is that we are heading down the right track. Indeed, it may be that the dual forces of entropy and evolution are well-matched partners in the trek toward the emergence of life. While that might sound like an odd coupling—entropy’s public rap veers close to chaos, seemingly the antithesis of evolution or of life—recent mathematical analyses of entropy suggest that life, or at least lifelike qualities, might well be the expected product of a long-lived source of energy, like the sun, relentlessly raining down heat and light on molecular ingredients that are competing for the limited resources available on a planet like earth.

  Tentative though some of these ideas currently are, what’s certain is that a billion or so years after the earth formed it was teeming with life developing under evolutionary pressure, and so the next phase of developments is standard Darwinian fare. Chance events, like being hit by a cosmic ray or suffering a molecular mishap during the replication of DNA, result in random mutations, some with minimal impact on the organism’s health or welfare but others making it more or less fit in the competition for survival. Those mutations that enhance fitness are more likely to be passed on to descendants because the very meaning of “more fit” is that the trait’s carrier is more likely to survive to reproductive maturity and produce fit offspring. From generation to generation, qualities that enhanced fitness thus spread widely.

  Billions of years later, as this long process continued to unfold, a particular suite of mutations provided some forms of life with an enhanced capacity for cognition. Some life not only became aware, but became aware of being aware. That is, some life acquired conscious self-awareness. Such self-reflective beings have naturally wondered what consciousness is and how it arose: How can a swirl of mindless matter think and feel? Various researchers, as we will discuss in chapter 5, anticipate a mechanistic explanation. They argue that we need to understand the brain—its components, its functions, its connections—with far greater fidelity than we now do, but once we have that knowledge, an explanation of consciousness will follow. Others anticipate that we are up against a far greater challenge, arguing that consciousness is the most difficult conundrum we have ever encountered, one that will require radically new perspectives regarding not just mind but also the very nature of reality.

  Opinions converge when assessing the impact our cognitive sophistication has had on our behavioral repertoire. Across tens of thousands of generations during the Pleistocene, our forebears joined together in groups that subsisted through hunting and gathering. In time, an emerging mental dexterity provided them with refined capacities to plan and organize and communicate and teach and evaluate and judge and problem-solve. Leveraging these enhanced abilities of the individual, groups exerted increasingly influential communal forces. Which takes us to the next collection of explanatory episodes, those focused on developments that made us us. In chapter 6 we examine our acquisition of language and subsequent obsession with the telling of stories; chapter 7 probes a particular genre of stories, those that foreshadow and transition into religious traditions; and in chapter 8 we explore the long-standing and widespread pursuit of creative expression.

  In seeking the origin of these developments, both common and sacred, researchers have invoked a wide range of explanations. For us, an essential guiding light will continue to be Darwinian evolution, applied now to human behavior. The brain, after all, is but another biological structure evolving via selection pressures, and it is the brain that informs what we do and how we respond. Over the past few decades, cognitive scientists and evolutionary psychologists have developed this perspective, establishing that much as our biology has been shaped by the forces of Darwinian selection, so too has our behavior. And thus in our trek across human culture we will often ask whether this or that behavior may have enhanced the prospects for survival and reproduction among those who long ago practiced it, promoting its wide propagation throughout generations of descendants. However, unlike the opposable thumb or upright gait—inherited physiological features tightly linked to specific adaptive behaviors—many of the brain’s inherited characteristics mold predilections rather than definitive actions. We are influenced by these predispositions but human activity emerges from a comingling of behavioral tendencies with our complex, deliberative, self-reflective minds.

  And so a second guiding light, distinct but no less important, will be trained o
n the inner life that comes hand in hand with our refined cognitive capacities. Following a trail marked by many thinkers, we will come to a revealing vista: with human cognition we surely harnessed a powerful force, one that in time elevated us to the dominant species worldwide. But the mental faculties that allow us to shape and mold and innovate are the very ones that dispel the myopia that would otherwise keep us narrowly focused on the present. The ability to manipulate the environment thoughtfully provides the capacity to shift our vantage point, to hover above the timeline and contemplate what was and imagine what will be. However much we’d prefer it otherwise, to achieve “I think, therefore I am” is to run headlong into the rejoinder “I am, therefore I will die.”

  Mildly put, the realization is disconcerting. Yet most of us can take it. And our survival as a species attests to our brethren having been able to take it too. But how do we do it?5 According to one line of thought, we tell and retell stories in which our place in a vast universe migrates to center stage, and the possibility of our being permanently erased is challenged or is ignored—or, simply put, is just not in the cards. We craft works in painting, sculpture, movement, and music in which we wrest control of creation and invest ourselves with the power to triumph over all things finite. We envision heroes, from Hercules to Sir Gawain to Hermione, who stare down death with a steely resolve and demonstrate, albeit fancifully, that we can conquer. We develop science, providing insights into the workings of reality that we transform into powers earlier generations would have reserved for gods. In short, we can have our cognitive cake—the nimbleness of thought that, among much else, reveals our existential predicament—and enjoy eating it too. Through our creative capacities we have developed formidable defenses against what would otherwise have been debilitating disquiet.

  All the same, because motives don’t fossilize, tracing the inspiration for human behavior can be a knotty undertaking. Perhaps our creative forays, from the stags at Lascaux to the equations of general relativity, emerge from the brain’s naturally selected but overly active ability to detect and coherently organize patterns. Perhaps these and related pursuits are exquisite but adaptively superfluous by-products of a sufficiently large brain released from full-time focus on securing shelter and sustenance. As we will discuss, theories abound but unassailable conclusions are elusive. What lies beyond question is that we imagine and we create and we experience works, from the Pyramids to the Ninth Symphony to quantum mechanics, that are monuments to human ingenuity whose durability, if not whose content, point toward permanence.

  And with that, having considered cosmic origins, explored the formation of atoms, stars, and planets, and swept across the emergence of life, consciousness, and culture, we will cast our sights toward the very realm that for millennia, literally and symbolically, has both stimulated and quelled our cosmic anxiety. We will look, that is, from here to eternity.

  Information, Consciousness, and Eternity

  Eternity will be a long time coming. A lot will happen along the way. Breathless futurists and Hollywood sci-fi spectaculars envision what life and civilization will be like over spans that while significant by human standards pale in comparison to cosmic timescales. It is an entertaining pastime to extrapolate from a short stretch of exponential technological innovation to future developments, but such predictions are likely to differ profoundly from how things will actually unfold. And that’s over relatively familiar durations of decades, centuries, and millennia. Over cosmic timescales, predicting these sorts of details is a fool’s errand. Thankfully, for most of what we will explore here, we will find ourselves on more solid ground. My intent is for us to paint the future of the universe with rich colors but only with the broadest of strokes. And with that level of detail, we can portray the possibilities with a reasonable degree of confidence.

  An essential recognition is that there is little emotional equanimity to be gained from leaving a trace on a future bereft of anyone there to notice. The future we tend to envision, even if only implicitly, is one that’s populated by the kinds of things we care about. Evolution will surely drive life and mind to take on a wealth of forms supported by a range of platforms—biological, computational, hybrid, and who knows what else. But regardless of the unpredictable details of physical composition or environmental backdrop, most of us imagine that in the vastly distant future, life of some stripe, and intelligent life more particularly, will exist and it will think.

  And this raises a question that will ride along with us throughout the journey: Can conscious thought persist indefinitely? Or might the thinking mind, like the Tasmanian tiger or the ivory-billed woodpecker, be something sublime that rises up for a period but then goes extinct? I’m not focused on any individual consciousness, so the question has nothing to do with wished-for technologies—cryogenic, digital, whatever—capable of preserving a given mind. Instead, I am asking whether the phenomenon of thought, supported by a human brain or an intelligent computer or entangled particles floating in the void or any other physical process that proves relevant, can persist arbitrarily far into the future.

  Why wouldn’t it? Well, think about the human incarnation of thought. It arose in conjunction with a fortuitous set of environmental conditions explaining why, for example, our thinking takes place here and not on Mercury or on Halley’s comet. We think here because the conditions here are hospitable to life and thought, which is why deleterious changes to earth’s climate are so distressing. What’s not at all obvious is that there is a cosmic version of such consequential but parochial concerns. By thinking of thought as a physical process (an assumption we will examine), it is not surprising that thought can take place only when certain stringent environmental conditions are met, whether on earth in the here and now or somewhere else in the there and then. And so as we consider the broad-brush evolution of the universe, we will determine whether the evolving environmental conditions across space and time can support intelligent life indefinitely.

  The assessment will be guided by insights from research in particle physics, astrophysics, and cosmology that allow us to predict how the universe will unfold over epochs that dwarf the timeline back to the bang. There are significant uncertainties, of course, and like most scientists I live for the possibility that nature will slap down our hubris and reveal surprises we can’t yet fathom. But focusing on what we’ve measured, on what we’ve observed, and on what we’ve calculated, what we’ll find, as laid out in chapters 9 and 10, is not heartening. Planets and stars and solar systems and galaxies and even black holes are transitory. The end of each is driven by its own distinctive combination of physical processes, spanning quantum mechanics through general relativity, ultimately yielding a mist of particles drifting through a cold and quiet cosmos.

  How will conscious thought fare in a universe experiencing such transformation? The language for asking and answering this question is provided once again by entropy. And by following the entropic trail we will encounter the all-too-real possibility that the very act of thinking, undertaken by any entity of any kind anywhere, may be thwarted by an unavoidable buildup of environmental waste: in the distant future, anything that thinks may burn up in the heat generated by its own thoughts. Thought itself may become physically impossible.

  While the case against endless thought will be based on a conservative set of assumptions, we will also consider alternatives, possible futures more conducive to life and thinking. But the most straightforward reading suggests that life, and intelligent life in particular, is ephemeral. The interval on the cosmic timeline in which conditions allow for the existence of self-reflective beings may well be extremely narrow. Take a cursory glance at the whole shebang, and you might miss life entirely. Nabokov’s description of a human life as a “brief crack of light between two eternities of darkness”6 may apply to the phenomenon of life itself.

  We mourn our transience and take comfort in a symbolic transcendence, the legacy of ha
ving participated in the journey at all. You and I won’t be here, but others will, and what you and I do, what you and I create, what you and I leave behind contributes to what will be and how future life will live. But in a universe that will ultimately be devoid of life and consciousness, even a symbolic legacy—a whisper intended for our distant descendants—will disappear into the void.

  Where, then, does that leave us?

  Reflections on the Future

  We tend to absorb findings about the universe intellectually. We learn some new fact about time or unified theories or black holes. It momentarily tickles the mind, and if sufficiently impressive, it sticks. The abstract nature of science often leads us to dwell on its content cognitively, and only then, and then only rarely, does that understanding have a chance of touching us viscerally. But on the occasions when science does conjure both reason and emotion, the result can be powerful.

  Case in point: Some years ago when I began to think about scientific predictions regarding the far future of the universe, my experience was mostly cerebral. I absorbed relevant material as a fascinating but abstract collection of insights entailed by the mathematics of nature’s laws. Still, I found that if I pressed myself to really imagine all life, all thought, all struggle, and all accomplishment being a fleeting aberration on an otherwise lifeless cosmic timeline, I absorbed it differently. I could sense it. I could feel it. And I don’t mind sharing that the first few times I went there, the journey was dark. Through decades of study and scientific research, I’ve often had moments of elation and wonder, but never previously had results in mathematics and physics overwhelmed me with a hollow dread.

  Over time, my emotional engagement with these ideas has refined. Now, more often than not, contemplating the far future leaves me with a feeling of calm and connection, as if my own identity hardly matters because it has been subsumed by what I can only describe as a feeling of gratitude for the gift of experience. Since, more than likely, you don’t know me personally, let me put this in context. I’m open-minded with a sensibility that demands rigor. I come from a world in which you make your case with equations and replicable data, a world in which validity is determined by unambiguous calculations that yield predictions matching experiments digit by digit, sometimes as far as a dozen places beyond the decimal point. So the first time I had one of these moments of calm connection—I happened to be at a Starbucks in New York City—I was deeply suspicious. Perhaps my Earl Grey was tainted with some bad soy milk. Or perhaps I was losing my mind.