Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe

by Brian Greene

“I often think in music,”1 is how he described it. “I very rarely think in words at all.”2 Perhaps your process mirrors Einstein’s.

Cognitive psychologists Steven Pinker and Paul Bloom, pioneers of a Darwinian approach to language, suggest a less bespoke history, one in which language emerged and developed through the familiar pattern of a gradual buildup of incremental changes that each conferred a degree of survival advantage.12 As our hunter-gatherer forebears roamed the plains and forests, the capacity to communicate—“Group of wild boar grazing at eleven o’clock,” or “Watch out for Barney, he’s got his eye on Wilma,” or “Here’s a better way of attaching that sharpened stone to the handle”—was vital for effective group functioning and essential for sharing accumulated knowledge. Brains capable of communicating with other brains thus had an edge in the competitive arena of survival and reproduction, impelling linguistic capacities to refine and spread widely.

Studying a British family with a speech disorder spanning three generations—difficulty with grammar and with coordinating the complex movements of mouth, face, and throat necessary for normal speech—researchers homed in on a genetic mishap, a change to a single letter in a gene called FOXP2 sitting on human chromosome 7.14 The instructional misprint is shared by the afflicted family members and has thus been strongly implicated in the disruption of both language and speech. Early press coverage of the discovery dubbed FOXP2 the “grammar gene” or the “language gene,” headline-grabbing descriptions that irked informed researchers, but oversimplified hyperbole aside, the FOXP2 gene does appear to be one essential component for normal speech and language. Intriguingly, close variations of the FOXP2 gene have been identified in many species, from chimps to birds to fish, allowing researchers to trace how the gene has changed over evolutionary history. For chimps, the protein encoded by their FOXP2 gene differs from ours by only two amino acids (out of more than seven hundred), while that of Neanderthals is identical to ours.

Yet, should gesturese leave you skeptical, consider evolutionary psychologist Robin Dunbar’s proposal that language emerged as an efficient substitute for the widely practiced activity of social grooming.

Today’s craving for pistachio Häagen-Dazs, no longer praised as a health promoter, is a modern relic of yesteryear’s vital scavenging for calories. It’s Darwinian selection manifested at the level of behavioral inclination. Not that genes determine behavior. Our actions result from a complex amalgam of biological, historical, social, cultural, and all manner of chance influences that are imprinted on our particle arrangement. But our tastes and instincts are an essential part of that mix, and in the service of enhanced survival evolution had a strong hand in shaping them. We can learn new tricks but, genetically and hence instinctually speaking, we are old dogs.

As intelligence matures, the very same impulse to explore and to understand manifests as an urge to infuse experience with significance. Answer enough how questions and why questions quickly follow.

Dreamlike trance states are also common to a number of traditions that engage in rituals driven by percussive music and strenuous dance, which can proceed for hours and induce hypnotic reveries that participants have described as being transported to distinct planes of reality.

Emotion has been enmeshed throughout our evolutionary development.

“Without music,” said Friedrich Nietzsche, “life would be a mistake.”

If creating and consuming works of the imagination were a recent addition to human behavior, or if these activities were only rarely practiced across human history, it is unlikely that they would reveal universal qualities of our evolved human nature. After all, some things—like bell-bottoms and fried bananas—arise from contingent peculiarities, and so teasing out the details of their historical lineage offers only limited enlightenment. But the fact is, far into the past and clear across lands inhabited, we have been singing and dancing and composing and painting and sculpting and carving and writing. Cave paintings and elaborate burial goods, as encountered in the previous chapter, date from as far back as thirty to forty thousand years ago. Etchings and artifacts that show evidence of artistic expression have been discovered from a few hundred thousand years earlier.5 We are faced with a behavior that is pervasive and yet, unlike eating and drinking and procreating, doesn’t wear its survival value on its sleeve.

But if we don’t invoke an innate sensitivity to beauty, how do we explain the lavish bodily adornments, creative displays, and physical constructions that are integral to myriad mating games playing out in the animal kingdom? Well, there is a less lofty approach. Consider again the peacock’s tail. While we humans may appreciate the aesthetics of a peacock’s plumage, to a peahen it may arouse an instinctual response of considerable genetic importance. Peacocks adorned with dazzling plumage are strong and healthy, increasing the likelihood that they will sire hardy offspring. And since peahens, much as the females in most species, can produce far fewer progeny compared to their male counterparts, they have developed an especially strong preference for fit males; such unions enhance the success rate of each resource-consuming and hence precious fertilization.11 With rich plumage being a visible demonstration of a potential mate’s strength and vigor, peahens attracted to such tails are more likely to spawn robust peachicks. These peachicks, in turn, will on average be endowed with the very genes for desiring and acquiring resplendent plumage, facilitating the spread of such traits through future generations. Beauty, in this analysis of sexual selection, is a good deal more than skin-deep. Beauty amounts to publicly available credentials attesting to a potential mate’s adaptive fitness.

If aliens visited Paleolithic earth and wagered on who’d be top dog a million years later, genus Homo may not have inspired many bets. However, by pooling brawn and brain, we were able to prevail over forms of life larger, stronger, and faster, as well as those endowed with more refined senses of smell, sight, and sound. We triumphed because we are resourceful and creative, certainly, but above all because we are exceptionally social.

The arts provide an arena unbounded by the strictures of flat-footed truth and everyday physical reality, allowing the mind to jump and twist and tumble as it explores all manner of imagined novelty. A mind that assiduously sticks to what’s true is a mind that explores a wholly limited realm of possibility. But a mind that becomes accustomed to freely crossing the boundary between what’s real and what’s imagined—all the while keeping clear tabs on which is which—is a mind that becomes adept at breaking the bonds of conventional thinking. Such a mind is primed for innovation and ingenuity. History makes this manifest. We owe many of the greatest breakthroughs of science and technology to a collection of individuals who were able to look at the very same problems that had confounded generations of previous thinkers and have the flexibility of thought to see those problems differently.

That Einstein described his intellectual process as thinking with music and that he frequently relied on visual explorations free of equations and words perhaps isn’t all that surprising. Einstein’s art was to hear rhythms and see patterns that revealed deep unity in the workings of reality.

Note too that the adaptive roles for art we’ve considered—sharpening innovation and strengthening social bonds—work in tandem. Innovation is the foot soldier of creativity. Group cohesion is the army of implementation. Success in the relentless battle for survival requires both: creative ideas that are successfully implemented. That the arts stand at the nexus of the two suggests an adaptive role beyond the mere pushing of pleasure buttons. Sure, it’s possible that the arts are an adaptively inconsequential yet profoundly pleasing by-product of a large brain hosting a creative mind, but to many researchers that gives insufficient heed to art’s capacity to sculpt our engagement with reality. Brian Boyd has made this point succinctly: “By refining and strengthening our sociality, by making us readier to use the resources of the imagination, and by raising our confidence in shaping life on our own terms, art fundamentally alters our relation to our world.”

The lyricist Yip Harburg, author of many classics including “Over the Rainbow,” said it simply: “Words make you think a thought. Music makes you feel a feeling. But a song makes you feel a thought.”22 Feel a thought. For me, that captures the essence of artistic truth. As Harburg emphasized, thinking is intellectual, feeling is emotional, but “to feel a thought is an artistic process.”23 It is an observation that rests on linking language and music but, really, it yokes the arts more generally. The emotional responses elicited by art ripple across the reservoir of churning thought that underlies conscious awareness.

A brilliant aurora borealis filled the night sky. I had never seen anything like it. The swirling gossamer strands of light, the stunning colors bleeding one into another, all set against a backdrop of seemingly endless, uncountable stars. Suddenly, I was in a different place. The hike, the swamp, the cold, the near-naked huddling—it was all now part of a primordial throwback. Man, nature, universe. While I wore earth, I was enveloped in the dancing lights. Abandoned by the last of our communal heat, I was absorbed by the distant stars. I lost track of how long I stared at the sky before drifting off to sleep, whether minutes or hours. Duration didn’t matter. For a brief moment, time had dissolved. Episodes with this timeless quality are rare. And they are fleeting.

The center of the sun is where you find its hottest temperatures, currently about fifteen million degrees, well in excess of the ten million degrees required to fuse hydrogen into helium. But to fuse helium nuclei requires a temperature of about one hundred million degrees. Because the sun’s temperature is nowhere near that threshold, as helium displaces hydrogen in the core, fusion’s fuel supply will dwindle. The outward pressure from fusion’s production of energy in the core will subside, and consequently the inward pull of gravity will gain the upper hand. The sun will begin to implode. As its spectacular heft collapses inward, the sun’s temperature will skyrocket. The intense heat and pressure, still shy of the conditions necessary for helium to start burning, will spark a new round of fusion within a thin shell of hydrogen nuclei surrounding the helium core. And with such extreme conditions, hydrogen fusion will proceed at an extraordinary pace, producing a more intense outward push than the sun has ever experienced, not only halting the implosion but thrusting the sun to swell tremendously.

It makes you wonder: assuming that the data we’ve gathered, establishing that the universe is expanding, were to somehow be preserved and delivered to the hands of astronomers a trillion years from now, would they believe it? Using their state-of-the-art equipment, a trillion years in the making, they will see a universe that on the largest of distances is black, about as eternal and unchanging as it gets.

Astronomers use the catchall name red dwarf to label an assortment of such low-mass stars, and according to observations they likely account for the majority of stars in the universe.

Looking up at a clear night sky gives the impression that the galaxy is dense with stars. It’s not. Although it seems like stars are arranged cheek by jowl on a sphere that surrounds us, because their distances from earth vary widely—a feature that’s mostly lost on our feeble, closely set eyes—stars are, in reality, quite far from one another. Were you to shrink the sun down to the size of a grain of sugar and place it at the Empire State Building, you’d have to drive most of the way to Greenwich, Connecticut, to encounter Proxima Centauri, our nearest stellar neighbor.

Fully determined by just three numbers and consisting of mostly empty space (everything that falls into a black hole is drawn relentlessly toward its central singularity), black holes had acquired an aura of utter simplicity.

Instead, the calculations led Hawking to a conclusion so shocking that it took him some time to believe it. Hawking’s analysis not only confirmed Bekenstein’s, but also revealed complementary surprises: black holes have a temperature and black holes glow. They radiate. Black holes are black in name only. Or, said more precisely, black holes are black only if you ignore quantum physics.

Even if the region appears empty, seemingly containing no energy at all, quantum theory shows that its energy content actually rapidly fluctuates up and down, yielding zero energy only on average. These are the same type of quantum fluctuations that gave rise to the temperature variations in the cosmic microwave background radiation that we encountered in chapter 3. Through E = mc2, such quantum energy fluctuations can also show up as quantum mass fluctuations—particles and their antiparticle partners popping into existence in otherwise empty space. This is happening right now in front of your eyes, yet however intently you stare you’ll see no evidence of it. The reason is that quantum mechanics also dictates that such particle-antiparticle pairs quickly find each other, annihilate and fade back into empty space. We do detect indirect signatures of these ephemeral machinations because it is only when we include them in our calculations that we achieve the stunning agreement between predictions and measurements that has justifiably made quantum mechanics the centerpiece of fundamental physics.7 Hawking revisited these quantum processes but now imagined them taking place just outside the event horizon of a black hole. When a particle-antiparticle pair pops into this environment, sometimes the two particles will annihilate quickly, just as they would anywhere else. But, and this is the point, Hawking realized that on occasion they will not annihilate. Sometimes one member of ...

As the black hole consumes these negative mass particles, it’s as if it is eating negative calories, resulting in its mass going down, not up. Viewed from the outside, the black hole thus appears to steadily shrink as it radiates particles. Were it not that the source of the radiation is exotic—a black hole immersed in the quantum bath of fluctuating particles inherent in empty space—the process would appear thoroughly pedestrian, like a glowing chunk of charcoal radiating photons as it slowly wastes away.

In the fullness of time, black holes will waste away too.

As astronomical surveys have progressed, each record holder has been unseated by the next, with champion masses heading toward one hundred billion times that of the sun. A black hole of that mass has an event horizon so large that it would stretch from the sun past the orbit of Neptune and a fair way toward the Oort cloud. Even if you’re a bit rusty on Oort and his distant cloud, just know that it takes sunlight well over one hundred hours to reach it, so we are talking about a black hole with a monstrous span.

To turn a grapefruit into a black hole, you’d need to squeeze it down to about 10−25 centimeters across; to turn the earth into a black hole you’d need to squeeze it down to about two centimeters across; and for the sun, you’d need to squeeze it to about six kilometers across.

It is a cosmic version of dust to dust, with the early dust primed to dance the entropic two-step, being driven by gravity into orderly astronomical structures, while the later dust, spread so thinly, will be content to drift quietly through the void.

At a press conference on July 4, 2012, held at CERN, the European Center for Nuclear Research, spokesperson Joe Incandela announced the discovery of the long-sought Higgs particle. I was watching the live feed at the Aspen Center for Physics in a room packed with colleagues. It was about two a.m. Everyone erupted into wild cheers. The camera cut to Peter Higgs, removing his glasses and wiping his eyes. Higgs had proposed the particle bearing his name nearly fifty years earlier, had successfully fought the resistance unfamiliar ideas sometimes encounter, and had waited a lifetime to learn that he was right.

He argued that, intrinsically speaking, particles are massless, just as the pristine symmetric equations required. However, Higgs continued, when thrust into the world, the particles acquire mass through an environmental influence. Higgs envisioned that space is filled with an invisible substance, now called the Higgs field, and that particles pushed through the field experience a drag force somewhat like that experienced by a Wiffle ball flying through air. Even though a Wiffle ball weighs next to nothing, if you hold it outside the window of a car revving up to ever-higher speeds, your hand and arm will get quite a workout: the Wiffle ball feels massive because it is plowing through the resistance exerted by the air. Similarly, Higgs proposed, when you push on a particle it feels massive because it is plowing through the resistance exerted by the Higgs field. The more hefty a particle the more it resists your push, which according to Higgs means the particle experiences a stronger resistance from his space-permeating field.

Similarly, if you place an electron in a trap shaped like a tiny champagne flute, hemming in its position with barriers on all sides, you would expect that it too would remain in place. Indeed, most of the time the electron does. But sometimes it doesn’t. Sometimes the electron disappears from the trap and rematerializes outside it. Surprising as such a Houdini-like move may be for us, in quantum mechanics it is business as usual. Using Schrödinger’s equation, we can calculate the probability that an electron will be found in this or that location, such as on the inside or on the outside of the fluted trap. The math shows that the more formidable the trap—the taller and thicker the sides—the smaller the likelihood that the electron will escape. But, and this is key, for the probability to be zero, the trap would need to be infinitely wide or infinitely high, and in the real world that just doesn’t happen. And a nonzero probability, however small, means that by waiting long enough, sooner or later the electron will make it to the other side. Observations confirm that it does. Such a transit through a barrier is what we mean by “quantum tunneling.”

This entails a peculiar conclusion: the reality that you and I and everyone else experiences is happening out there in other regions—in other universes—over and over again.

But the rhythm of birth and death, emergence and disintegration, creation and destruction that we’ve witnessed playing out along the timeline will persist. The entropic two-step and the evolutionary forces of selection enrich the pathway from order to disorder with prodigious structure, but whether stars or black holes, planets or people, molecules or atoms, things ultimately fall apart. Longevity varies widely. Yet the fact that we will all die, and the fact that the human species will die, and the fact that life and mind, at least in this universe, are virtually certain to die are expected, run-of-the mill, long-term outcomes of physical law. The only novelty is that we notice.

We are ephemeral. We are evanescent. Yet our moment is rare and extraordinary, a recognition that allows us to make life’s impermanence and the scarcity of self-reflective awareness the basis for value and a foundation for gratitude.