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

by Brian Greene

Clearly, there is significant survival value in quickly sizing up the nature of our encounters with other life. Researchers call this capacity, refined over generations by natural selection, our theory of mind32 (we theorize, intuitively, that living things are endowed with minds that operate more or less like ours), or the intentional stance33 (we attribute knowledge, beliefs, desires, and thus intentions to the animals and humans we encounter).

The hard problem seems hard—consciousness seems to transcend the physical—only because our schematic mental models suppress cognizance of the very brain mechanics that connect our thoughts and sensations to their physical underpinnings.

Consciousness and Quantum Physics

Take in the number I just quoted: quantum mechanical calculations, based on Schrödinger’s equation, agree with experimental measurements to better than nine digits after the decimal point.

Nevertheless, there is a puzzle at the core of quantum theory.

The challenge, known as the quantum measurement problem, is to resolve the puzzling disparity between the fuzzy quantum reality described by the equations and the sharp familiar reality you consistently experience.

As far back as the 1930s, physicists Fritz London and Edmond Bauer,38 and a few decades later Nobel laureate Eugene Wigner,39 suggested that consciousness might be the key. After all, the puzzle becomes puzzling only when you report on your conscious experience of a definite reality, yielding a mismatch between what you say and what the mathematics of quantum mechanics predicts. Imagine, then, that the rules of quantum mechanics apply all along the chain, from the electron that’s being measured, to the particles in the equipment performing the measurement, to the particles constituting the readout on the equipment’s display. But when you look at the readout and the sensory data flows into your brain something changes: the standard quantum laws cease to apply. Instead, when conscious awareness is brought to bear, some other process takes over—a process that ensures you become cognizant of a single definite result. Consciousness would thus be an intimate participant in quantum physics, dictating that as the world evolves all but one of the many possible futures are eliminated, either from reality itself or at least from our cognitive awareness.

But in my decades of immersion in quantum physics, I have not encountered a mathematical argument or experimental data that have shifted my long-held assessment of the purported link: extraordinarily unlikely. Our experiments and observations support the view that when a quantum system is prodded—whether the prodder is a conscious being or a mindless probe—the system snaps out of the probabilistic quantum haze and assumes a definite reality.

Magnificent though it is, consciousness will be understood as another physical quality that arises in a quantum universe.

Free Will

The mathematics of quantum mechanics, Schrödinger’s equation, is just as deterministic as the mathematics of classical Newtonian physics. The difference is that whereas Newton takes as input the state of the world now and produces a unique state for the world tomorrow, quantum mechanics takes as input the state of the world now and produces a unique table of probabilities for the state of the world tomorrow. The quantum equations lay out many possible futures, but they deterministically chisel the likelihood of each in mathematical stone. Much like Newton, Schrödinger leaves no room for free will.

here and a 50 percent chance of being there. Can you freely pick the outcome—here or there—that an observation of its position will reveal? You can’t. The data attest to the outcome being random, and random outcomes are not freely willed choices.

So although the passage from quantum probabilities to experiential certainties remains puzzling, it is clear that free will is not part of the process.

And since all observations, experiments, and valid theories confirm that particle motion is fully controlled by mathematical rules, we can no more intercede in this lawful progression of particles than we can change the value of pi.

Our choices seem free because we do not witness nature’s laws acting in their most fundamental guise; our senses do not reveal the operation of nature’s laws in the world of particles.

Rocks, Humans, and Freedom

I am free not because I can supersede physical law, but because my prodigious internal organization has emancipated my behavioral responses.

Relevance, Learning, and Individuality

Learning and creativity do not require free will.

Within such higher-level accounts, we speak as though our actions have relevance, our choices have impact, our decisions have significance. In a world progressing via resolute physical law, do they? Yes. Of course they do.

Physics augments this story. Physics tells us that there is another account, underlying the human-level story, told in the language of laws and particles.

Thoughts, responses, and actions matter. They yield consequences. They are the links in the chain of physical unfolding. What’s unexpected based on our experiences and intuitions is that such thoughts, responses, and actions emerge from antecedent causes funneled through the laws of physics.

As my particle arrangement learns and thinks and synthesizes and interacts and responds, it imprints my individuality and stamps my responsibility on every action I take.

And as many who have experimented with mind-altering substances can attest, when the identity of particles coursing through the brain is even modestly modified, the familiar can shift.

We need to set aside the notion that our choices and decisions and actions have their ultimate origin within each of us, that they are brought into being by our independent agencies, that they emerge from deliberations that stand beyond the reach of physical law.

We need to recognize that although the sensation of free will is real, the capacity to exert free will—the capacity for the human mind to transcend the laws that control physical progression—is not.

If we reinterpret “free will” to mean this sensation, then our human-level stories become compatible with the reductionist account. And together with the shift in emphasis from ultimate origin to liberated behavior, we can embra...

Early humans had long since stood up. Now we could look around and wonder. What, then, did we do with such powers?

6

LANGUAGE AND STORY

From Mind to Ima...

Mathematics is the articulation of pattern.

Is mathematics a language humankind developed to describe patterns we encounter? Or is mathematics the source of reality, rendering the world’s patterns the expression of mathematical truth?

First Words

As Bertrand Russell summarized it, “A dog cannot relate his autobiography; however eloquently he may bark, he cannot tell you that his parents were honest but poor.”

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. Still other researchers identify a suite of adaptations including breath control, memorization, symbolic thinking, awareness of other minds, formation of groups, and so on that may have worked in tandem to yield language even though language itself may have had little to do with the survival value of the adaptations themselves.

Artifacts like hafted tools (chiseled stones or bones securely attached to a handle), cave art, geometric engravings, and beadwork provide evidence that our ancestors at least as far back as one hundred thousand years engaged in planning, symbolic thinking, and advanced social interactions.

Scientists tracing the growth of cranial cavities and structural changes in the mouth and throat conclude that if our ancestors were so inclined they may have had the physiological capability to converse well over a million years ago.

Molecular biology provides clues too. Human speech requires a high degree of vocal and oral dexterity, and in 2001 researchers identified what may be an essential genetic basis for such abilities.

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 s...

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.

As skeptical researchers have also noted, it’s one thing to have the physical capability and mental agility to engage in conversation and quite another to actually do so. What, then, may have motivated us to speak?

Why We Spoke

Recent studies have shown that as much as 60 percent of our conversation today is devoted to gossip, a staggering number (especially to those of us who’ve hardly mastered small talk) that some researchers argue reflects the primary purpose of language at its inception.

Storytelling and Intuition

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.

Coding the brain to engage with fiction would thus be a clever way to cheaply, safely, and efficiently give the mind a broader base of experience from which to operate.

Instead of mental file think flight simulator. Stories provide fabricated realms in which we shadow characters whose experiences far outstrip our own. Through borrowed eyes protected by the tempered glass of story, we intimately observe an abundance of exotic worlds. And it is through these simulated episodes that our intuition expands and refines, rendering it sharper and more flexible. When faced with the unfamiliar, we don’t initiate cognitive look-ups that search a Dear Abby of the mind. Instead, through story we internalize a more nuanced sense of how to respond and why, and that intrinsic knowledge guides our future behavior.

Storytelling is our most powerful means for inhabiting other minds. And as a deeply social species, the ability to momentarily move into the mind of another may have been essential to our survival and our dominance.

Storytelling and Other Minds