Until the End of Time:

Mind, Matter and Our Search for Meaning in an Evolving Universe

Brian Greene (2020)

In a paragraph

We explain the universe by constructing narratives that operate at different levels, but which are consistent.  Despite our longing for immortality and the absolute, life and mind are only transitory.

Key points

• We can understand the world through ‘nested naturalism’, using explanatory stories told at different levels with different languages, but consistent with reductionism. Levels include fundamental physics, entropy, evolution and consciousness.

• The universe will play host to life and mind only temporarily. In the distant future, anything that thinks may burn up in the heat generated by its own thoughts.  This cosmological backdrop provides unmatched clarity on how singular and fleeting the here and now actually is.

• Whereas the first law of thermodynamics declares that the quantity of energy is conserved over time, the second law declares that the quality of that energy deteriorates over time.

• The second law is not a law in the traditional sense. It declares only that such a decrease is unlikely. Entropy can decrease. It’s just ridiculously unlikely.

• The entropic two-step, in which the entropy of a system decreases because it shifts a more than compensating increase in entropy to the environment.

• Life needs to deal with energy and entropy.

• Brains that survived are brains that avoided being consumed by details that lacked survival value.

• Our thoughts and behaviours amount to complex processes of shifting particles that yield a powerful sense of free will but are fully governed by physical law. Human freedom is about being released from the bondage of the inanimate world through our sophisticated internal organization which allows for a rich spectrum of behavioural responses.

• Pattern is central to human experience. We survive because we can sense and respond to the rhythms of the world. Mathematics is the articulation of pattern.

• Language may have facilitated internal thought.

• Minds that reason with analogy and metaphor, minds that represent with colour and texture, minds that imagine with melody and rhythm are minds that cultivate a more flourishing cognitive landscape.

• Which news would affect you more – being told you have a year to live or that in a year earth will be destroyed? While one realization seemed to intensify awareness of life’s value, the other seemed to drain it away.

• Certain special collections of particles can think and feel and reflect, and within these subjective worlds they can create purpose.

Comments

An impressive, well-written and absorbing book, setting out a consistent perspective combining elements from physics, biology and philosophy.  The main themes are that we can understand through constructing narratives at different levels, and that life is finite.

Notes

Preface

Every right-angled triangle drawn from before Pythagoras and on to eternity satisfies the famous theorem that bears his name. There are no exceptions. Sure, you can change the assumptions and find yourself exploring new realms, such as triangles drawn on a curved surface like the skin of a basketball, which can upend Pythagoras’s conclusion. But fix your assumptions, double-check your work, and your result is ready to be chiselled in stone. No climbing to the mountaintop, no wandering the desert, no triumphing over the underworld. You can sit comfortably at a desk and use paper, pencil, and a penetrating mind to create something timeless.

In the nearly four decades since, these themes, often simmering on a mental back burner, have stayed with me.

1. The Lure of Eternity Beginnings, Endings, and Beyond

The final fate of any given life is a foregone conclusion. Knowledge that William James described as the “worm at the core of all our usual springs of delight.”

Planet earth, which Carl Sagan described as a “mote of dust suspended on a sunbeam,” is an evanescent bloom in an exquisite cosmos that will ultimately be barren.

Narratives — we have written many nested stories that probe different domains of human inquiry and experience: stories, that is, that parse the patterns of reality using different grammars and vocabularies.  Different stories, told with different languages and focused on different levels of reality, provide vastly different insights.

Much as our biology has been shaped by the forces of Darwinian selection, so too has our behaviour. The brain’s inherited characteristics mould predilections rather than definitive actions.

The possibility that nature will slap down our hubris and reveal surprises.

Ultimately yielding a mist of particles drifting through a cold and quiet cosmos.

 In the distant future, anything that thinks may burn up in the heat generated by its own thoughts.

 Viscerally. A feeling of gratitude for the gift of experience.

 A long lineage that has soothed its existential discomfort by envisioning that we leave a mark.

 The universe will play host to life and mind only temporarily. If you take that in fully, envisioning a future bereft of stars and planets and things that think, your regard for our era can appreciate toward reverence.

 A cosmological backdrop that provides unmatched clarity on how singular and fleeting the here and now actually is.

 In the end, during our brief moment in the sun, we are tasked with the noble charge of finding our own meaning.

2. The Language of Time Past, Future, and Change

The second law of thermodynamics.

Obscures a rich and nuanced progression,

We are saved by a change in perspective.

Large groups often display statistical regularities absent at the level of the individual.

They advocated jettisoning detailed consideration of individual trajectories in favour of statistical statements describing the average behaviour of large collections of particles. They showed that this approach not only makes calculations mathematically tractable, but the physical properties it can quantify are the very ones that matter most. Statistical reasoning.

The entropy of the microstate is the number of such look-alikes.  Commonplace (high entropy) versus rare (low entropy). 

Having more molecules, or having higher temperature, or filling a larger volume results in higher entropy.

The egg and the anthill and the mug each arise from particular forms of life arranging the otherwise random configuration of particles in the environment to yield orderly structures.

Low-entropy configurations should be viewed as a diagnostic, a clue that powerful organizing influences may be responsible for the order we’ve encountered.

Ludwig Boltzmann. 

First law – law of energy conservation.

We associate low entropy with high-quality energy and high entropy with low-quality energy.

Whereas the first law of thermodynamics declares that the quantity of energy is conserved over time, the second law declares that the quality of that energy deteriorates over time.

The second law is not a law in the traditional sense. It declares only that such a decrease is unlikely. Entropy can decrease. It’s just ridiculously unlikely.

A highly ordered, exceedingly low entropy starting point at the big bang is why today’s universe is not entropically maxed out, allowing for an eventful future that differs from the past. Degradation.

 They envisioned a fluidlike substance, called “caloric,” which would flow from hotter locations to cooler ones. When you grasp the pan’s handle, its faster-moving molecules collide with the slower-moving molecules in your hand, on average causing the speed of those in your hand to go up and those in the handle to go down. What flows, then, is not a substance. Molecular agitation flows. Total entropy of a complete physical system, a sense in which entropy can flow.

The entropic two-step, by which I mean any process in which the entropy of a system decreases because it shifts a more than compensating increase in entropy to the environment. The environment must absorb and carry away all the waste, all the entropy, we generate.

3. Origins and Entropy from Creation to Structure

Alan Guth. Repulsive gravity. Inflation field.

4. Information and Vitality from Structure to Life

These better-suited human-level stories must be compatible with the reductionist account. 

Thermodynamic perspective. Redox reaction. Molecular Darwinism. The RNA World proposal. Amino acids. 

The processes of life are molecular meanderings fully described by physical law that simultaneously tell a higher-level, information-based story.

5. Particles and Consciousness from Life to Mind

Cracking consciousness, explaining our inner worlds in purely scientific terms, poses one of our most formidable challenges. 

An explanation of how large collections of particles can coalesce to yield life and generate mind. 

The art of science, of which Newton was the master, lies in making judicious simplifications that render problems tractable while retaining enough of their essence to ensure that the conclusions drawn are relevant.

As powerful as such a description would be, it would remain but one among many stories we tell. 

While a complete reductionist description would provide a scientific bedrock, other descriptions of reality, other stories, provide insights that many deem more relevant because they are closer to experience.

Telling some of these stories, as we’ve already seen, requires new concepts and language. Entropy helps us tell the story of randomness and organization within large collections of particles. Evolution helps us tell the story of chance and selection as collections of molecules — living or not — replicate, mutate, and gradually become better adapted to their environment. 

“Red” is the mind’s welcome, albeit schematic, simplification. 

Schematic representation is not only adequate but also frees up mental resources. Brains that survived are brains that avoided being consumed by details that lacked survival value. 

Theory of mind. Intentional stance. 

Sketches the attention itself, what in common language we normally call our “awareness.” 

Consciousness would be demystified without being diminished. 

My focus here is not on predicting your next move. My focus is on the existence of laws that govern your next move. 

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. 

Our thoughts and behaviours amount to complex processes of shifting particles that yield a powerful sense of free will but are fully governed by physical law. 

Your sophisticated internal organization allows for a rich spectrum of behavioural responses. Human freedom is about being released from the bondage of an impoverished range of response that has long constrained the behaviour of the inanimate world.

Enlightening to tell additional stories, compatible with the reductionist account, but focused on larger and more familiar scales. These stories, whose main characters are aggregates of particles. The higher-level story, the human story, is the one by which we live our lives.

When I have dinner with my wife, I am just not that interested in listening to an account of the motion carried out by her hundred billion particles. However, when she tells me about the ideas she is developing, places she is going, and people she is meeting, I am all in. 

Physics does not drain this story of relevance. Physics augments this story.

6. Language and Story from Mind to Imagination

Pattern is central to human experience. We survive because we can sense and respond to the rhythms of the world. 

Mathematics is the articulation of pattern. Galileo summed it up by declaring that the book of nature, which he believed revealed God just as surely as the Bible, is written in the language of mathematics.  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? 

Rare was the meal, and rarer still was the opportunity to reproduce, that our ancestors secured by contemplating prime numbers or squaring the circle. 

I make progress in physics by fiddling with equations and collecting conclusions in ordinary sentences I write out longhand in notebooks that fill one shelf after another. 

I have no doubt that there are vital qualities of thought and experience that stand outside language but without language my capacity for certain kinds of mental manoeuvres would diminish. 

Toni Morrison, “We die. That may be the meaning of life. But we do language. That may be the measure of our lives.” 

We can pass on hard-earned knowledge, substituting the ease of instruction for the difficulty of discovery.  Immensely consequential communal force. 

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) 

Give individuals the power to guide each other’s imaginations. Language may have facilitated internal thought. Language and thought provide a potent mix.

Michel Jouvet, the dream world of cats. When cats and rats dream it surely seems they’re rehearsing behaviours relevant to survival. 

Einstein’s bold quest had arrived safely on the shores of understanding.

Flight simulator of story. Craving for understanding. Our minds are adapted for painting the universe in story.

The raison d’être of science is to pull back the veil obscuring an objective reality,

That is the power but also the limitation of science.   Rigorously adhering to a standard that minimizes subjectivity,

Myths —larger than life but minimally counterintuitive constructs of the human imagination.

7. Brains and Belief from Imagination to the Sacred

Dreams providing windows onto unseen realities.

“New zest which adds itself like a gift to life and takes the form of either lyrical enchantment or of appeal to earnestness and heroism.”

 Evolution did not configure our brain processes to form beliefs that align with reality. It configured them to favour beliefs that generate survival-promoting behaviours.

8. Instinct and Creativity from the Sacred to the Sublime

Sensitivity to pattern ranks among our most potent survival skills.

“Without art, the crudeness of reality would make the world unbearable.”

Sexual selection. Whether mate choice is driven by aesthetic sensitivities or by health evaluations, the resulting preferences can provide a rationale for costly traits, boy meets girl, artistic talent may have determined whether boy went home alone.  Human artistic capacities provide a fitness indicator.

The arts, according to Pinker, are adaptively useless creations designed to artificially excite human senses that evolved to promote the fitness of our ancestors.  In Pinker’s view, the arts cut the feedback loops, sever adaptive benefits, and directly stimulate our pleasure centres,

Music is an auditory parasite, free riding on emotionally evocative aural sensitivities. Music hijacks such sonic sensitivity and takes it for a joyride of sensual pleasure that confers no adaptive value.

“Art has been about stirring up and shaping the emotions in a way that binds and inculcates those under its sway as participants in a culture.”

Minds that reason with analogy and metaphor, minds that represent with colour and texture, minds that imagine with melody and rhythm are minds that cultivate a more flourishing cognitive landscape.

Crack our rigid perspective on space and time.

Artistic endeavours may have been the playground of human cognition, providing a safe arena for training our imaginative capacities.  Sharpening innovation and strengthening social bonds. 

While my own working process is thoroughly language based, I feel no urge to explore these experiences in words. When I think of them, I feel no lack of understanding calling out for linguistic clarification.

The most arresting art can induce in us rarefied states of mind and body comparable to those produced by our most affecting real-world encounters.

“When a writer brings into language a new image that is fully right, what is knowable of existence expands.”

Visual and auditory works, in which language is not central, provide experiences that are more impressionistic. These heightened encounters provide insights that would be difficult if not impossible to otherwise acquire. Song makes you feel a thought.

Poetic immortality.  Sappho lamented the inevitability of change, “You, children, pursue the violet-laden Muses’ lovely gifts / and the clear-toned lyre so dear to song; / but for me — old age has now seized my once tender body,”

 Lifelong project of shaping its own idiosyncratic self. The artist moves toward psychic health by accepting mortality — we’re going to die, that’s that, get over it — and shifting the urge for eternity onto a symbolic form carried by creative works.

When I asked why he chose music, my dad answered, “To keep away the loneliness.”

9. Duration and Impermanence from the Sublime to the Final Thought

We revere the absolute but are bound to the transitory. 

The second law of thermodynamics is a general consequence of applying statistical reasoning to the underlying physical laws. 

The broad behavioural repertoire of intelligence — makes certain varieties of prediction essentially impossible.

I don’t mind your thinking slowly; I mind your publishing faster than you think.

10. The Twilight of Time Quanta, Probability, and Eternity

Freeman Dyson. John Wheeler.

Entropy counts the distinct configurations of a system’s microscopic constituents that are compatible with its macroscopic state.

 “Quantum tunnelling.” Just as quantum mechanics allows an electron occasionally to tunnel out of a trap, so too does it allow for the value of the Higgs field to tunnel through a barrier.  The next moment we would cease to be.

11. The Nobility of Being Mind, Matter, and Meaning

Nature is lawful — The equations at the core of modern physics represent our most precise statement of the laws.

We employed our cognitive capacities to go beyond such survival-promoting intuitions. Much as natural selection shaped our intuition for basic physics, it also had a hand in shaping our innate sense of morality and value.

Some suggest that, similar to the developmental pattern for physics, evolution imprinted a rudimentary moral sense, but our cognitive powers have allowed us to leap beyond that innate base to fashion independent attitudes and beliefs.

Others suggest that we are adept at using our cognitive dexterity to explain our moral commitments, but these accounts are just-so stories, rationalizations of judgments anchored in our evolutionary past.

The deeply personal dilemma is that self-aware somethings, like us, subsequently dissolve into nothing.

To conclude that we would necessarily grow bored suggests an unduly parochial vision of the immortal mind.

The deep-seated knowledge that there are just so many mornings when we will rise at all instils an intuitive calculus of value,

“Which news would affect you more,” she asked, “being told you have a year to live or that in a year earth will be destroyed?” While one realization seemed to intensify awareness of life’s value, the other seemed to drain it away. We need humanity to have a future for the very idea that things matter to retain a secure place.

Even if a given physics paper I write does not set the world on fire, the paper nevertheless makes me feel part of the conversation.

Our moment is rare and extraordinary.

How utterly wondrous it is that a small collection of the universe’s particles can rise up, examine themselves and the reality they inhabit, determine just how transitory they are, and with a flitting burst of activity create beauty, establish connection, and illuminate mystery.

Life and mind are simply a couple of things that happen to happen. Until they don’t.

To see our moment in context is to realize that our existence is astonishing.

What Richard Dawkins described as the nearly infinite collection of potential people, would-be carriers of the nearly infinite collection of base pair sequences in DNA, none of whom will ever be born. How spectacularly unlikely. How thrillingly magnificent.

Whereas most life, miraculous in its own right, is tethered to the immediate, we can step outside of time.

Why is there something rather than nothing? What sparked the onset of life? How did conscious awareness emerge?

Perhaps, as our intelligence continues to evolve, our engagement with reality will acquire a wholly different character, with the result that today’s towering questions become irrelevant.

Certain special collections of particles can think and feel and reflect, and within these subjective worlds they can create purpose.

Notes

Alan Guth, The Inflationary Universe

The more intuitive problem of identifying the outward push

Principle of indifference.

The likelihood of one microstate versus another is then determined by the ratio of the number of microstates that yield each.

The inflationary phase to be initiated by a quantum-tunnelling event

Cosmic horizon

Because searches for dark matter particles have so far come up empty–handed, some researchers have suggested alternatives to dark matter in which observations are explained through modifications of the gravitational force law.

Nested stories “levels of understanding” “levels of explanation,”

Naturalism — “scientism.” “expansive or open-minded naturalism” “pluralistic naturalism,” “diverse and overlapping projects of inquiry” “model dependent realism,” “poetic naturalism,”“nested naturalism.”

Committed to the value and the universal applicability of reductionism. But depending on the questions being pursued, these other explanatory stories can provide accounts that are far more insightful than the one provided by reductionism.

All of the accounts must be mutually consistent, but new and useful concepts can emerge at higher levels that do not admit lower-level correlates.

“language serves not only to express thoughts, but to make possible thoughts which could not exist without it” Bertrand Russell

Pascal Boyer, Religion Explained: The Evolutionary Origins of Religious Thought

Multilevel selection.

Freeman Dyson, “Time without end: Physics and biology in an open universe

Even Einstein’s bad ideas are good.

Inflationary multiverse.