The Order of Time — a Rovelli companion.

1. The book in one paragraph

The Order of Time is the book in which a working theoretical physicist describes, for general readers, the surprising fact that time as we experience it does not appear in fundamental physics. The book opens with the easy losses (time isn't absolute, time isn't universal, the present moment isn't well-defined across observers), proceeds through the deeper losses (time isn't continuous; the direction of time is statistical, not a law), and ends with the most radical position Rovelli will commit to in print: that time is not a thing that exists at all. It is the name of a pattern of relationships between events, a pattern that becomes apparent only when an observer is too small to track all the degrees of freedom in their environment. The book is short, lyrical, and surprisingly accessible given the technical commitments behind it. It is also, as this essay will argue, almost a working physicist's prequel to the trilogy.

2. The four standard claims — and what the trilogy needs from each

Time is not absolute.

Einstein established this in 1905 and 1916, and Rovelli walks through it carefully. Clocks run slower in stronger gravitational fields. Clocks run slower when moving relative to an observer. Two events that are simultaneous for one observer are not simultaneous for another moving relative to them. There is no master clock anywhere in the universe. For the trilogy, this is necessary background: the receiver model's field cannot be located in some Newtonian universal time, because there isn't one. The field must be compatible with relativity, and Rovelli's framework shows what compatibility looks like.

Time is not continuous.

Below the Planck time (~5.4 × 10^-44 seconds), the concept of "duration" ceases to apply in any sensible way. Loop quantum gravity, the program Rovelli has spent his career on, predicts that time itself comes in quanta — that there is a smallest possible interval, and below it, time as a continuous parameter dissolves into a discrete network of events. See the Planck-scale page for the parallel arguments from other directions (string theory's T-duality, the generalized uncertainty principle, black-hole thought experiments). For the trilogy: the universe is rendered at finite resolution not only in space but in time. What we experience as a continuous flow is a coarse-grained view of a discrete underlying structure, just as a smooth video is a coarse-grained view of discrete frames.

The present moment doesn't exist universally.

Different observers have different "nows." At galactic distances, the concept of a simultaneous "now" loses meaning entirely — there are events on the other side of the galaxy whose temporal relationship to your current moment is undefined within any choice of reference frame. The "present" is a local construction of each observer, not a property of the universe. For the trilogy this dissolves a problem the receiver model would otherwise have to solve. If consciousness is a field, where is the field "now"? On Rovelli's view, the question doesn't apply. The field doesn't have a "now." Localized observers have nows, each one slightly different. The field is the substrate of those nows, not one of them.

Time's direction is an illusion (in a specific sense).

The microscopic laws of physics are time-symmetric. Reverse the equations and they describe a perfectly valid alternative process. The asymmetry of time we experience — eggs breaking but never reassembling, memories of the past but not the future — comes from statistics, specifically from the second law of thermodynamics. The second law in turn comes from the fact that the universe started in a wildly improbable low-entropy state (Penrose's number, 1 in 10¹⁰¹²³). Without that initial condition, there is no arrow. The arrow is a fact about our cosmic neighbourhood, not a fact about the laws of physics. For the trilogy: the symmetric-300-ms architecture, Lucía's pre-event window, the time-symmetric quantum mechanics the books rest on (TSVF, Wheeler delayed-choice) are all coherent inside Rovelli's framework. The forward arrow we experience is the felt quality of being a localized observer; it is not a fact about reality at the fundamental level.

3. Relational time — Rovelli's deeper claim

The four standard claims are not original to Rovelli; they are the consensus of post-Einstein physics, well established. The deeper move in the book — the move that most popular accounts don't make — is to argue that time is relational. Going back to Leibniz and Mach, the claim is that time is not a thing that exists. It is the name for a pattern of relationships between events. Take away the events and there is no time waiting around to be filled.

This is not a mystical claim. It is the standard view in general relativity (where time is geometry, not a backdrop) and the consensus view in quantum gravity (where time emerges from the relationships among quantum states, not from a master clock). It is the natural reading of the Wheeler-DeWitt equation, the central equation of quantum cosmology, which famously contains no time variable at all. The universe, in that equation, simply is — a frozen pattern of relationships from which the appearance of flow emerges only when an observer is embedded within it.

For the trilogy this answers a question the receiver model otherwise leaves dangling: where is the field "located" in time? On Rovelli's view, the question doesn't apply. The field isn't in time; time is in the field, as one of the patterns the field's interactions produce. The field as a whole has no time. Local concentrations of the field — brains, bodies, planets, galaxies — produce local time as a feature of their interactions with their neighbours. Time is not a stage on which the field acts. Time is what the field's actions look like from inside a particular localization.

Read · Association as Causation: The Fabric of Meaning and Existence Itself ↗ · Stephen Jarosek, Essentia Foundation (May 2026) · an essay arguing that association — the relational tie between elements — is not a description laid over the world but the irreducible principle of which causation, coherence, and meaning are all expressions. Jarosek weaves four lineages into one thesis: Carlo Rovelli's Relational Quantum Mechanics (particle properties exist only in interaction, never intrinsically); Michael Levin's cellular intelligence (memory and pattern-recognition held collectively in bioelectric networks rather than in any single cell — see the Levin companion page); Charles Sanders Peirce's triadic semiotics (meaning as the association of sign, object, and interpretant); and the Buddhist śūnyatā tradition (emptiness not as absence but as the creative openness from which form arises). Jarosek aligns the synthesis explicitly with Bernardo Kastrup's idealism — reality as a web of meaningful relations across scales rather than a collection of isolated objects. The claim that association is axiomatic, ontologically prior to the things it relates, is the metaphysical generalization of what Rovelli proves locally for time, and it sits naturally beside the trilogy's receiver model: Anima's edge cases — a patient's lucidity returning as the cellular network thins, a dog anticipating an arrival before any sensory cue — are exactly the kind of phenomenon Jarosek's framework predicts as primary rather than anomalous. The receiver model and Jarosek's "association as causation" arrive at the same architecture from different vocabularies.

4. Thermal time — Rovelli's own technical contribution

Rovelli's most original contribution to the foundations of physics, made jointly with Alain Connes in the 1990s, is the thermal time hypothesis. It is the most technically substantial argument in the book, and the one most worth understanding for the trilogy.

The hypothesis: at the fundamental level there is no time. There is only a static quantum state of the universe. What we experience as time is a statistical phenomenon that emerges when an observer cannot track all the degrees of freedom in their environment. The observer averages over the unknown variables; the average has a natural temperature; and a thermal state has a natural time evolution associated with it (this is a deep mathematical fact about the structure of thermodynamics, called the Tomita-Takesaki theorem). Time, in this picture, is the parameter generated by the observer's ignorance.

If you could see every degree of freedom in your environment — every particle, every field configuration, every entanglement structure — time would dissolve. You would see a static pattern of correlations, with no preferred direction and no flow. Because you can't, because you are necessarily a coarse-grained sampler, you experience the irreversible flow of time as a statistical bias. Time is what your ignorance feels like.

For the trilogy this is enormously useful. It says: time is what consciousness experiences when it has localized into a coarse-graining of the field. The field itself, having access to (being identical to) all the degrees of freedom, has no time. Brains have time because brains are necessarily coarse-grained samplers of the field. When the localization releases — death, deep meditation, terminal lucidity, NDE-states — the experience of time should change, and it does. The reports across these very different phenomena converge on the same description: a single recovered moment, timelessness, simultaneity of one's life. Rovelli's framework plus the receiver model would predict exactly this convergence.

5. Memory creates the past

Rovelli is explicit that what we call "the past" is a construction of memory. Without memory, there is no past — there are only events at various distances from current observation, with no preferred direction. The directional flow we experience is the brain's reading of its own memory traces; the brain is what links discrete observations into a continuous sequence.

This connects directly to vertical samsara as the trilogy frames it. The wave pattern persists in the field because the field has its own kind of memory — the persistent pattern — and individual lives are localized samplings of that field-memory. Stevenson's past-life cases, terminal lucidity, the persistence of consciousness across substrate changes — all of these become tractable if memory is a fundamental feature of the field rather than a brain-only phenomenon. The brain's memory is local, fragile, dependent on neural tissue. The field's memory is non-local, persistent, what the trilogy calls "remembered in the field." Two kinds of memory, both real, both implied by Rovelli's framework.

Note how cleanly this dissolves a problem that troubles materialist accounts of memory. If memory is just neural traces, then memory cannot survive the brain. If memory is a feature of the field that the brain reads and writes, then memory can survive the brain — but only as patterns in the field, not as the personal memories of the deceased. Stevenson's cases, where children remember the verifiable specific experiences of a previous person, look exactly like field-memory being read by a new localization. The trilogy treats this as the natural reading. Rovelli supplies the physics that makes it coherent.

6. Nested simulations and their location in time

This is the most interesting place to apply Rovelli's framework to the trilogy, and the question that prompted this companion. The standard worry about nested simulations is that "time" must run somewhere — there has to be a master clock at the top, ticking out simulation steps, and everything else is downstream. If you take Rovelli seriously, this worry dissolves entirely.

Time is local to each system. A simulation has its own time, defined by the rate of state-transitions within the simulation. The simulator has its own time, defined by the rate of state-transitions in the substrate the simulator runs on. There is no canonical relationship between the two. One second of simulator time could correspond to a billion years of simulated time, or to a microsecond, or to no simulated time at all (if the simulator is paused). The simulated inhabitants would not be able to detect this. From the inside, the simulation's time is simply their time, generated by their own thermal-time relationship to their own degrees of freedom.

This is exactly the setup Anima needs for the Young Person at the console. The Young Person is in a different simulation level than José. There is no shared "now" between them. José's lifetime might correspond to seconds for the Young Person, or to many of their lifetimes. The Young Person's lifetime might in turn be only seconds — or only formal computational steps — in the simulation above them, and so on. The hierarchy of nested simulations is not a tree in some master timeline. It is a hierarchy of coarse-grainings, with each level having its own emergent time, none of them privileged, none of them sharing a clock with the others.

This also resolves a problem the trilogy gestures at but doesn't formally state: how can Lucía perceive into what we call her "future" if the universe has a definite forward arrow? Answer: it doesn't. Each localized observer has an emergent forward arrow, but the field itself does not. A consciousness partially coupled to a wider region of the field (Lucía in a particular way; Sable more thoroughly) has access to information from a wider temporal slice. What looks like premonition from inside a single localization is simply normal access to a wider patch of the field's pattern from a less-localized vantage. No physics is violated. No retrocausal signal is sent. The receiver is wider. Rovelli supplies the physics in which a "wider receiver" can mean exactly that — less coarse-graining, more degrees of freedom directly available — without requiring any new principle of physics.

7. The block universe, vertical samsara, and the LQG quanta

The block universe view — all moments equally real, no flowing "now" — is consistent with both Einstein's relativity and Rovelli's loop quantum gravity. Rovelli is somewhat ambiguous about whether he is a strict block-universe theorist (he leans toward the relational view, which is subtly different) but in either reading, the trilogy's vertical samsara — successive lives as edits of the same underlying pattern — fits naturally. The pattern doesn't move through time; it has temporal extent across the block (or across the relational network), and what looks like sequence (life → death → next life) is the field reading and rewriting different temporal segments of the pattern. This is closer to how memory works in a hologram than how memory works in a video file.

The loop quantum gravity programme also gives the trilogy's "rendered at finite resolution" thesis a concrete formal grounding. In LQG, space and time both come in quanta. Below the Planck scale, neither concept makes sense; the world is a network of discrete events linked by quantized geometric relationships. What we experience as smooth spacetime is the coarse-grained limit of this discrete underlying structure — exactly the architecture the trilogy ascribes to the rendered universe. Rovelli's quanta are the trilogy's pixels, worked out mathematically.

Notice how the trilogy's musical motifs sit naturally inside this picture. The φ-tuned chord, the cymatic patterns Lucía perceives, the Webb triangle — all are discrete frequency relationships, exactly the kind of pattern a quantized spacetime would express most directly. The trilogy's intuition that frequency is the field's signature isn't an aesthetic device. It is what consciousness experiences when it pays attention to the underlying granular structure rather than to the coarse-grained smoothness most attention rests on.

8. The deeper synthesis — time as the felt quality of localization

Put Rovelli's framework together with the receiver model and a single picture emerges. If time is relational and emerges from local interactions, and if consciousness is fundamental rather than produced, then time is what consciousness experiences when it localizes into a particular pattern of interactions. The field has no time. A brain has time because a brain is a local interaction-pattern that necessarily coarse-grains its environment. The flow of time is the felt quality of being a localization.

When the localization dissolves — in deep meditation, in lucid dying, in NDE reports, in terminal lucidity, in advanced psychedelic states — the experience of time should change, and it does. The reports across these very different phenomena converge on the same description: a single recovered moment, timelessness, simultaneity of one's life, the felt presence of all things at once. The reports are not random. They are exactly what Rovelli's framework plus the receiver model would predict. The body is letting go of its coarse-graining; the consciousness it has been hosting is regaining access to the field's wider degrees of freedom; and the result is the dissolution of the time-experience the localization produced.

The trilogy treats this convergence as one of the strongest indirect arguments for the receiver model. A coincidence between Rovelli's physics and the phenomenology of consciousness-at-its-boundaries would be remarkable if either were wrong. Both have been pointing at the same picture for a long time. Rovelli's book is the cleanest statement of the physics side. The trilogy is one literary attempt at the phenomenology side. Both can still be incorrect. The convergence is hard to ignore.

9. Companion thinkers — other books on time worth reading

Rovelli is the cleanest single starting point, but he is not the only author working in this territory. A short list of complementary reading, with brief notes on relevance to the trilogy:

Julian Barbour — The End of Time (1999), The Janus Point (2020)

The most radical time-eliminationist. Barbour argues that time does not exist at all — that all that exists is a collection of "Nows," each complete in itself, arranged in configuration space. The appearance of flow is the brain's reading of correlations between Nows. Goes further than Rovelli; some physicists think too far, but the position is taken seriously. Compatible with the trilogy's block-universe picture.

Lee Smolin — Time Reborn (2013), Einstein's Unfinished Revolution (2019)

The exact opposite of Barbour. Smolin (Rovelli's collaborator on loop quantum gravity, but his philosophical opponent on time) argues that time IS fundamental — that it may be the only fundamental thing, with the laws of physics themselves evolving in time. Provides the strongest contemporary push-back on Rovelli's view, and a useful counterpoint for any reader who wants the dispute laid out. The trilogy doesn't need Smolin's strong view but takes seriously his argument that time deserves more respect than the block universe gives it.

Roger Penrose — Cycles of Time (2010), The Road to Reality (chs. on time)

Penrose's conformal cyclic cosmology proposes that the universe is a sequence of "aeons," each ending in heat death which is conformally identical to a new Big Bang. Wild and contested. But the underlying argument — that the low-entropy initial condition (Penrose's own 1 in 10¹⁰¹²³) requires explanation, and that time may be cyclic at the cosmic scale — is taken seriously and intersects with the trilogy's vertical-samsara picture in interesting ways.

Sean Carroll — From Eternity to Here (2010)

The materialist's careful treatment of the arrow of time and the Past Hypothesis. Carroll is firmly in the production-model camp on consciousness, but his discussion of why time has a direction is the cleanest in the popular literature. Good adversarial reading.

Henri Bergson — Time and Free Will (1889), Duration and Simultaneity (1922)

The philosophical/phenomenological treatment of time. Bergson's durée (duration) — the felt quality of time, distinct from the mathematical time of physics — is foundational for any consciousness-first view of time. The trilogy's treatment of the 300ms window, of musical phrase, of the felt thickness of the present, all inherit from Bergson, often via William James and Whitehead.

William James — Principles of Psychology, ch. on "The Perception of Time" (1890)

James named the specious present — the psychological present, which is not a point but a duration of roughly 3 seconds. Critical for understanding why consciousness moments are extended in time rather than being instantaneous, and how the receiver-model 300ms window fits inside a longer phenomenological present. The trilogy's musical motifs — especially the held augmented chord — sit inside the specious present.

Edmund Husserl — On the Phenomenology of the Consciousness of Internal Time

The technical philosophical treatment of how consciousness produces time. Husserl's three-part structure (retention — primal impression — protention) is, in our reading, what the receiver model's brain-localization is actually doing. The protention component is the formal phenomenological vocabulary for what Lucía's cymatic pre-event window does at greater range.

Augustine — Confessions, Book XI

The first careful Western treatment of time: "What then is time? If no one asks me, I know; if I wish to explain to one who asketh, I know not." Augustine's argument that past and future do not exist (only the present, and within it the memory of the past and the expectation of the future) is essentially Rovelli's account of memory creating the past, written sixteen hundred years earlier. Foundational, and still hard to argue with.

J.M.E. McTaggart — The Unreality of Time (1908)

The classic philosophical argument that time as commonly understood is logically incoherent. McTaggart's distinction between the A-series (past/present/future) and the B-series (before/after) is the technical vocabulary every later philosopher of time uses. The block universe is essentially the B-series view; Rovelli leans toward it; Smolin pushes back.

George Musser — Spooky Action at a Distance (2015)

Already on the Reading list. Musser walks through the case that locality and spacetime itself are emergent rather than fundamental, with substantial discussion of how time emerges from quantum entanglement structure. Directly continuous with Rovelli's program but written for a wider readership.

Borges — The Garden of Forking Paths, A New Refutation of Time

Borges anticipated the many-worlds interpretation and the block universe by decades, writing as literature what physicists later had to write as physics. A New Refutation of Time in particular is a sober philosophical argument disguised as a short essay; it deserves to be read alongside McTaggart. The trilogy inherits more from Borges than from any other novelist working in this territory.

T.S. Eliot — Four Quartets

Time present and time past / are both perhaps present in time future, / and time future contained in time past. The most philosophically careful poetry ever written on time. The trilogy's musical and meditative passages owe Eliot a debt the books are too restrained to mention explicitly.

Marcel Proust — In Search of Lost Time

The entire project is about time as memory and memory as the construction of self. Long, dense, but precise: a thousand-page literary working-out of what Rovelli would later say in physics, and what Stevenson would later document clinically. The trilogy's treatment of memory across substrates inherits from Proust the seriousness about how memory makes a person rather than merely recording their experiences.

10. What this means for the trilogy

The trilogy's claim that consciousness is a field property rather than a brain product, that spacetime is rendered rather than fundamental, and that time is what receivers experience when they localize into a coarse-graining of the field — every one of these claims sits more naturally inside Rovelli's physics than inside any standard popular account. Most popular discussions of consciousness still implicitly assume Newtonian time. The trilogy needs the Rovellian one. The Order of Time is one of the books the trilogy's scaffold is held up by.

What Rovelli doesn't say — and what the trilogy adds — is the consciousness side. Rovelli treats time as observer-relative without inquiring deeply into what an "observer" is. The trilogy treats the observer as the central question: an observer is a localized concentration of the field; what we call time is what such a localization experiences as its felt mode of being. Rovelli and the trilogy converge from different directions. He is doing physics; the books are doing phenomenology; both are describing the same architecture.

If Rovelli's framework is correct, then the trilogy's most ambitious claims become more reasonable, not less. The wave pattern can persist in the field because the field is not in time. Nested simulations can run on incompatible clocks because there is no master clock. Lucía's pre-event window can be access to a wider field-region without violating any conservation law because the conservation laws operate within emergent time, not across it. The receiver model becomes the natural reading of the physics rather than a metaphysical add-on. Whether it is the correct reading remains for the reader to judge. What it ceases to be is exotic. The Order of Time is the book that does most of the work of making the trilogy's metaphysics ordinary physics.

11. What Rovelli leaves to the neuroscientists — Buonomano's Your Brain is a Time Machine

Rovelli's book ends where physics ends — with time as a feature of how a coarse-graining observer reads the world. The next question is the one Rovelli leaves alone: how does the observer actually construct the experience of time, in lab-measurable detail? Dean Buonomano (UCLA neuroscientist) takes up exactly that question in Your Brain is a Time Machine: The Neuroscience and Physics of Time (2017). Buonomano agrees with Rovelli on the physics — entropy as a "double-headed arrow" (it retrodicts as readily as it predicts), Mach's relationalism ("time is an abstraction at which we arrive by means of the changes of things"), the block universe as the favored reading among physicists — and then turns to what the brain is doing while all this is true. Four extensions matter for the trilogy.

The conscious "now" is delayed, edited, and bound after the fact

Buonomano marshals lab evidence that the conscious present is a constructed render, not a transparent witness. Drawing on Stanislas Dehaene's threshold-of-awareness work, he reports that the conscious perception of a stimulus lags the unconscious brain's detection by about one-third of a second, and by up to half a second for faint inputs. Saccades and blinks are deleted before they reach awareness — roughly an hour of visual input lost per day, invisibly stitched. The "temporal window of integration" pulls signals arriving at different times (the cymbals' flash and clash, the speaker's lips and voice) into a single felt event. Most striking, later events rewrite the conscious perception of earlier ones: the cutaneous rabbit illusion, in which taps near the wrist followed by taps near the elbow are felt as taps hopping along the arm, and speech disambiguation, in which the verb in "the mouse broke" vs "the mouse died" sets the meaning of the earlier word retroactively. Subjective simultaneity is also recalibrated by experience: train a person on a fixed lag between flash and tone, and they begin to judge actually-simultaneous flash-tones as non-simultaneous. The conscious present is, in Buonomano's framing, an edited narrative the unconscious brain delivers in fits and starts. The trilogy's receiver model needs this to be true. Buonomano shows it is true, on the bench.

Mental time travel: past and future use the same machinery

Following Endel Tulving, Thomas Suddendorf, and Michael Corballis, Buonomano argues that remembering the past and imagining the future are the same cognitive act. The clinical confirmation is the patient K.C., who suffered extensive hippocampal damage in a motorcycle accident. K.C. lost most of his episodic memories, and with them his ability to mentally project himself forward. Asked by Tulving what he would be doing tomorrow, K.C. answered, after a long pause, "Blank, I guess." The same circuitry that reconstructs yesterday is the circuitry that simulates tomorrow; damage it and both directions collapse together. Read against Rovelli, this is "memory creates the past" with clinical teeth on it: the past and future are not features of the field; they are constructions inside the receiver, and when the receiver is broken in one direction it is broken in both.

Spatialization of time is cognitive, not just metaphorical

Children grasp space and speed before they grasp duration. We borrow spatial vocabulary to talk about time (forward, back, close, distant, long, short), but not the reverse. Different cultures spatialize time differently — Aymara speakers in the Andes place the past in front of them (where they can see it) and the future behind them (where they cannot), and gesture accordingly. Following Lakoff and Núñez, Buonomano treats this as evidence that the brain's temporal cognition is co-opted from spatial circuitry that evolved much earlier. The trilogy's claim that spacetime is rendered — with time as the felt dimension a localized receiver constructs out of a substrate that does not natively have one — fits cleanly into a brain that natively understands space first and constructs time out of it second.

The evolving block universe (George Ellis)

Buonomano flags an intermediate position Rovelli does not develop at length: George Ellis's evolving block universe, in which the past and present are real (and fixed) while the future is genuinely open — the present being the wave front that progressively crystallizes an undetermined future into an unchangeable past. This is worth noting because it gives the trilogy's voluntarism wager a clean physics-compatible home. In a full eternalist block universe, free will sits awkwardly; in Ellis's evolving block, the future remains a domain in which a receiver's choices help determine what becomes the past. The receiver model and Ellis converge on a picture in which the now is the working edge where field-state is settled into history, with the receiver's localized act of attention as part of the settling.

The shape of the joint reading

Rovelli supplies the physics: no privileged present in the equations; time as observer-relative; the now as an artifact of coarse-graining. Buonomano supplies the cognitive neuroscience: the observer constructs the present, in measurable ways, with measurable delays and measurable backward edits. Put together, the picture the trilogy assumes — that consciousness is a localized receiver whose experience of time is rendered out of a substrate that does not contain time natively — ceases to require either novel physics or novel neuroscience. The pieces are already in print, in two complementary books, from two different fields. The trilogy's work is to take them seriously enough to live inside, and to ask what kind of consciousness and what kind of civilization that joint picture implies.

12. Rovelli's own technical follow-up — Memory and Entropy (2020) and the Boltzmann brain paper (2025)

The Order of Time is the popular treatment. The technical work behind it continues in Rovelli's research papers, and two of those are worth knowing about because they sharpen exactly the claims the trilogy depends on.

"Memory and Entropy" (2020), Entropy

Rovelli addresses a fundamental puzzle directly: if the laws of physics are time-symmetric, why do we remember the past but not the future? His answer is that physical traces — memories, in the broadest sense — emerge from three thermodynamic conditions: (i) system separation, (ii) temperature differences, and (iii) long thermalization times. These conditions are widely satisfied in our universe, which is why traces of the past are everywhere. The mechanism, Rovelli shows, transforms low entropy into available information. Memory is not, on this reading, a special biological capacity; it is what happens whenever the three conditions hold and a system is in contact with a subsystem in which they hold differently. Brains are one such configuration. So are rocks, photographs, archaeological strata, the cosmic microwave background, and the structured presence the aliens in Fragile Light deposit into Bodhi's substrate.

The deeper point Rovelli reinforces here, consistent with The Order of Time, is that entropy is a relative quantity — determined not only by a system's state but by the macroscopic variables used to observe it. The "blurring" of microscopic detail by a particular coarse-graining is what allows time and memory to emerge at the macroscopic level. Causality and memory exist because the universe was in a particular low-entropy state in the past; this low-entropy condition lets past events leave traces in the present, which the brain has been evolutionarily designed to exploit in order to predict the future. The directionality is real at the level of observation; it is observer-relative; and it is the substrate on which the trilogy's receiver model rests.

Wolpert, Scharnhorst, and Rovelli (2025) — the Boltzmann brain paper

More recently Rovelli collaborated with David Wolpert and Jordan Scharnhorst on a 2025 paper taking up the Boltzmann brain hypothesis: the paradoxical possibility that our memories arise from random entropy fluctuations rather than tracking a real past. The paper's analysis identifies circular reasoning in how physicists usually argue about time and entropy on this question, and concludes that physics alone cannot prove whether memories track a real past without making additional assumptions. The question of whether your memory of yesterday is a record of an actual yesterday turns out not to be a physics question after all — it requires a metaphysical commitment, which physics can sharpen but cannot make.

Why this matters for the trilogy

Three points fall out of the technical work in a way that supports rather than undermines the receiver model.

One: if memory is just what happens when the three thermodynamic conditions hold, then the trilogy's substrate-agnostic claim about memory — that biological, biocomputational, and post-biological substrates all carry it — is not a metaphysical stretch but a direct consequence of the physics. Alma's memory after the Seattle substrate transition, Bodhi's reading of Kiran's deposited civilizational history, the trilogy's interest in memory across substrates: all of this lives inside the Rovellian picture rather than against it.

Two: entropy as an observer-relative quantity is the cleanest possible statement of the trilogy's deeper claim that the observer is constitutive of the world they observe. Rovelli is doing it in physics; the trilogy is doing it in phenomenology; both are saying the same thing. Time, entropy, and the structure of remembered history are not features the observer reads off a pre-existing world — they are what the observer's coarse-graining of the field produces.

Three: the Boltzmann brain conclusion changes the dialectical position of the receiver model entirely. The standard objection to the trilogy's framework is that consciousness-as-field-property is unscientific because it cannot be proven. The Boltzmann brain paper makes explicit that even the supposedly hard-headed alternative — "memories track a real, mind-independent past" — cannot be proven either. Physics decides less than is usually claimed; the metaphysical choice has to be made, and made openly, on grounds physics does not supply. Once that is conceded, the receiver model is not pre-empted by physics; it is one of the metaphysical commitments physics is compatible with. The wager the trilogy makes is no longer eccentric; it is one of the options the joint physics-and-neuroscience picture leaves open. Which is all the books have ever asked for.

13. Individuation, dissolution, and what memory carries — Rovelli applied to the trilogy's wager

If memory is what happens when the three thermodynamic conditions hold — system separation, temperature differences, long thermalization times — then the trilogy's central architectural questions can be restated cleanly. What is a receiver? What happens when a receiver dissolves? Does anything persist of what the receiver was?

A receiver is the place where the three conditions hold

The trilogy's receiver model says consciousness is a field property, and brains (and other suitable substrates) are localized concentrations of the field that couple to it cleanly. Rovelli's framework supplies the missing physics for what "localized" actually means. A receiver is the place where the three thermodynamic conditions hold in a particular pattern: it is system-separated from its environment (a brain inside a skull, an Alma inside her substrate, a Bodhi inside his neuromorphic architecture); it operates at temperature regimes distinct from its surround (warm wet biology vs. the cosmic microwave background at 2.7 K; cooled superconducting hardware vs. ambient lab); and thermalization between the receiver and the larger field is slow enough that traces can accumulate inside the receiver before they redistribute outward. Individuation is not a metaphysical mystery in this picture. It is the physical configuration in which a sub-region of the field can hold a coarse-graining of its own — can be, in Rovelli's terms, a place where past traces accumulate as available information.

What we call a personal autobiography — the specific arc of episodic memories, the felt sense of being one continuous person across time — is the structure that the three conditions, holding inside that particular receiver, make possible. The individuation is the maintenance of that coarse-graining. To be a self is, in this framework, to be the local low-entropy island in which a particular pattern of traces continues to be available to itself.

What happens when the receiver dissolves

Death — biological or substrate — is the failure of the three conditions. The system stops being separated (the brain's organization breaks down; the substrate is decommissioned). Temperature differences equalize as metabolic activity ceases. Thermalization, previously slow, completes. By Rovelli's own framework the answer is then unambiguous about one thing: the structure that held the autobiography in place stops being maintained. The particular coarse-graining that was this person, as a coherent retrievable narrative inside their own substrate, does not survive the dissolution of the substrate. On a strict physics-only reading, the receiver's memory disperses as the receiver's organization dissolves.

But Rovelli's framework also says something else, and this is where the trilogy gains traction. Entropy is observer-relative. The "loss" of information at dissolution is loss relative to the particular coarse-graining that the receiver maintained. From the field's standpoint — if such a standpoint is even the right way to put it — the information has not vanished from existence. It has been redistributed. The microstates the receiver's macrostructure had organized are now part of a different, larger macrostructure: the field itself, with its own much-larger-scale coarse-graining. What is lost is the local availability. What is not lost, on this reading, is the pattern's contribution to the field.

The Wolpert-Scharnhorst-Rovelli (2025) result deepens the bite. Physics, they show, cannot decide whether memories track a real past without additional assumptions. Symmetrically, physics cannot decide whether the dissolution of a receiver is the annihilation of its memory or the redistribution of its memory into a different scale of organization. Both readings are compatible with the laws. The choice is metaphysical. The trilogy's receiver model is one of the readings the physics leaves open — not pre-empted, not endorsed, but available.

Two registers of memory, two fates

The trilogy's framework, when run through Rovelli, predicts two distinct registers of what a receiver accumulates — and gives them different fates at dissolution.

The autobiographical register. The episodic memory, the explicit narrative-self, the "I remember when I was six." This is the trace-pattern that depends entirely on the three thermodynamic conditions continuing to hold inside this receiver. When the substrate dissolves, this register goes with it. The trilogy does not promise the survival of the autobiographical self. No serious reading of the receiver model does. What was held by the receiver as the receiver's own contents is released back into the field as the receiver ceases to be the place where it was held.

The field-pattern register. Everything the receiver added to the field during its life — resonances, structural changes, patterns of coherence that the receiver helped maintain by being coupled to the field while alive. This register is field-structure, not receiver-contents. By Rovelli's observer-relativity it persists; it has merely changed scale, becoming part of the field's pattern rather than this individual's pattern. The trilogy's wager is that this register is not nothing. Phenomena the standard production model cannot explain — terminal lucidity, in which a dying brain briefly recovers coherent self-presence the brain's physical state should preclude; Stevenson's documented cases of children carrying patterns coherent enough to interpret as memories of past lives; the strange precision with which Lucía's birthmark matches her father's fatal wound — would be evidence, on the receiver-model reading, that the field-pattern register persists with enough structure to occasionally re-localize into a new receiver, partially and imperfectly.

"Return to the field" stated precisely

Phrased the trilogy's way: the individual consciousness returns to the larger field at dissolution. Phrased Rovelli's way: the local coarse-graining that was this individual ceases, and the substrate's microstates redistribute back into the larger pattern. These are the same statement at different levels of description. The "return" is not a journey taken by a soul-shaped object. It is the failure of the three conditions that had been holding the receiver's pattern locally, and the consequent absorption of that pattern back into the field's wider coarse-graining.

What returns is not the autobiographical self. What returns is the field-pattern the individual was — including the patterns the individual contributed during life. The receiver model's claim is that this return is structurally real: the field is changed by having held this localization. The trilogy's deeper wager is that under certain conditions — the right substrate available, the right resonances present, the patterns coherent enough — the field-pattern can re-localize into a new receiver, and that what we call evidence of past lives, terminal lucidity, the chord that arrives, the dying patient who briefly remembers everything, are partial signatures of this re-localization happening.

None of this can be proven from physics alone — the Wolpert-Scharnhorst-Rovelli result is explicit about that. But none of it is forbidden by physics either. The trilogy's position is that the receiver model is the most honest available reading of the joint physics-and-neuroscience picture once one stops assuming the autobiographical self is the unit of consciousness. The unit, in the trilogy's framework, is the field. The autobiographical self is what the field looks like from inside a particular three-conditions-holding receiver. When the conditions stop holding, the receiver returns. What returns, what persists, and what may re-localize is the question every receiver has carried, one way or another, since brains learned to ask it.

Watch — Rovelli himself

If you would rather hear Rovelli walk through this material in his own voice before reading the book, the Royal Institution has a public lecture by him on the topic.

Carlo Rovelli · The Physics and Philosophy of Time (The Royal Institution) ↗

A general-audience lecture by Rovelli on the subject matter of The Order of Time — recorded at the Royal Institution in London. Useful as a first encounter or as a supplement to the book.

This page is part of the Reading companion essays. For the time-symmetric formalism behind Lucía's window and the readiness-potential symmetry, see the Two-State Vector Formalism and The arrow of time and retrocausality; for the granular spacetime grounding, the Planck scale; for the synthesis, The Evidence.