These are lectures notes prepared for a series of seminars I am invited to give at Princeton Philosophy Department in November 2024. They cover the conceptual structure of quantum gravity, the relational interpretation of quantum mechanics, the structure of time, its orientation and the openness of the future, the physical underpinning of information and meaning, and some general considerations on the fact that concepts evolve, on perspectivalism and anti-foundationalism.
These are lectures notes prepared for a series of seminars I am invited to give at Princeton Philosophy Department in November 2024. They cover the conceptual structure of quantum gravity, the relational interpretation of quantum mechanics, the structure of time, its orientation and the openness of the future, the physical underpinning of information and meaning, and some general considerations on the fact that concepts evolve, on perspectivalism and anti-foundationalism.
It has been 61 years since Hugh Everett III's PhD dissertation, {\it On the Foundations of Quantum Mechanics}, was submitted to the Princeton University Physics Department. After more than a decade of relative obscurity it was resurrected by Bryce DeWitt as {\it The Many Worlds Interpretation of Quantum Mechanics} and since then has become an active topic of discussion, reinterpretation, and modification, especially among philosophers of science, quantum cosmologists, and advocates of quantum decoherence and quantum computing. Many of these analyses are quite sophisticated and considered to be important contributions to physics and philosophy. I am primarily an experimental physicist and my pragmatic ruminations on the subject might viewed with some suspicion. Indeed, Bohr's pragmatic {\it Copenhagen Interpretation} is often disparaged by this same cohort. Still, I think that my experimentalist's vantage point has something to offer and I here offer it to you.
CosmoBeating • Causal Ledger (CB•CL) A Ledger Reading of Time: Why Physics Never Settled What Time Is A short, non-technical companion to the five-paper CosmoBeating: Causal Ledger (CB•CL) series, written for readers in physics, philosophy of science, or quantum foundations — not requiring familiarity with the author's wider theoretical framework. The core idea, stated plainly Physics has never agreed on whether time is a thing that exists on its own, or merely the readout of something more basic. This series argues for the second option. Time is treated here not as a stage on which events happen, but as the readout of accumulating causal relations — a ledger. The past is the set of entries already settled. The future is the next entry, projected from settled entries according to fixed rules. The present is the entry currently being written. Nothing here claims to overturn general relativity or quantum mechanics; the claim is narrower: recasting time this way dissolves several long-standing puzzles without adding new physics. Four battles physics has never won The series opens by surveying four genuinely unresolved disputes sharing one hidden root. Quantum gravity's "frozen formalism problem," where the whole-universe wavefunction shows no time evolution at all. The century-old split between presentism and eternalism over whether past and future are equally real. The tunnelling-time debate, where different experiments disagree on whether tunnelling takes zero time or a measurable delay, because physicists have never agreed on what should count as the clock. And relational quantum mechanics' own self-reference problem: if every fact is relative to some observer, relative to whom is that statement itself true? The series treats these as four disguises of one question, not four separate defects. A refresh rate that never changes, and a synchronisation rate that always does The series proposes two variables: a refresh rate, fixed at the speed of light, describing how fast any ledger accumulates its own entries — a property of the pen, not the paper; and a synchronisation rate, describing how efficiently two different ledgers can be compared, which does change — reduced by a medium (slow-light and stopped-light experiments) and by gravity (the Shapiro delay, redshift near a black hole horizon). Both effects are real, independently published physics; the series proposes only that they be read as two separate, never-merged solutions to one synchronisation term, not as evidence that time itself slows down. Three thought experiments, checked against real physics A runner approaching a companion is reread as a change in constraint conditions, not a future conjured from nothing. Two observers, one on Earth and one falling toward a black hole horizon, see distorted, delayed images of each other — not because either clock misbehaves, but because the delivery route of light is not the ledger itself. A single particle that has never interacted with anything else is shown to have never entered the category of "having a past" at all, built to run parallel to relational quantum mechanics. Each experiment is checked against the standard resolution of the twin paradox, the optics of the Schwarzschild horizon, and Rovelli's own writing on relational facts. Where the series draws its own line The final paper does not extend the theory further; it marks where it stops. It names the requirement that a story's narrator must remain distinct from its protagonist, shows this is structurally the same difficulty relational quantum mechanics has never solved, and states plainly which of its own claims are borrowed physics, which are original proposal, and which are narrative language for readability — plus the specific findings that would force each claim to be withdrawn. What the full series covers Paper 0 surveys the four unresolved battlegrounds. Paper I sets out the ledger axioms and redefines past, present, and future. Paper II solves the synchronisation rate along its two separate axes. Paper III runs the three thought experiments and extends the reasoning, cautiously, to photosynthesis and bird magnetoreception. Paper IV closes the series with falsifiability grading and open questions. A note on method Every paper separates established physics from original proposal from narrative language, and closes with the specific result that would falsify its claim. Readers are encouraged to treat every theoretical claim here as a testable hypothesis, not settled fact. Keywords: philosophy of time, quantum gravity, relational quantum mechanics, Schwarzschild horizon, twin paradox, tunnelling time, falsifiability, information theory, quantum biology, CosmoBeating AuthorWai-Hung Tam (Pan), Independent ResearcherORCID: 0009-0002-7789-8464Email: panxtam@protonmail.com
CosmoBeating • Causal Ledger (CB•CL) A Ledger Reading of Time: Why Physics Never Settled What Time Is A short, non-technical companion to the five-paper CosmoBeating: Causal Ledger (CB•CL) series, written for readers in physics, philosophy of science, or quantum foundations — not requiring familiarity with the author's wider theoretical framework. The core idea, stated plainly Physics has never agreed on whether time is a thing that exists on its own, or merely the readout of something more basic. This series argues for the second option. Time is treated here not as a stage on which events happen, but as the readout of accumulating causal relations — a ledger. The past is the set of entries already settled. The future is the next entry, projected from settled entries according to fixed rules. The present is the entry currently being written. Nothing here claims to overturn general relativity or quantum mechanics; the claim is narrower: recasting time this way dissolves several long-standing puzzles without adding new physics. Four battles physics has never won The series opens by surveying four genuinely unresolved disputes sharing one hidden root. Quantum gravity's "frozen formalism problem," where the whole-universe wavefunction shows no time evolution at all. The century-old split between presentism and eternalism over whether past and future are equally real. The tunnelling-time debate, where different experiments disagree on whether tunnelling takes zero time or a measurable delay, because physicists have never agreed on what should count as the clock. And relational quantum mechanics' own self-reference problem: if every fact is relative to some observer, relative to whom is that statement itself true? The series treats these as four disguises of one question, not four separate defects. A refresh rate that never changes, and a synchronisation rate that always does The series proposes two variables: a refresh rate, fixed at the speed of light, describing how fast any ledger accumulates its own entries — a property of the pen, not the paper; and a synchronisation rate, describing how efficiently two different ledgers can be compared, which does change — reduced by a medium (slow-light and stopped-light experiments) and by gravity (the Shapiro delay, redshift near a black hole horizon). Both effects are real, independently published physics; the series proposes only that they be read as two separate, never-merged solutions to one synchronisation term, not as evidence that time itself slows down. Three thought experiments, checked against real physics A runner approaching a companion is reread as a change in constraint conditions, not a future conjured from nothing. Two observers, one on Earth and one falling toward a black hole horizon, see distorted, delayed images of each other — not because either clock misbehaves, but because the delivery route of light is not the ledger itself. A single particle that has never interacted with anything else is shown to have never entered the category of "having a past" at all, built to run parallel to relational quantum mechanics. Each experiment is checked against the standard resolution of the twin paradox, the optics of the Schwarzschild horizon, and Rovelli's own writing on relational facts. Where the series draws its own line The final paper does not extend the theory further; it marks where it stops. It names the requirement that a story's narrator must remain distinct from its protagonist, shows this is structurally the same difficulty relational quantum mechanics has never solved, and states plainly which of its own claims are borrowed physics, which are original proposal, and which are narrative language for readability — plus the specific findings that would force each claim to be withdrawn. What the full series covers Paper 0 surveys the four unresolved battlegrounds. Paper I sets out the ledger axioms and redefines past, present, and future. Paper II solves the synchronisation rate along its two separate axes. Paper III runs the three thought experiments and extends the reasoning, cautiously, to photosynthesis and bird magnetoreception. Paper IV closes the series with falsifiability grading and open questions. A note on method Every paper separates established physics from original proposal from narrative language, and closes with the specific result that would falsify its claim. Readers are encouraged to treat every theoretical claim here as a testable hypothesis, not settled fact. Keywords: philosophy of time, quantum gravity, relational quantum mechanics, Schwarzschild horizon, twin paradox, tunnelling time, falsifiability, information theory, quantum biology, CosmoBeating AuthorWai-Hung Tam (Pan), Independent ResearcherORCID: 0009-0002-7789-8464Email: panxtam@protonmail.com