It is bold to speak of new physical theories; there are far too many that we will never hear about again, and one must admit that the January paper “Three‑Dimensional Time: A Mathematical Framework for Fundamental Physics” seems a little too audacious. It not only postulates three dimensions of time—which is already hard to swallow—but also that the three spatial dimensions and even particles themselves are produced by the interaction of these three differentiated forms of physical temporality. This idea is not entirely new, since there were already reasons to think that the time parameter t should have three components t_x, t_y, t_z (with t² = t_x² + t_y² + t_z²). Here the proposal is different, but no less surreal and difficult to imagine. The article was published in a minor yet peer‑reviewed journal (Reports in Advances of Physical Sciences). So far, there is no substantive critique of this latest attempt to unify physics on entirely new grounds. The mathematical framework has the attraction of preserving causality and claims to predict the properties of the different generations of particles as well as reproduce their masses. All this remains to be verified.
Without in any way claiming to judge its validity, what interests me is that this theory echoes, in a certain way, the tripartition I stressed in a 2021 text (“Quantum Determinism, Entropy and Freedom”) between quantum, classical and cosmological physics, which do not obey the same laws and differ above all by their distinct temporal ranges. Even if I’m not truly convinced, its interest lies in identifying reality with time itself, like Lee Smolin—and unlike almost everyone else, who treats time as a pre‑given illusion (a block universe). The theory at least has great power to disorient, reopening the question of temporality, its origin and its irreversibility, and giving me the opportunity to revisit the place accorded to entropy, improbability and the arrow of time.
The Three Times: Dynamics of the Universe
The model distinguishes three dimensions of time. Time is not a single axis but a structure with three independent dimensions—though they seem to nest together—differentiated by physical scale and function:
- Quantum time – At the Planck scale it produces the fundamental constants and the three generations of particles, as well as their masses, via the three eigen‑states of the resonant structure of this temporal field. It operates in the regime of fluctuations, resonance and indeterminacy. Its non‑deterministic behavior, dominated by fluctuations, constitutes the dynamic basis of reality.
- Classical time – This is local time, the time of measurements and events. It carries causality and our human perception of the succession of events (yet is itself assumed to contain no intrinsic arrow, being reversible!).
- Cosmological time – A very slow but irreversible directional time on the scale of the universe—bearer of cosmic and gravitational structure. It regulates expansion, curvature and the global conditions of cosmic evolution. Gravity—and more generally the gravitational curvature of general relativity—would result from the dynamics of cosmological time, geometrically unifying gravity and cosmology with particle physics. This would not be the time of causality but of the shape of space‑time, of the evolution of the universe—a geometric constraint, not a chain of events. More surprising (but just as in the Standard Model), it would nonetheless be the origin of the growth of entropy: its asymmetry would make possible the irreversibility observed in classical time and would constitute the arrow of time.
The article proposes that three‑dimensional space does not exist at a fundamental level but is born through a mathematical transformation of two temporal dimensions. A symmetry‑breaking among these three initially equivalent temporalities would produce a global metric that articulates them within a common mathematical space. This metric field would then give rise to three spatial degrees of freedom—in other words, three‑dimensional space emerges. Space is no longer a primary datum but a structure derived from temporal complexity, a mathematical residue of these three times. Conventional notions of space and time thus become emergent phenomena from a more fundamental level.
Discussion
I am by no means sure that my understanding (aided by ChatGPT) is adequate, but my real subject is not to assess the theory’s validity; rather, it is to explore the questions raised by reducing physics to temporality. If distinguishing different temporalities deserves attention, the emergence of space is far more enigmatic. But this attempt to ground physics in time is chiefly an opportunity to challenge prevailing assumptions about the direction of time and the origin of entropy—rejecting both the alleged reversibility of time and the idea that the arrow of time stems from the low entropy of the Big Bang, when it should instead be attributed to gravity within a far more dialectical view of entropy.
1 • Irreversibility and the Arrow of Time
Mathematically, a time axis has no arrow: it is symmetrical (as in classical mechanics or Schrödinger’s equation). Classical laws (like Newtonian mechanics or even general relativity, locally) are assumed to be reversible. In the article, there is an ambiguity about the origin of the arrow of time, first attributed solely to cosmological time and later presented as an emergent phenomenon from the interaction of the three times. More precisely, the arrow of time results from a global irreversibility, induced by cosmological asymmetry, structured by quantum dynamics, and manifested locally in classical time.
The arrow of time is therefore the combined effect of:
- Quantum indeterminacy (decoherence, wave‑function collapse) introducing irreducible fluctuations at the Planck scale—yet not an arrow of time in itself;
- Classical causality (which is nonetheless treated as reversible);
- Cosmological asymmetry (increasing entropy and cosmic expansion). The universe evolves from an extremely dense, hot state (Big Bang) toward a cold, diffuse, dilated one. This evolution gives a macroscopic direction to time: from low to high entropy. To escape reversibility, the thermodynamic arrow of time must rest on the universe’s initial asymmetry—that is, on the structure of cosmological time.
In other words, what we experience as an irreversible succession is not an immediate given but a local projection of a broader temporal structure. It seems odd that thermodynamics, omnipresent at our scale, could depend on a global cause; yet the most confusing (though widely accepted) idea is that quantum and classical times might be reversible, needing cosmological time to orient the arrow. One might instead expect that symmetry‑breaking would give a privileged direction to classical time, the time of causal sequences.
At our scale we clearly observe irreversibility: heat spreads, gases mix, organisms age, and entropy increases. It is hard to understand how this real irreversibility (a broken egg, dissipated heat, biological death) could depend on a global entropy increase fully determined by the universe’s very particular initial conditions. Refusing to attribute the arrow of time to classical causality and local heat gradients is pure dogmatic deduction.
To reconcile everything, one would need to accept simultaneously that:
- Physical laws are reversible;
- Entropy growth stems from the universe’s very low‑entropy beginning; and
- Entropy depends not on local laws but on cosmological time.
But physical equations would be reversible only if they were perfectly complete—lacking chaotic indeterminacies, non‑linear phenomena or external perturbations. Reversing time itself (inverting all velocities) is another matter and a mathematical illusion beloved of sci‑fi. Measurement and interaction always introduce irreversibility. The real arrow of time is that of causal order (the expanding light cone), of which entropy increase is an integral part.
2 • The Initial‑Entropy Problem
The mainstream view holds that the universe began in a state of very low entropy—an idea meant to explain the arrow of time and to supply the entropic “capital” spent thereafter. Yet this merely assumes what it must explain. As I wrote elsewhere, “Entropy is one of the most fundamental concepts in physics. It is, however, poorly secured…” Maximum entropy is equally hard to define without contradiction. People cite black holes as objects of maximal entropy, yet the Big Bang—an even more concentrated state—is said to be of minimal entropy. If the universe were cyclic or sprang from a black hole, the maximal entropy of one cycle would have to be the minimal entropy of the next—a contradiction.
We thus posit, but do not explain, an initial low‑entropy state: a young, homogeneous, isotropic, dense yet “ordered” universe, supposedly offering an entropic potential to dissipate. Why should the universe have begun in such an improbable state?
- It begs the question of the origin of order.
- It treats entropy as a primary datum rather than an effect.
- It fails to explain the intricate structures we observe—stars, molecules, biospheres.
Penrose’s view that the Big Bang had minimal entropy (because of very low “gravitational entropy”) seems difficult to accept, given that gravity amplifies differences rather than producing uniformity.
3 • Gravity as Negative‑Entropy Producer
Fashionable theories (e.g., Erik Verlinde, holographic gravity) treat gravity as an emergent effect of entropy. I believe the opposite: gravity makes entropy possible because it produces order. It concentrates matter, generates stars, heavy elements, planetary systems—reservoirs of entropic potential. Gravity is not “negative energy” canceling positive energy; it is negative entropy, the generator of structure and complexity.
Thus:
- Gravity locally opposes dispersion, concentrates and structures matter.
- The resulting structures are reservoirs of potential entropy.
- This capital fuels later entropic cycles—work, dissipation, wear.
- Only thanks to these ordered structures can local entropy increase.
4 • Gravity as a Constructive Arrow of Time
Against the standard “low‑entropy beginning,” one can argue that it is gravity’s production of improbable order that embodies irreversibility. Gravity creates the entropic capital later dissipated at the classical‑thermodynamic level. The universe wasn’t born ordered; it became a source of order through gravity.
5 • Dialectical, Non‑Linear, Non‑Arithmetical Entropy
Entropy precedes gravity but remains formless
Dispersion dominated before atoms formed. For gravity to create low‑entropy concentrations, there first had to be primordial entropy to work with—lighting up Prigogine‑style dissipative structures and biological metabolism.
Gravity gives shape to entropy
Gravity channels that primordial disorder, producing diversified atoms, planets, self‑organisation and biospheres. It orients entropy, granting it tempo and fertility.
The dialectic of entropy
Entropy is not something that simply increases; gravity introduces a dialectic between production and destruction. There coexist thermodynamic entropy and durable anti‑entropic bubbles (living organisms) in an unstable dance.
Entropy is not arithmetical
Unlike energy, entropy is qualitative, viewpoint‑dependent and often incalculable. A small action can have huge consequences, and vice‑versa.
Biological anti‑entropic time
A fourth temporal form—that of living beings—adds information and purpose. Built on classical and quantum time, it is teleological: oriented toward anti‑entropic ends (reproduction) and tested by selection. Life’s resistance to entropy is itself a consequence of entropy, sharing its dialectical nature: life feeds on death, ecological collapses can seed renewal…
Jean Zin, “Les trois dimensions du temps, la gravité et l’entropie”, 28 June 2025
English translation by ChatGPT (OpenAI), licensed CC‑BY‑SA 4.0
(Ce n'est pas une traduction mais plutôt un digest de ChatGPT. Voir la traduction DeepL en pdf plus complète).
