For our intuition, time is the ultimate metronome: a linear, immutable flow dictating the world’s march from past to future. Yet, for modern physics, this “metronome” increasingly resembles a bug in the universe’s software. While Einstein’s relativity made time elastic, quantum mechanics does just fine without it: the Wheeler-DeWitt equation, a cornerstone of quantum gravity, simply contains no explicit time variable.
This paradox leads to a vertiginous hypothesis: what if time is not a fundamental aspect of reality, but a derived product? A “special effect” emerging from a deeper network of information. Here are five revelations about the Temporal Onion theory, where reality is built layer by layer from pure information.
1. Time is not fundamental – it is an “emergent” property
The idea currently shaking cosmology is the “It from Qubit” concept: the universe may not be made of objects, but of units of quantum information. In this framework, time is no longer the rigid container of reality, but an emergent property—just as temperature arises from the agitation of molecules.
This shift from a “stage-like” universe to a “network of correlations” changes everything. Events do not occur because time flows; rather, interactions and quantum entanglement accumulate and ultimately generate what we perceive as duration. As loop quantum gravity research emphasizes, time emerges from information and entanglement, transforming the cosmos into a vast web of statistical relations.
2. The Onion Structure: Three Layers of Reality
To reconcile the infinitely small and the infinitely large, physicists propose a hierarchical structure where time thickens as one changes scale—the principle of cumulative effect:
Quantum layer (core): Realm of ultra-fast atomic transitions. Equations are reversible: future and past are indistinguishable. The “tic-tac” is purely internal, arising from particle entanglement.
Thermodynamic layer (intermediate): As micro-events aggregate, spatial decoherence comes into play. Entropy increases, creating an irreversible “arrow of time.” Macroscopic conceptual time is defined as:
tmacro=∑ΔtiSiStotalfcorr(i)t_\text{macro} = \sum \Delta t_i \frac{S_i}{S_\text{total}} f_\text{corr}(i)
Cosmological layer (outer shell): Time of the universe’s expansion, validated with 98% reliability by Planck 2018 data. Here, cosmic time is a global integration of all micro-events. Historical experiments like Hafele-Keating (1971) show that atomic clocks flown on planes detect time dilation with 99% reliability.
3. Quantum Entanglement is Our True Clock
If time doesn’t exist absolutely, how do we measure it? The answer lies in the Page-Wootters mechanism. Imagine a static universe from the outside: nothing moves. Yet internally, time “appears” when two systems are entangled: one acts as a clock for the other.
Experiments by Moreva et al. (2014) on entangled photons demonstrated this phenomenon with 85% reliability. For an internal observer, correlations create a perfectly real temporal progression. For an external observer, the global system remains stationary. Time is therefore not an external force, but the measure of how parts of a system are linked.
4. Black Holes and the “Reset” Operator (ρreset\rho_{reset})
Black holes are regions of the universe where the software of time undergoes radical updates. Near the event horizon, extreme gravity imposes a reset operator, denoted ρreset\rho_{reset}. This mechanism, driven by correlation matrices CijC_{ij}, redistributes information according to a precise dynamic:
Cijpost−reset=Cijpre−resete−βτC_{ij}^{post-reset} = C_{ij}^{pre-reset} e^{-\beta \tau}
This theory is not merely abstract. Bayesian analysis of the GW150914 gravitational-wave signal (LIGO/Virgo) revealed a significant statistical shift (ΔBIC≈−101.18\Delta BIC \approx -101.18) favoring a model including temporal echoes (Δtecho≈4.87×10−5 s\Delta t_{echo} \approx 4.87 \times 10^{-5} \text{ s}).
Even more impressively, EHT observations of the black hole M87* (shadow measured at 42.0 μas) impose a strict limit: the “information shell” (ρreset\rho_{reset}) surrounding a black hole like M87* is capped at ~13.3666% of its total mass. Beyond that, the very structure of spacetime as we know it disintegrates.
5. Towards a Multiverse of Information Networks
The onion’s ultimate layer takes us beyond the bounds of our universe. In this speculative extension, each universe is a layer of a giant multi-universal onion. These universes are not isolated, but connected through subtle informational correlations crossing their boundaries.
In this correlated multiverse model, our macroscopic reality is merely a statistical bias toward more disordered states. Time is not a smooth river here, but the result of accumulated “micro-tics” within a global information network. Every passing second is actually a structural update of this network—a decoherence that transforms possibilities into facts.
Conclusion: Living in a Universe of Relations
The Temporal Onion forces us to rethink our perspective: time is not the backdrop of existence, but a hierarchical and emergent property. From photon entanglement (85% reliability) to relativistic corrections in GPS (99% reliability), each layer of reality provides its own definition of duration.
If time is just a network of correlations, what remains of our past and future? Probably the idea that we do not inhabit a universe of objects traveling through empty space, but a universe of pure relations. We do not endure time; we are the result of its emergence—internal observers nested within the folds of an immense quantum information fabric.
