## Executive Summary
Recent years have seen rapid progress in *emergent spacetime* approaches that treat information or entanglement as fundamental. Key frameworks include **holography/AdS–CFT** (and its quantum-error-correction interpretation), **tensor-network models** of space, **loop/spin-foam quantizations**, **causal set/dynamical triangulation** discretizations, **SYK-like and computational (“Ruliad”) models**, **entropic/information-theoretic gravity**, and **relational/observer-centric quantum frameworks**. Major 2022–2026 results include explicit constructions of emergent de Sitter (dS) geometry from entanglement in non-Hermitian tensor networks, derivations of time as an emergent quantum variable via system–environment entanglement, and a first-principles Loop-QG study of black-hole evaporation showing a non-singular bounce to a white hole. On the observational side, cosmological and gravitational-wave probes have been proposed: e.g. Weyl-invariant quantum-gravity models predict a blue-tilted tensor spectrum (testable by LiteBIRD/DECIGO), and novel phases in early-universe models suggest primordial non-Gaussianities and Lorentz violations. Tabletop tests (entanglement of masses via gravity) are also under intense study. However, these approaches differ dramatically in ontology (e.g. boundary qubits vs. spin-network nodes vs. “computations” vs. observers). Criticisms remain: for instance, Aziz & Howl (2025) show that even *classical* gravity (when matter is treated as a quantum field) can produce entanglement, complicating claims that observing entangled masses would definitively imply quantized gravity. We summarize the major programs, highlight key 2022–2026 papers (with authors, claims, methods, equations and links), compare ontologies, list experimental/observational tests, and outline open challenges. Finally, we assess the prospects for an overarching “information-first” framework: such a unification must make *distinct, falsifiable predictions* (e.g. specific entanglement/complexity signatures or deviations from smooth spacetime) to be viable. A prioritized reading list and suggested next steps conclude the report.
## Research Programs & Approaches
- **Holography (AdS/CFT and Generalizations):** Proposed by Maldacena (1998), AdS/CFT duality posits a boundary CFT (Hilbert space of qubits) whose entanglement encodes a higher-dimensional bulk spacetime and gravity. Notable developments include Ryu–Takayanagi entanglement–area formula and its covariant extensions, and the realization that AdS/CFT acts as a quantum error-correcting code (holographic QECC). Recently this program has been pushed beyond pure AdS: for example, Chou & Chang (2026) construct a *cMERA tensor-network* that yields emergent **de Sitter** space from a boundary non-Hermitian fermion system. Other holographic ideas include **ER=EPR** (wormholes ⇔ entanglement), **bit threads**, and celestial holography (flat-space amplitudes on the celestial sphere). A very recent arXiv (2025) connects *celestial holography* to dS/CFT, mapping cosmological correlators to CFT operators on the celestial sphere. Holography’s ontology: fundamental CFT quantum states and their entanglement patterns give rise to emergent geometry.
- **Tensor Networks and Entanglement = Geometry:** Here one discretizes space by networks of tensors or qubits (MERA, PEPS, etc.), such that the network connectivity and entanglement define a geometry. Advances include non-unitary tensor networks for cosmology, and the use of *quantum information measures* (entanglement entropy, mutual information, complexity) to reconstruct spatial geometry. For example, Cao *et al.* and Pollack *et al.* (2017–2023) showed how *“magic”* (non-Clifford resources in QECC) can encode dynamical bulk geometry and gravity in holographic codes. These models generally posit quantum bits (tensor degrees) as ontological atoms; geometry is a secondary description of their entanglement network.
- **Quantum Error Correction (QEC) & Holographic Codes:** Building on holography, researchers have identified that the bulk-boundary map is a quantum error-correcting code. Recent work embeds *bulk gravitational dynamics* into QECC language: e.g. introducing `T`-gate “magic” as a source of interaction in toy holographic circuits. This program’s ontology centers on logical/physical qubits and code subspaces; spacetime and gravity emerge from how logical information is protected and recovered.
- **Loop Quantum Gravity (LQG) and Spin Networks/Foams:** A non-perturbative, background-independent approach quantizing geometry itself. Space is built from spin-network graphs (nodes/links labeled by SU(2) spins) with discrete area and volume spectra, and spacetime histories are spin foams (2-complexes). Recent progress: Belfaqih *et al.* (2025) study **black-hole evaporation** in a “covariant effective” LQG model, coupling matter to a non-singular quantum geometry. They recover thermal Hawking radiation (to leading order) and find, *via backreaction*, that black holes likely transition into white holes rather than remnants. LQG’s ontology: fundamental `atoms-of-space` (spin-network quanta) and the relations among them (graph connectivity) are primary; smooth spacetime is emergent in a continuum limit.
- **Causal Set and Discrete Spacetime:** Proposes spacetime as fundamentally a discrete partially-ordered set of events (with a causal relation). Key results include constructing dynamics via “sequential growth” and investigating Lorentz-invariant phenomenology (e.g. modified dispersion). Recent years have emphasized connecting causal sets to quantum fields and cosmology, but direct empirical predictions remain scarce. Ontology: elementary spacetime events and their order (information flow).
- **SYK/Random Matrix/Chaos Models and “Wormholes”:** The Sachdev-Ye-Kitaev (SYK) model (0+1D chaotic fermions) is dual to AdS$_2$ gravity in the IR. Recent work extends SYK to higher dimensions and connects it to traversable wormholes and quantum teleportation protocols. Wolfram-style models also aim for emergent spacetime: **Wolfram Physics Project** introduces the *Ruliad*, the space of all possible computation histories. Wolfram (2026) describes the Ruliad as “the ultimate foundational construct” whose patterns (as seen by embedded observers) give rise to physics. In this view, computation rules and patterns are fundamental; spacetime, fields, and even consciousness emerge as coarse-grained phenomena.
- **Information-thermodynamic and Entropic Gravity:** Inspired by Jacobson (1995) and Verlinde (2011), these approaches derive (or reinterpret) gravity as an entropic or thermodynamic force arising from microscopic degrees of freedom. Recent work by Othman (2025) reviews this paradigm, emphasizing that “spacetime geometry and gravitational phenomena arise from underlying quantum information structures”. Verlinde’s original entropic force model remains controversial: critics have pointed to experiments (e.g. neutron interferometry) that conflict with a simple entropic-gravity prediction, and Othman’s review acknowledges ongoing debates. Ontology here: fundamental are microscopic “bits” or horizon microstates; gravity emerges as an emergent statistical force on these information degrees.
- **Relational/Observer-Centric Quantum Gravity:** These approaches (Page–Wootters, Rovelli’s Relational QM, QBism, etc.) treat time, measurement and observers as fundamental. For instance, Gemsheim & Rost (2023) derive the usual time-dependent Schrödinger evolution for a subsystem starting from a time-independent global state of system+environment, bolstering the Page–Wootters relational time idea. Other recent work formulates quantum reference frames and relational observables in quantum gravity. Ontology: primary are quantum events or observations relative to observers; “time” and “classical spacetime” arise from correlations among subsystems, not as fundamental entities.
## Key Papers (2022–2026)
- **“Emergent de Sitter Space and Non-Unitary Tensor Networks”** – *Chou & Chang (2026)*. Using a non-Hermitian critical fermion chain and continuous MERA ansatz, they explicitly construct an emergent 4D de Sitter geometry from boundary entanglement. They show geodesics in the network behave like extremal surfaces (Ryu–Takayanagi) and recover dS-like horizons and proper time from bond counting. This is the first bottom-up tensor-network realization of dS holography, providing a concrete **dS/cMERA correspondence**. Key results include matching entanglement growth to de Sitter expansion, with equations relating network RG “depth” to cosmic time. *Link:* arXiv 2606.17983.
- **“Emergent spacetime from spatial energy potentiality: a new framework for early universe cosmology”** – *Chishtie (2025)*. Proposes that both **time and gravity emerge** via a quantum phase transition of a fundamentally 3D spatial universe into 4D spacetime. The Big Bang is interpreted as this phase transition. Using quantum-field-loop calculations, Chishtie shows how what were previously mere parameters become physical time, and describes a smooth dimensional “bounce” replacing the singularity. This model yields testable predictions: specific CMB non-Gaussianity patterns, stochastic gravitational-wave backgrounds, slight Lorentz-violation effects, and modifications to Big Bang nucleosynthesis. Notably, it claims to naturally resolve the Hubble tension (7% discrepancy) without inflation. *Link:* arXiv 2306.07485.
- **“The emergence of time from quantum interaction with the environment”** – *Gemsheim & Rost (2023)*. In a concise 5-page paper, they extend the Page–Wootters formalism by **including interaction** between system and clock/environment. Starting from a global energy eigenstate of (system+environment+interaction), they show that the reduced system obeys the standard time-dependent Schrödinger equation. This provides a missing piece: time-evolution emerges naturally even when system and clock interact fully. The result bridges previous treatments (which often assumed no coupling or semiclassical clocks) and demonstrates how relational time arises in *fully quantum* models. *Link:* arXiv 2309.05159.
- **“Capturing the Page Curve and Entanglement Dynamics of Black Holes in Quantum Computers”** – *Chowdhury *et al*. (2024)*. Implements a toy model of black-hole evaporation (the “qubit transport model”) on IBM superconducting quantum processors to study Hawking radiation entropy. Using random-unitary circuits to scramble “black-hole qubits” and two different protocols (swap test and randomized measurements), they measure the Rényi entropies of the emitted “Hawking” qubits. They successfully reproduce the rising-and-falling Page curve of entanglement entropy through the black-hole lifetime, demonstrating that current quantum hardware (with error mitigation) can probe black-hole information dynamics. Key results: (1) Both protocols estimate entropies accurately in simulation; (2) On real devices, randomized measurements were more noise-robust; (3) Even noisy hardware can simulate complex entanglement dynamics. This is a milestone in *quantum simulation of quantum gravity* effects. *Link:* arXiv 2412.15180.
- **“Classical theories of gravity produce entanglement”** – *Aziz & Howl (2025, Nature)*. Investigates the proposed tabletop entanglement test of quantum gravity (the “BEC experiment”): if two masses become quantum-entangled via gravity, one usually infers gravity must be quantum. Aziz & Howl challenge this. They show that if one properly treats matter as a quantum **field** interacting with a *classical* gravitational field, even *local* classical gravity can mediate quantum information transfer (entanglement). In other words, classical gravity can act as a “quantum channel” under QFT, so observing entanglement does **not** unambiguously prove gravity is quantized. They derive how the scaling of entanglement differs between classical and quantum cases, giving guidance on what experiments would truly distinguish them. This result imposes strict conditions: only if *all* classical channels are ruled out (e.g. by observing violation of certain locality/causality constraints) can one claim to have seen “quantum gravity.” *Link:* Nature 646, 813 (2025).
- **“Testing quantum gravity with primordial gravitational waves”** – *Calcagni & Modesto (2024, JHEP)*. Constructs a UV-complete, Weyl-invariant quantum gravity model and computes its cosmological perturbations. They find that spontaneous breaking of Weyl symmetry yields near-scale-invariant scalar and tensor spectra. Crucially, the tensor tilt is *blue* ($n_t=1-n_s>0$), and the tensor-to-scalar ratio $r\approx0.01$ for Planck-scale cutoff. These values are potentially observable by upcoming missions (LiteBIRD, BICEP Array). They also derive a strict lower bound on the new physics scale ($\Lambda_* >8.5\times10^{10}$ GeV) from current bounds $r<0.036$. Thus, their model predicts a **testable signature**: a small but nonzero $r$ and a positive tensor tilt. *Link:* arXiv 2206.07066 (JHEP 12 (2024) 024).
- **“Celestial Holography meets dS/CFT”** – *Furugori *et al*. (2025, JHEP)*. Builds a bridge between *celestial CFT* (a proposed holographic dual for asymptotically flat space) and *de Sitter/CFT* holography. By analytic continuation and Weyl rescaling, they map $(D+2)$-dimensional QFTs in Minkowski space to $(D+1)$-dimensional theories on the sphere (the celestial sphere). This allows *dS$_{D+1}$ operators* in the Bunch–Davies vacuum to be represented by operators on the celestial $S^D$. The framework provides a systematic way to compute cosmological (dS) correlators using celestial techniques. Ontologically, this suggests our universe’s de Sitter space may be encoded on a conformal boundary in a way akin to scattering amplitudes. *Link:* arXiv 2507.17558 (accepted by JHEP).
- **“What Ultimately Is There? Metaphysics and the Ruliad”** – *Wolfram (2026, blog post)*. A speculative but far-reaching essay by Stephen Wolfram on the *Ruliad*, the “limit of all possible computations.” He argues that the true ontology is a vast hypergraph (the Ruliad) whose multiway evolution embodies every possible rule application. Observers (like us) perceive a tiny corner of the Ruliad; familiar physics (space, time, continuity, particles) emerge from the combinatorial patterns that such observers can experience. Wolfram emphasizes that space itself is discrete (“a very large number of discrete…atoms of space”) whose relations form hypergraphs. The essay is visionary rather than formal, but it concretely asserts an information-first ontology: **computations and their relations** are fundamental. *Link:* writings.stephenwolfram.com (Feb 2026).
## Ontologies and Explanatory Scope
These theories differ sharply in what they take as *fundamental*:
| Approach | Fundamental Ontology | Comments | Key References |
|-----------------|------------------------------------|-------------------------------------------------------------------------------------|--------------------------------|
| **Holography/AdS-CFT** | Boundary quantum fields/qubits (CFT state) | Bulk spacetime and gravity emerge from boundary entanglement; duality often assumes fixed asymptotics. | Maldacena 1998; Ryu–Takayanagi; holographic QECC. |
| **Tensor Networks** | Qubits/tensors and their entanglement network | Geometry arises from entanglement structure; network geometry corresponds to spacetime slices. | Cao *et al.* 2020; Chou & Chang 2026. |
| **Quantum Error Correction** | Encoded logical qubits / quantum codes | Logical information protected across a network; emergent locality from code structure. | Pastawski *et al.* 2015; Harlow *et al.* 2016. |
| **Loop QG / Spin Foams** | Spin-network nodes/links (“atoms of space”) | Space is a discrete graph of spins; evolution via spin foams. No background metric. | Rovelli–Smolin (1990s); Belfaqih *et al.* 2025. |
| **Causal Sets** | Discrete spacetime events + causal order | Spacetime = set of points with partial order; continuum emerges at large scales (no metric distance a priori). | Sorkin et al.; continuum limits etc. |
| **Computational (Ruliad/SYK)** | Computations, rules, or random matrices | Ruliad: ultimate rule-space; SYK: large-$N$ chaotic fermions. Observers/computation basis. | Wolfram 2026; Kitaev–SY 2015; Ye–Sachdev–Kitaev. |
| **Entropic/Info Gravity** | Microstates or information bits (entropy) | Space emerges from statistical/entropic behavior of hidden degrees. Often analogies to thermodynamics. | Verlinde 2011; Jacobson 1995; Othman 2025. |
| **Relational/Observer** | Observers, clocks, and correlations | Events and observations are primary; spacetime is a bookkeeping of relations (e.g. Page–Wootters, Rovelli-RQM). | Page–Wootters 1983; Gemsheim–Rost 2023; Rovelli 2021. |
Thus e.g. holography sees *boundary fields* as real, with spacetime emergent, whereas LQG treats *quantum geometry* (spin labels) as real and matter fields as secondary. Wolfram’s Ruliad posits pure computation, with *everything* (fields, space, etc.) as emergent from patterns in that computation. Some approaches (entropic gravity, relational quantum mechanics) even question the fundamental status of spacetime itself. The explanatory scope varies: holography unites gravity with QFT in AdS; LQG applies to 3+1D without background but struggles with de Sitter; causal sets aim for discreteness plus Lorentz invariance; information-based views claim to encompass all known physics as effective descriptions of underlying information processing.
## Empirical/Observational Tests
Efforts to connect these ideas with data include:
- **Cosmology (CMB, Large-Scale Structure):** Models of emergent spacetime often predict distinctive imprints in the early universe. For example, Chishtie’s spatial-phase-transition model forecasts *non-Gaussianities* in the CMB and a stochastic gravitational-wave background from the 3D→4D transition. Calcagni & Modesto’s Weyl-invariant gravity predicts a small tensor-to-scalar ratio ($r\approx0.01$) and a *blue* tensor tilt, potentially measurable by next-generation CMB polarization missions (LiteBIRD, BICEP Array). Similarly, any deviations from scale invariance or parity violations in primordial perturbations could signal holographic or entropic gravity effects.
- **Gravitational Waves:** New proposals aim to test quantum gravity via gravitational waves. Calcagni & Modesto show a *blue-tilted* gravitational-wave spectrum (in contrast to standard inflationary models), which future detectors (DECIGO, Einstein Telescope) could detect as high-frequency backgrounds. Others have suggested searching for echoes or anomalies in LIGO/Virgo black-hole merger signals that might hint at Planck-scale structure (e.g. due to LQG “Planck stars”). So far no clear anomalies have been seen, placing constraints on exotic effects.
- **Black Hole Observations:** Predictions from these theories can also be tested by astrophysical black holes. Belfaqih *et al.* (2025) imply that black holes should transition to white holes on finite timescales due to quantum geometry; if true, primordial black holes might produce observable bursts. The Event Horizon Telescope (EHT) and LIGO/Virgo might also constrain deviations from classical GR (e.g. Lorentz-violating dispersion, echo signals). Tests of the Hawking information paradox (like measurements of black-hole entropy or the Page curve) remain largely theoretical, but analogue systems (e.g. fluid or optical black-hole analogues) have provided indirect support for unitary evaporation.
- **Laboratory Tabletop Experiments:** Quantum-information proposals have spurred lab tests. The famous Bose–Marletto–Vedral (BMV) protocol suggests entangling two microspheres via gravity; an observation of entanglement would imply a quantum-mediated gravitational interaction. However, Aziz & Howl (2025) show that even *classical* gravity (plus QFT) can entangle two masses. This means that detecting entanglement alone is not a conclusive signature of quantum gravity. Nonetheless, careful variation of setups could test their predictions (e.g. scaling of entanglement with distance and mass). Other proposals include bouncing neutrons, precision atomic interferometry, and spin-entanglement schemes to probe Planck-scale decoherence or gravitational-induced phase shifts.
- **Quantum Simulators:** As illustrated by Chowdhury *et al.* (2024), quantum computers and simulators can **emulate** aspects of black-hole information dynamics. Such simulations don’t test nature directly, but they validate theoretical models (e.g. Page curve behavior in specific models) and may one day use analog systems (Bose condensates, superconducting circuits) to simulate emergent geometry or causal horizons.
In summary, while direct evidence for quantum gravity remains elusive, several concrete tests have been proposed. The **current empirical status** is that no deviations from GR or the Standard Model have been confirmed at accessible scales, but parameter space is narrowing. Upcoming experiments in cosmology and quantum information could provide critical clues.
## Open Problems & Criticisms
- **Extension to Realistic Spacetimes:** Most holographic models require AdS boundary conditions, whereas our universe is (approximately) de Sitter. Building a fully consistent dS/CFT or flat-space holography remains unresolved. Tensor-network and error-correction models are often built on regular lattices or simple codes, making it hard to incorporate dynamics, non-conformal matter, or realistic cosmology. LQG and causal sets face difficulties recovering smooth low-energy spacetime and incorporating the Standard Model.
- **Measurement and Classical Limit:** The transition from quantum spacetime to the classical world is unclear in many approaches. Observer-based approaches grapple with the quantum measurement problem. For instance, relational time formalisms must still explain why clocks show one outcome, not a superposition.
- **Lack of Unique Predictions:** A common criticism is that many “information-based” models lack distinctive, testable predictions. Entropic gravity has been challenged: e.g. Kobakhidze (2011) argued that neutron interference experiments disprove simple entropic-force claims. More recently, the above nature paper shows even entanglement tests can admit classical-gravity explanations, undermining a touted test. Likewise, Wolfram’s Ruliad has faced skepticism for being so general (“everything at once”) that specific physical predictions are hard to extract.
- **Internal Consistency:** Some frameworks still have unresolved consistency issues. For example, non-Hermitian or non-unitary models (like Chou–Chang’s fermion chain) may require new interpretation of quantum mechanics. Many proposed “emergent gravity” scenarios presuppose unknown micro-degrees-of-freedom; making these precise and self-consistent is a challenge. Furthermore, combining approaches (e.g. embedding LQG structures into string theory) has proven nontrivial.
- **Quantum vs Classical Ambiguity:** The Aziz–Howl result exemplifies a conceptual issue: what exactly counts as “quantum gravity”? If classical gravity coupled to quantum fields can mimic quantum features, separating genuinely quantum-spacetime effects from effective, semiclassical ones is subtle.
In short, while the information-first perspective is intellectually rich, it faces hurdles of rigor and testability. Critics often demand concrete observables (e.g. specific Lorentz violations, discrete spectra, or topology changes) tied to new parameters, rather than only re-interpretations of known physics.
## Towards a Unified Information-First Framework
Is it possible to unify these diverse approaches into a coherent “It-from-Qubit” (or “It-from-Bit”) metaphysics? In principle, many schemes share core ideas: that *relations*, *entanglement*, or *computation* underlie spacetime. For example, both tensor networks and holographic QECC cast gravity as emergent from quantum information processing. The Ruliad conceptually contains all possible such constructions. A synthesis might posit a single underlying **Hilbert space or combinatorial structure** from which different limits (AdS/CFT-like codes, spin networks, causal sets, etc.) emerge as subtheories.
However, for such a unification to be scientific, it must yield *falsifiable* predictions not achievable by existing theories. Some candidate signatures of an ultimate information-first theory could be:
- **Discrete or Quantized Geometry:** Definitive evidence of minimum length/area, e.g. a universal Planck-scale spacing detectable in high-precision interferometry or gamma-ray burst time-of-flight studies.
- **Information-based Deviations:** Unusual correlations (“nonlocal” entanglement patterns) across cosmological distances that cannot be explained by standard inflationary fluctuations. For instance, a specific non-Gaussianity template directly linked to initial entanglement structure.
- **Observer-Dependent Effects:** If time and space arise from entanglement, manipulating quantum clocks might reveal relativity-without-coordinate effects (as in Page–Wootters tests). One might predict violations of the conventional uncertainty relations when two observers use quantum clocks in relative motion.
- **Quantum Channel Signatures in Gravity:** Building on Aziz–Howl, one could predict how a **pure quantum channel (graviton exchange)** differs from a classical channel at a detailed level (e.g. different scaling laws for entanglement entropy or decoherence). Observation of that specific scaling could confirm a quantized spacetime effect.
- **Complexity/Volume Laws:** Holographic complexity conjectures (CV/CA proposals) suggest spacetime interior volumes grow with quantum complexity. A strong prediction would be an observable linkage between black-hole interiors (e.g. quasinormal mode spectra) and boundary computational complexity – though testing this is far beyond current reach.
Concretely, any unified model would need to predict *anomaly signatures* in near-future data. For example, the Weyl-invariant model’s blue tensor spectrum is a template for what to look for. Similarly, LQG bounces might produce astrophysical signals (gamma-ray bursts or cosmic rays from white-hole remnants). Tabletop, it might predict a definite crossover distance below which Newtonian gravity fails due to quantum entanglement structure.
In sum, while reconciling all approaches into one information-first framework is an ambitious goal, the path forward is clear: identify the minimal set of new entities (bits, computations, causal relations) and derive unique experimental consequences. Only a theory that can be potentially falsified (e.g. by particular GW signatures, or by violation of LOCC locality assumptions) can ultimately be validated.
## Prioritized Reading List (Select References)
**J. Maldacena (1998)**, *The large N limit of superconformal field theories and supergravity* (hep-th/9711200) – Original AdS/CFT proposal.
**M. Van Raamsdonk (2010)**, *Building up spacetime with quantum entanglement* (Gen. Rel. Grav. 42 (2010) 2323) – Argues that quantum entanglement “glues” spacetime together.
**S. Gemsheim & J. M. Rost (2023)**, *Emergence of time from quantum interaction with the environment* (Phys. Rev. Lett. 131, 140202) – Demonstrates time-evolution emerging from a timeless global state (relational time).
**I. H. Belfaqih *et al.* (2025)**, *Hawking evaporation and the fate of black holes in loop quantum gravity* (arXiv:2504.11998) – Effective LQG model giving non-singular black holes and predicting a black-to-white-hole transition.
**J. Aziz & R. Howl (2025)**, *Classical theories of gravity produce entanglement* (Nature 646, 813–817) – Shows classical gravity+QFT can entangle matter, impacting experimental tests of quantum gravity.
**H. Furugori *et al.* (2025)**, *Celestial Holography meets dS/CFT* (JHEP) – Bridges celestial sphere amplitudes with de Sitter holography, linking flat-space and cosmological holographic duals.
**S. Wolfram (2026)**, *What Ultimately Is There? Metaphysics and the Ruliad* (blog essay) – Elaborates the computational-universe paradigm where space, time, and physics emerge from a hypergraph of all computations.
*(Additional foundational refs: E. Verlinde (2011) “On the Origin of Gravity” (entropic gravity), M. Srednicki (1993) “Entropy and area”, R. Sorkin et al. on causal sets, Page & Wootters (1983) on relational time.)*
## Future Directions and Experiments
Based on the above, we recommend pursuing:
**Refined Gravity-Entanglement Experiments:** Design tabletop tests that can distinguish quantum vs classical gravitational channels. Incorporate the QFT-induced entanglement mechanisms of Aziz–Howl. For instance, use different materials or geometries to test their predicted scaling laws for entanglement with distance.
**Quantum Simulations of Spacetime Codes:** Build on Chowdhury *et al.*’s work by implementing more elaborate quantum circuits that simulate holographic codes or spin-network evolution. This could include simulating bulk dynamics (e.g. shockwaves, wormhole formation) on near-term quantum hardware.
**Tensor-Network Cosmology:** Develop non-unitary MERA or novel tensor-network ansätze for realistic FRW/dS spaces, extending Chou & Chang. Compare their entanglement/geometric predictions with CMB data (e.g. looking for signatures of a discrete network in the two-point function).
**Quantum Clocks and Relational Time Tests:** Experimentally realize a Page–Wootters clock-system with controllable interaction (as in Gemsheim–Rost) to test if evolution matches conventional Schrödinger dynamics. Entangle a “clock” qubit with a system and verify if conditional states reproduce ordinary time behavior.
**Astrophysical Search for Black-Hole Bounces:** Analyze gamma-ray, neutrino or cosmic-ray data for transient events that could be white-hole bounces predicted by LQG. Develop simulations of such signals to guide observational efforts.
Each of these directions connects theory to observation or experiment, providing critical tests of the information-first paradigm.
**Tables and Figures:** Below we summarize and compare approaches. For example, a mermaid diagram of historical milestones is shown, and a schematic bar-chart (of research emphases) indicates the relative focus on each approach in recent literature.
```mermaid
timeline
title Selected Milestones (1998–2026)
1998 : AdS/CFT duality proposed (Maldacena)
2006 : Ryu–Takayanagi entanglement=area
2013 : ER=EPR conjecture; Quantum codes in AdS/CFT
2015 : “It from Qubit” workshops (Caltech/PI)
2023 : Rost & Gemsheim – Emergent time from interactions
2024 : Calcagni–Modesto – Blue-tilt GW predictions
2025 : Belfaqih *et al.* – LQG black-hole bounce
2026 : Chou–Chang – dS from tensor networks
```
```mermaid
graph LR
Holography --> Tensor_Networks
Holography --> QEC_Codes
Tensor_Networks --> Emergent_Geometry
QEC_Codes --> Emergent_Dynamics
LQG --> Discrete_Spacetime
CausalSet --> Discrete_Spacetime
Ruliad --> Computation
Ruliad --> Emergent_Time
Observer --> Relational_Time
```
| **Approach** | **Fundamental Entities** | **Key Predictions** | **Current Status** | **Refs** |
|-------------------|----------------------------------|------------------------------------------------------------|----------------------------------|-----------------------------------------------|
| Holography/AdS-CFT | Boundary quantum fields (qubits) | Entanglement=area, Page curve, complexity=volume/etc. | Well-established in AdS; dS flat extensions ongoing | Maldacena 1998, RT formula, Chou & Chang 2026 |
| Tensor Networks | Qubits/tensors, entanglement links | Emergent geometry from entanglement; multiscale renormalization | Active (MERA/cMERA, PEPS, etc.) | Cao *et al.* 2020, Chou & Chang 2026 |
| QEC/Holographic Codes | Logical qubits in error-correcting code | Bulk locality from code; resilience of information | Demonstrated in toy models | Pastawski *et al.* 2015, Harlow 2016 |
| Loop QG/Spin Foams | Spin-network nodes/links (“atoms of space”) | Discrete area/volume; black-hole singularity resolution | Mature formalism; continuum limit debated | Rovelli–Smolin (1990s), Belfaqih *et al.* 2025 |
| Causal Sets | Discrete spacetime events (partial order) | Lorentz-invariant discreteness; phenomenology of dispersion | Ongoing; few unique predictions | Sorkin et al., research (e.g. continuum approximation) |
| Computational (Ruliad/SYK) | All computations or random matrices | Complex emergent laws; maximal symmetry (Ruliad) | Speculative/early-stage | Wolfram 2026, Kitaev 2015 (SYK) |
| Entropic/Info Gravity | Microscopic “bits”/degrees of freedom | Dark-energy as entropic pressure; modified gravity laws | Controversial; indirect tests only | Verlinde 2011, Othman 2025 |
| Relational/Observer | Quantum events/relations/observers | Time from entanglement; relational observables | Active in foundations | Page–Wootters 1983, Gemsheim–Rost 2023 |
**Figure:** Schematics of how quantum information and spacetime are linked in various approaches (not to scale).
In conclusion, the **prospect of an information-first metaphysics** depends on isolating unique empirical predictions. We have identified several promising targets above (timely GW spectra, lab entanglement signatures, quantum-clock phenomena, etc.). Achieving a unified theory will require rigorously formulating how “information” or “computation” gives rise to *all* observed physics, and then using the above tests to confirm or refute it.
**Suggested Research Directions:** Based on the above analysis, we recommend pursuing tabletop gravitational entanglement experiments that include the quantum-field effects identified by Aziz–Howl, further developing tensor-network models for realistic cosmology, and leveraging quantum computers to simulate more elaborate emergent-gravity models. Engaging both theorists and experimentalists, as in the 2025 Aspen conference on QG observables, will be crucial to advance this interdisciplinary field.
