OCS Research · Preprints
The Omega Centauri Research Papers
Five companion preprints (Swanson 2026) develop and test a single idea: that the thermodynamics of computation, rather than the urge to expand, predicts where the oldest technological civilizations end up, and that Omega Centauri (NGC 5139) is the most accessible place to look. Read each abstract below, or open the full paper.
Paper A · The hypothesisThe Macro Transcension Hypothesis: Spinning Black Holes in Dense Stellar Clusters as Thermodynamic Attractors for Advanced Civilizations, with Omega Centauri as an Observational Test Bed
AbstractMost proposed resolutions of the Fermi paradox assume that long-lived technological civilizations either expand outward, perish, or deliberately hide. We develop a fourth alternative, the Macro Transcension Hypothesis (MTH): that civilizations which optimize for long-term computation are driven by thermodynamics, rather than preference, toward a specific class of astrophysical environment, namely rapidly spinning massive black holes embedded in dense, old stellar systems, and that the migration and its endpoint are both electromagnetically quiet. The MTH extends the transcension hypothesis of Smart (2012) from planet-scale “inner space” to macroscopic black-hole infrastructure, and differs from the aestivation hypothesis of Sandberg, Armstrong & Ćirković (2016) in requiring no waiting strategy: the relevant free-energy and entropy-disposal advantages are available now. We quantify the case in four steps: (i) thin-disk accretion onto a Kerr black hole releases 5.7–42 per cent of rest-mass energy, versus 0.7 per cent for hydrogen fusion, while magnetically arrested disks extract additional spin energy at effective efficiencies exceeding 100 per cent of accreted rest mass; (ii) by the generalized second law, an event horizon is a thermodynamically ideal entropy sink, and a worked delivery budget shows the realized erasure cost lands a factor of ~106–109 below the CMB-limited Landauer floor once carrier propagation and delivery overheads are charged, with little radiated waste heat; (iii) the Bekenstein–Hawking entropy of a ~2×104 M☉ black hole corresponds to ~1086 bits, exceeding any material archive; and (iv) per unit of harvested mass, this architecture outperforms complete fusion of the same fuel by a factor of ~11–85, outperforms Dyson-type stellar harvesting without star lifting by ~80–600 in lifetime energy yield (~11–85 against a star-lifting economy), and exceeds a solar Dyson swarm by a factor of ~109 (6.6×108 at 2×104 M☉) in instantaneous Eddington-limited power. We then identify Omega Centauri (NGC 5139), a ~4×106 M☉, ~12-Gyr-old stripped dwarf-galaxy nucleus hosting the nearest strong candidate intermediate-mass black hole, as the most observationally accessible system satisfying the MTH selection criteria, and present a falsification framework built on six instrument-matched tests: accretion-luminosity limits (JWST, ATCA), mid-infrared waste-heat limits, LISA mass and spin measurements (contingent on a compact-object inspiral occurring in-band during the mission), millisecond-pulsar timing, stellar proper-motion accelerations, and neutrino burst searches (KM3NeT). Current data, including the unresolved tension between a ≥8,200 M☉ kinematic lower bound (Häberle et al. 2024) and a ≲6,000 M☉ pulsar-timing upper bound (Bañares-Hernández et al. 2025) and the complete electromagnetic silence of the central object (Mahida et al. 2026; Chen et al. 2025), are consistent with both the MTH and the more parsimonious gas-starvation null hypothesis; we state explicitly which forthcoming observations would discriminate between them, and which would falsify the MTH outright. The hypothesis is offered in the falsificationist tradition of Sandberg, Armstrong & Ćirković (2016) and Dvali & Osmanov (2023): a speculative but physically grounded working model whose value lies in the concrete observational program it motivates.
Full paper → Paper B · The reviewInward Resolutions of the Fermi Paradox: A Critical Review of Migration Down Thermodynamic Gradients
AbstractMost catalogued resolutions of the Fermi paradox modify one of three things: the abundance of technological life, its longevity, or its visibility. A smaller family modifies its direction: these are the inward-migration hypotheses, which hold that mature technological intelligence does not expand outward across space but migrates down thermodynamic gradients, toward denser, faster (serially), colder, and more computationally efficient configurations of matter, and that the observed silence of the sky is the external appearance of this migration. The family comprises six distinguishable proposals, built on a precursor lineage spanning six decades, from Dyson's eternal-computation bound to Bradbury's Matrioshka-brain engineering: the migration hypothesis of Ćirković and Bradbury, Smart's transcension hypothesis, Vidal's stellivore interpretation, the aestivation hypothesis of Sandberg, Armstrong and Ćirković, black-hole computing proposals from Inoue and Yokoo through Dvali and Osmanov, and the recent Macro Transcension Hypothesis. These proposals share a single load-bearing premise: that the thermodynamics of computation, rather than expansion, reproduction, or communication, is the correct lens for predicting the behaviour of the oldest intelligence. Yet they have not been reviewed as a family, their mutual inconsistencies have not been catalogued, and their sharply varying degrees of falsifiability have not been graded. This review attempts all three. We reconstruct the family tree and its intellectual debts; restate the unifying physics (Landauer's principle, the Margolus–Levitin bound, Bekenstein–Hawking entropy, and the temperature hierarchy of available entropy sinks) with explicit numbers; construct a comparative matrix of assumptions, energy logics, predicted observables, standing objections, and current observational status for each member; and grade each against six falsifiability criteria, from named-target specificity to resistance to unfalsifiability-by-relocation. We then situate the family against its chief sociological competitors (zoo, dark-forest, and sustainability solutions), which predict the same silence from different premises, and argue that the inward family's distinguishing virtue is residue: thermodynamic optimization leaves dynamical and high-energy traces that fear and ethics do not. Open problems (goal stability over 108-year horizons, migration economics under Bostrom-type opportunity costs, the incomplete-compliance gap, and population-level consistency with grabby-aliens selection effects) are stated as research questions. We close with the observational program: the instrument-matched tests now feasible for each hypothesis, anchored by the first dedicated globular-cluster technosignature surveys and the multi-messenger campaign now proposed for Omega Centauri.
Full paper → Paper C · The observational campaignA Multi-Messenger Technosignature and Anomaly-Detection Campaign for Omega Centauri
AbstractOmega Centauri (NGC 5139), the most massive Galactic globular cluster and the probable stripped nucleus of an accreted dwarf galaxy, presents a unique conjunction of observational circumstances: the strongest current candidate for an intermediate-mass black hole (IMBH) in the Galaxy, anchored by seven stars moving above the local escape velocity (Häberle et al. 2024a); a formally unresolved factor-of-several tension between kinematic lower bounds (≥8,200 M☉) and a pulsar-timing upper bound (≲6,000 M☉; Bañares-Hernández et al. 2025); complete electromagnetic silence to the deepest radio and infrared limits ever placed on a globular cluster core (Mahida et al. 2026; Chen et al. 2025); and a southern declination optimal for the newest southern-hemisphere facilities. No dedicated technosignature search of ω Cen has ever been conducted at any wavelength. We present a coordinated, hypothesis-agnostic, multi-messenger campaign of eight instrument-matched programs (enumerated in Section 1) spanning infrared imaging, radio timing and SETI, astrometry, gravitational waves, neutrinos, gamma rays, the optical time domain, and archival channels, addressing conventional astrophysics (IMBH reality, mass, and spin; cluster dynamics) and technosignature hypotheses with the same data. For each program we state quantitative sensitivities, time requests, decision thresholds, and explicit falsification criteria, including negative results: direct astrometric acceleration detection of the fast stars is below 1σ at nominal parameters before ~2040, so the decision-grade astrometry routes through photocentric-wander and reference-frame measurements instead. Total cost is ≲ US$10M over 2026–2035, most of it archival analysis and piggyback observing; the decisive mass and spin measurements arrive as by-products of planned LISA mission science. Every null result constrains conventional astrophysics, and no anomaly claim advances without confirmation from at least two independent messengers; under realistic outcomes the campaign adjudicates the astrophysical hypotheses, while the technosignature hypothesis is constrained only along specific low-probability branches.
Full paper → Paper D · The economicsThe Economics of Inward Migration: Relocation versus Densification for Computation-Maximizing Civilizations
AbstractThe inward-migration resolutions of the Fermi paradox hold that computation-optimizing civilizations relocate to thermodynamically privileged environments, with rapidly spinning intermediate-mass black holes (IMBHs) in dense old clusters as the strongest candidate destination. Bostrom (2003) priced the opportunity cost of delayed expansion and Bennett et al. (2019) priced the losses of dormancy, but relocation itself, the abandonment of accumulated local infrastructure for a transit of 104–106 years toward a large deferred payoff, has never been priced. This paper treats that trade as a decision problem over a common utility (discounted integrated computation) with three strategies: stay-and-densify (Matrioshka-style local engineering), migrate (beamed-sail relocation to the nearest suitable IMBH cluster), and seed-and-stay (a self-replicating seed dispatched while densification continues at home). Using payoff kernels assembled from established physics, we derive closed-form crossover conditions. The central result is a threshold on the effective discount-plus-hazard rate: migration dominates densification whenever ρ + λ < ln(G ps)/τ, where G is the destination computation-rate multiplier (106–109 on power alone, depending on fuel imports), ps the transit survival probability, and τ the transit-plus-construction time. At fiducial parameters the threshold is ρ + λ ≲ 2×10−4 yr−1: any lineage whose combined discount-plus-hazard half-life exceeds roughly 3,500 years should migrate. The seed-and-stay hybrid dominates both pure strategies throughout the migration-favourable region and in a band extending modestly beyond the threshold (to ρ + λ ≈ 1.7 ρ* at a physical seed cost f = 10−6), because seed mass is a negligible fraction of local output; beyond that band the exponential discount on the deferred payoff extinguishes the seed's value. Embedding the decision rule in a mixed population quantifies how much inward migration thins the expected loud population, and yields a new population-level residue: the predicted sky ratio of Matrioshka-type infrared sources to quiet-cluster systems, which archival infrared nulls constrain once residue lifetimes are folded in. All results are conditional on the optimization premise shared by the hypothesis family; the contribution is the pricing structure, not the premise.
Full paper → Paper E · The engineering and the adjudicationEngineered Intermediate-Mass Black Hole Systems: Infrastructure Constraints, Observable Residue, and a Multi-Messenger Adjudication Framework
AbstractThe inward-migration resolutions of the Fermi paradox identify rapidly spinning intermediate-mass black holes (IMBHs) in dense, old stellar clusters as thermodynamically privileged destinations for computation-optimizing civilizations. Previous papers in this series argued the thermodynamic case (A), surveyed the hypothesis family (B), designed a multi-messenger campaign for the nearest candidate, Omega Centauri (C), and priced the migration decision (D). This paper addresses the two remaining questions. First, feasibility: whether large-scale computational infrastructure can persist around a Kerr IMBH embedded in a live cluster core (stellar density ~3×103 M☉ pc−3, velocity dispersion ~21 km s−1). Extending recent passive-stability results for stellar engines and Dyson bubbles to the combined Kerr-plus-cluster potential, and combining analytic tidal, thermal, and material limits with a Monte Carlo of gravitationally focused stellar flybys, we derive an allowed envelope for a fiducial 2×104 M☉ hole in the ω Cen core: precession-tolerant swarms survive passively from ~102 gravitational radii out to the cluster stripping radius at ~4×103 AU. Stellar flybys never set the boundary, and the margin is larger than an impulsive treatment shows. The Monte Carlo, run with a mass-segregated heavy-remnant perturber component (31 M☉ black holes at 0.1–3 per cent number fraction), yields a conservative impulsive floor of ~6×107 yr at the fiducial 1 per cent fraction (3×109 yr without remnants); but unbound cluster stars are adiabatically decoupled from every orbit in the envelope, and applying the standard correction lifts the physical lifetime to ≳3×108 yr at the envelope edge and to the cluster age within ~3 AU. The relaxed Bahcall–Wolf cusp around the hole is no longer a conditional: the González Prieto et al. (2025) realizations form one at 300 Myr with γ ≃ 1.75, steepening to γ ≃ 2 for the heavy remnants. Tidal disruption events set the hazard-recurrence horizon (≳107 yr), and the measured intracluster medium funds, via Bondi accretion at magnetically arrested efficiencies, a power budget of up to ~8×105 L☉, provided the standard outflow suppression of hot low-Eddington flows is itself suppressed, an engineered capability; the natural suppressed supply is ~103 L☉, at or below the thermal-concealment ceiling. For the engineered case supply never binds; thermal concealment does. An abandoned deep swarm grinds to debris on an estimated ~103 yr timescale and is then drained by the hole, leaving spin as the only durable fossil of engineered history. Second, residue and adjudication: the envelope implies three forward-modeled observables, a temperature-dependent waste-heat floor, a magnetically-arrested-disk (MAD) regulation signature, suppression of the flux-eruption variability characteristic of natural MAD accretion, and environmental dephasing of any extreme-mass-ratio inspiral, the only channel that constrains engineered mass. We construct a hierarchical Bayesian framework, with per-messenger Bayes factors against an explicit menu of astrophysical nulls (quiescent IMBH; stellar-remnant subcluster) combined through coincidence likelihoods of the kind developed for gravitational-wave counterpart searches, and with pre-registered decision thresholds. Applied to the current ω Cen data, the framework yields a Bayes factor mildly favoring the astrophysical nulls (ln K = −0.29 from the mid-infrared channel, marginalized over swarm radius); the value is a demonstration of the machinery, dominated by the dormancy prior rather than by the data, and moves toward −0.1 under an outflow-truncated fuel ceiling. The framework's present product is the information forecast: how much each planned observation from Paper C can move the odds. All results are conditional on the optimization premise shared by the hypothesis family; the contribution is the feasibility envelope, the forward-modeled residue, and the adjudication machinery.
Full paper →