Cosmology in the Browser

Place any observer anywhere on the 13×13 galaxy grid. Every galaxy around them recedes at a rate proportional to distance — the Hubble flow — and every galaxy sees precisely this same pattern. No observer is privileged; no galaxy is the true centre. This is the Copernican Principle made interactive. The H₀ slider spans the Hubble Tension: H₀ = 67.4 km/s/Mpc (Planck 2018, from the CMB) versus 73.0 km/s/Mpc (SH0ES, from Cepheids and Type Ia supernovae). The 5σ discrepancy between these two values is one of the most significant open problems in modern cosmology. Drag the observer and change H₀ to confirm that the answer — “I am at the centre” — is the same regardless.

ω Cen’s multiple stellar populations, retrograde orbit, and abnormally large mass for a globular cluster all point to the same origin: it is the preserved nuclear star cluster of a dwarf galaxy that was tidally disrupted by the Milky Way over a 12 Gyr infall. This tool animates that stripping history. The progenitor mass sets how large the original galaxy was (10≰M—10͑⁰ M⊙); the pericentre sets how violent each close passage was; the nuclear fraction sets how much mass was retained in the nucleus relative to what was stripped. The IMBH is the inherited memory of the galaxy that was. A tighter pericentre with a larger nuclear fraction produces a more massive, more concentrated remnant — and a better seed for the IMBH candidate we observe today.

Lee Smolin (1992) proposed that universes reproduce via black holes, and that natural selection has tuned the constants of physics toward maximal BH production. Clément Vidal’s Cosmological Artificial Selection extension (2014) asks whether advanced civilisations could participate in that selection by engineering new universes. This tool lets you tune G, α, Λ, and the proton/electron mass ratio and watch the BH production rate — and the habitability for complex life — change in real time. Our universe’s constants sit near but not at the fitness peak: slightly increasing G and slightly decreasing Λ increases BH production. The small distance from the optimum is consistent with multiple rounds of cosmic selection — or with weak anthropic selection for life alongside BH fecundity.

John Smart’s Transcension Hypothesis (2012) argues that all sufficiently advanced civilisations follow a developmental trajectory that compresses their Space, Time, Energy, and Matter toward a black-hole-like endpoint — rather than expanding outward toward the stars. Each STEM dimension maps to a physical quantity set by the black hole’s mass: Space → Schwarzschild radius r_s, Time → 1 / f_ISCO, Energy → Hawking temperature T_H, Matter → Bekenstein entropy S_Bek. For ω Cen’s 8,200 M⊙ IMBH, the full STEM endpoint is physically realised already — the black hole is the compression completed. The four sliders show how far along each dimension a civilisation has progressed; full compression is the IMBH. The Fermi Paradox implication: transcended civilisations are not absent but invisible, operating at sub-arcsecond scales inside their own black holes.