Representation contract
A numerical cosmology with the uncertainty left visible.
The 3D volume is one statistically seeded realization. The background expansion, thermal state, recombination history, light-element abundances, matter power, and CMB spectrum come from research solvers. Where tested physics ends, the page changes category instead of inventing certainty.
01 · CALCULATEDState of the universe
CLASS evolves the FLRW background and linear perturbations; HyRec supplies the finite ionization and visibility history; PRIMAT evolves neutrinos and the nuclear reaction network.
02 · SIMULATEDOne possible realization
The particular particle phases, CMB hot and cold spots, camera, and visible micro-motion are seeded display realizations. They are not a reconstruction of our exact patch of sky.
03 · NOT CLAIMEDPhysics beyond the model
No tested theory supplies the Planck era. The page does not simulate baryogenesis, nonlinear galaxy formation, baryonic feedback, quantum gravity, proton decay, or vacuum stability.
Solver closure
Six numerical anchors
These values are read from the same compact reference tables that drive the animated state. They are not hard-coded decorative labels.
| Quantity | Reference run | Engine |
|---|
| Age of universe | — | CLASS background |
| Visibility peak | — | HyRec |
| Drag sound horizon | — | CLASS thermodynamics |
| Primordial ⁴He mass fraction | — | PRIMAT |
| Primordial D/H | — | PRIMAT |
| First TT acoustic peak | — | CLASS perturbations |
Active numerical pipeline
Every displayed state, exposed.
The cards below update from the same interpolated solver row used by the renderer. Equations are the physical transforms; substitutions show the live numerical result. Values marked unavailable are outside that solver’s domain rather than silently extrapolated.
calculating now
01 · logarithmic clockexact transform
——
Browser arithmetic · IEEE-754 double precision
02 · expansion ratesolver
——
CLASS background or Friedmann thermal closure
03 · scale and redshiftFLRW
——
CLASS background · scale factor normalized to a₀ = 1
04 · energy closureflat baseline
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CLASS density fractions · Planck-like flat ΛCDM reference
05 · causal scaleparticle horizon
——
CLASS conformal time; fixed-Λ event horizon after today
06 · epoch microphysicsactive layer
——
Current epoch engine
Current governing relation
Radiation-era expansion
Energy and entropy degrees of freedom change across particle thresholds, so temperature does not simply scale as the inverse scale factor.
MODEL · STANDARD MODEL EOS
The thermal bath calculation begins only after reheating. Its maximum temperature and starting time are not measured.
Science status · July 2026
Reference baseline ≠ final cosmology.
The run stays on a reproducible flat Planck-like ΛCDM baseline. It does not quietly retrofit every new tension. DESI DR2’s BAO analysis, combined with CMB and supernova samples, strengthened—but did not settle—evidence for evolving dark energy; that is why the far future remains explicitly conditional. ACT DR6 now supplies state-of-the-art small-scale CMB maps and spectra, while this realization continues to use the declared CLASS baseline so every number remains internally consistent. DESI DR2 · ACT DR6
Primary numerical sources
CLASS — Blas, Lesgourgues & Tram 2011; Lesgourgues 2011. Background, perturbations, lensed CMB spectrum, and matter power. The embedded table records source commit —.
HyRec-2 — Lee & Ali-Haïmoud 2020. Sub-millisecond high-accuracy recombination and Thomson visibility through CLASS.
PRIMAT 0.3.2 — Pitrou, Coc, Uzan & Vangioni. Neutrino thermodynamics, nuclear reaction network, and primordial abundances.
Standard Model equation of state — Saikawa & Shirai 2018. Published energy and entropy degrees of freedom across particle thresholds.
Baseline parameters — Planck Collaboration VI 2020: flat six-parameter ΛCDM with one 0.06 eV massive-neutrino species.
DESI DR2 + ACT DR6 — current observational context. These results inform the uncertainty labels; they do not alter the declared reference run.
Structure layer — first-order Lagrangian/Zel’dovich displacement normalized to the CLASS matter power spectrum. Not N-body or hydrodynamics.