Proposed "Cosmic Maturity Index" (CMI) - Logarithmic Scale (1-10)

• CMI ~ 1-2 (Level 0: Mythic/Dogmatic Small Universe):

  • Age: Thousands of years (10³ - 10⁴ years).

  • Size: Earth-centric, or a small, contained cosmos (e.g., a celestial sphere a bit beyond the planets). Effectively 10⁰ - 10¹ "solar system units" in perceived extent beyond immediate surroundings.

  • Example: Literal creationist views, some ancient mythologies.

• CMI ~ 3-4 (Level 1: Early Observational, Geocentric/Early Heliocentric):

  • Age: Still thousands to perhaps tens of thousands of years (10⁴ - 10⁵ years).

  • Size: Solar system well-defined, stars seen as distant but perhaps within a single, large sphere. Size might be 10² - 10⁴ solar system units.

  • Example: Ptolemaic system, early Copernican views before stellar distances were appreciated.

• CMI ~ 5-6 (Level 2: Newtonian/Galactic Universe):

  • Age: Millions to perhaps a few hundreds of millions of years, as geological and early evolutionary ideas take hold (10⁶ - 10⁸ years).

  • Size: Our galaxy (the Milky Way) understood as a vast collection of stars. Distances to nearby stars measured. Size is 10⁵ - 10⁷ light-years (order of galactic scales).

  • Example: Post-Newton, Herschel's mapping of the galaxy, pre-Hubble understanding of nebulae.

• CMI ~ 7-8 (Level 3: Expanding Universe of Galaxies, Early Big Bang):

  • Age: Billions of years, but perhaps initial estimates are lower than current ones (e.g., 10⁹ - 10¹⁰ early years).

  • Size: Universe understood as composed of many galaxies, expanding. Observable universe concept emerges. Size is 10⁸ - 10⁹ light-years.

  • Example: Hubble's discoveries, early Big Bang models (pre-CMB precision).

• CMI ~ 9 (Level 4: Precision Cosmology - ΛCDM):

  • Age: Precisely constrained to around 10¹⁰ years (specifically ~13.8 billion).

  • Size: Observable universe precisely constrained to around 10¹⁰ - 10¹¹ light-years (specifically ~93 billion light-years diameter). Dark matter/energy incorporated.

  • Example: Current standard cosmological model based on CMB, supernovae, etc.

• CMI ~ 10 (Level 5: Acknowledgment of Ultimate Unknowability/Trans-ΛCDM):

  • Age: Explicitly states "older than we can ever definitively know" or "current models give ~10¹⁰ years but this is likely a lower bound or model-dependent." Recognizes the possibility of pre-Big Bang epochs or cyclical models not captured by a single "age."

  • Size: Explicitly states "larger than we can ever definitively know" or "observable universe is ~10¹¹ light-years, but the total extent is unknown/unknowable, potentially infinite or part of a multiverse."

  • Philosophical Stance: Deep understanding of model limitations, observational horizons, and the philosophical implications of trying to define the "total" size and age. Focus is on the limits of perception and knowledge.

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