Block 1 · The impossible galaxies
JWST found galaxies that shouldn't exist. They had twice as long as anyone thought.
The James Webb Space Telescope has discovered massive, mature galaxies at redshifts beyond z = 13 — a time when the standard model gives only 330 million years since the beginning. These galaxies look like they need 500–800 million years to form. The field has scrambled: exotic star formation, primordial black holes, modified feedback. All trying to explain how you build an adult galaxy in a toddler's timeframe.
ISST's committed expansion history gives 633 million years at z = 13. Not fitted to JWST — the parameters were set by supernova data years before these galaxies were discovered. The required star-formation efficiency drops from physically implausible (ε > 100% in some ΛCDM estimates) to ordinary starburst levels (~25%). The galaxies aren't impossible. The clock was wrong.
At z = 13: 330 Myr (ΛCDM) → 633 Myr (ISST). +92% extra time, no fitting.
| Redshift | Object | ΛCDM time | ISST time | Extra |
|---|---|---|---|---|
| 10.6 | GN-z11 | 434 Myr | 822 Myr | +89% |
| 13.2 | JADES-GS-z13-0 | 320 Myr | 620 Myr | +94% |
| 14.3 | JADES-GS-z14-0 | 286 Myr | 557 Myr | +95% |
Show the maths
ISST cosmic-age integration
The age at redshift z is the integral of the inverse Hubble rate from there to today:
t(z) \\;=\\; \\int_z^\\infty \\frac{dz'}{(1+z')\\, H_{\\text{ISST}}(z')}H_ISST(z) is the committed dressed expansion history derived from the Wiltshire void/wall lapse contrast on the bare ISST background — closure conditions and present-day H₀ ≈ 62 km/s/Mpc are set by supernova fitting, not by JWST. Evaluated at z = 13 the integral returns 633 Myr; at z = 14.3, 557 Myr.