“With measurement errors negated, what remains is the real and exciting possibility that we have misunderstood the Universe”
Webb measured 1,000 Cepheid stars in five galaxies out to 130 million light-years and got Hubble’s numbers again. The easy escape for cosmologists was that Hubble’s measurements were off because of crowded starlight and dust. Webb closed that exit. The expansion rate nearby still disagrees with the one Planck reads from the early Universe, and nobody has a model that explains both.