Summary
The existence and properties of the CMB directly contradict steady-state cosmological models, which posit an eternal universe with constant large-scale properties.
Observation / Fact
Steady-state theory predicts no universal thermal background. The observed CMB, with its precise blackbody spectrum and isotropy, has no mechanism within steady-state frameworks.
Why This Is Non-Trivial
Alternative explanations proposed by steady-state proponents failed to reproduce the spectrum, uniformity, and anisotropy simultaneously. These failures accumulated across decades of observation.
What It Implies
The CMB decisively favors cosmologies with a hot, dense origin and temporal evolution. Past-eternal models lacking such a phase are empirically untenable.
Related
- Discovery of the CMB
- Past-Eternal Models