https://bigthink.com/starts-with-a-bang/universe-13-8-or-26-7-billion-years/
Tired light theory requires:
- Distant galaxies to be blurry (they aren’t)
- Events in faraway galaxies to happen at the same pace as nearby events (they don’t. Time is dialated just like frequency is redshifted)
- Cosmic background radiation would not be a black body
- Constants c, G, and hbar would change through the history of the universe.