# Redshift of the Cosmic Microwave Background: increasing or decreasing?

$$\dot z\equiv\frac{\mathrm d z}{\mathrm d t_{\text{obs}}}(t_0)=(1+z)H_0-H(z)$$

The picture and equation above are quoted from Liske et al. (2008).

According to the equation, the redshift of the cosmic microwave background radiation is expected to decrease at this point in time.

However, I think the redshift that will be measured in the future will increase.

Doesn't this equation apply to the cosmic background radiation?

• It is doubtful that mankind will exist for long enough to be able to measure any change in redshift Jul 3 '21 at 11:16
• @Thomas. Yes. If i look at the paper on the wrong concept of cosmology, it says as you say about the way I refer to it. As you said, it seems to be a theory-based prediction, not observation. Jul 3 '21 at 11:39
• @anna v. thanks but It says your link is invalid. The address doesn't show up. Jul 3 '21 at 11:42
• corrected. see this plot to see when CMB starts at en.wikipedia.org/wiki/File:History_of_the_Universe.svg 380.000 years after the big bang Jul 3 '21 at 12:04
• For (doubting) @Thomas: arxiv.org/abs/1907.05151 research.iac.es/proyecto/codex//pages/science-show-cases/… arxiv.org/abs/1907.04495 Detectable within 20 years according to the last of these. Jul 3 '21 at 12:10