<p>Standard cosmological models predicts that the cosmological redshift and the speed of light are wavelength-independent. This result is confirmed observationally e.g. by <a href="https://arxiv.org/abs/1605.09380" rel="noreferrer">Ferreras &amp; Trujillo (2016)</a>, who used $\sim500\,000$ <a href="http://www.sdss.org" rel="noreferrer">SDSS</a> galaxy spectra down to a precision of $\Delta z \sim 10^{-6}$ and $\Delta z \sim 10^{-5}$ for galaxies at $z&lt;0.1$ and $z&gt;0.1$, respectively.</p>

CC BY-SA 3.0
2017-09-08T13:05:17.720Z
Wow, it always amazes me to see the precision to which scientists test things, especially things someone generally takes for granted or assumes to just be true.
zephyr
CC BY-SA 3.0
2017-09-09T07:51:13.840Z
It's a good point, @zephyr. You often hear a statement about science like "It's just theory". But science is, in fact, not just theory. No model is accepted as a theory without substantial observational/experimental evidence.
pela
CC BY-SA 3.0
2017-09-08T08:15:52.823Z
2017-09-08T08:15:52.823Z
pela
<p>Does wavelength play a role in cosmological redshift? Do we see certain wavelengths affected less by expansion or notice any delay in arrival of certain wavelengths?</p>

<p>How accurate are any observations?</p>

<cosmology><expansion><redshift><cosmological-inflation><wavelength>
Does wavelength affect redshift caused by the metric expansion of space?
Zamicol
# Does wavelength affect redshift caused by the metric expansion of space?

(Asked by: username_0 on 2017-09-08)

Does wavelength play a role in cosmological redshift? Do we see certain wavelengths affected less by expansion or notice any delay in arrival of certain wavelengths?

How accurate are any observations?

**Tags:** cosmology, expansion, redshift, cosmological-inflation, wavelength

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## 1 answers

### Answer by username_1 on 2017-09-08. Score: 5 | Accepted answer

Standard cosmological models predicts that the cosmological redshift and the speed of light are wavelength-independent. This result is confirmed observationally e.g. by [Ferreras & Trujillo (2016)](https://arxiv.org/abs/1605.09380), who used $\sim500\,000$ [SDSS](http://www.sdss.org) galaxy spectra down to a precision of $\Delta z \sim 10^{-6}$ and $\Delta z \sim 10^{-5}$ for galaxies at $z<0.1$ and $z>0.1$, respectively.

> **Comments:**
> **username_2**: Wow, it always amazes me to see the precision to which scientists test things, especially things someone generally takes for granted or assumes to just be true.  
> **username_1**: It's a good point, @zephyr. You often hear a statement about science like "It's just theory". But science is, in fact, not just theory. No model is accepted as a theory without substantial observational/experimental evidence.  

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