In message , Ralph Hertle
writes
Martin Brown wrote:

[ text omitted ]

Hi Martin,
Do you have a reference for this? I want to be able to give a proper
reference to people who claim that red-shift is due to 'tired light'

Google "Lyman forest" ought to bring something useful up.
Combine it with "tired light" and you may get exactly what you seek.

Martin:

'Tired light' is a term that suits then advocates of the BB; it is a
derogatory term that is intended to place an emotional wet blanket upon
the issue in order to discredit any possible explanation for a physical
cause of the diminution of the energy levels of photons as they
traverse the openness of space.

And "Big Bang" was also a derogatory term used by the main advocate of
old Steady State theories, Sir Fred Hoyle, to pour scorn on the new
upstarts. Observational evidence has long since settled this debate in
favour of hot Big Bang cosmologies and the name, short and simple has
stuck.

Short names like this often stay in use. Tired light - for light that
loses energy and gets tired after long journeys seems like quite a nice
way of describing it to me.

The proper scientific question to ask is, "What happens to light
photons as they traverse the openness of outer space that causes the
diminution of their energy levels?"

Climbing out of a deep gravitational potential well will do it, but
there is no evidence that we have seen any galaxies where that
contribution was dominant or even significant.

The real killer for steady state theories was when radio astronomy came
along and we could see out much further into the universe that the
numbers of faint active radio galaxies increased far too rapidly to be
consistent with any steady state theory. The universe was seen to have
been much more active at earlier times. Deeper and deeper optical fields
from the likes of Hubble now confirm this too.

Seeing the 4K microwave background radiation was a bonus.

You can always cobble together some "just so" explanation for steady
state models that would fit with enough gratuitous tweaking of physics,
but Occam's razor favours the simpler explanation. It may surprise you
to know that Steady State theories are included in most decent cosmology
text books for historical context.

And distance measures using supernovae as standard candles avoid relying
on using redshift to determine distance. Nothing can trump the
observational evidence - nature is the final arbiter.

Regards,
--
Martin Brown