After the big bang, the gas was too hot to form stars. A time must pass
to cool the universe so that the star formation could begin.

In that period of time there shouldn't be any stars, galaxies or
similar.

The length of time that the "dark ages" has been shrinking lately, in
the beginning of the century it was something like 500 My, but now it
has shrunk to 250-300.

As I have calculated in a previous message, a minimum time of 272
million years (z=12) seemed reasonable to me, to cool the stuff to 35.36
K. Note that temperature in star forming cocoons is only 10K. But big
bang proponents could argue from special conditions, whatever, so I
choose 3 times the temperature where stars can form.

Nobody objected to my previous post, so I can assume that there are no
big errors in those calculations.

So, the incompresible time of dark ages is 272 million years, is that
correct?

The discovery of any galaxy at z=11.8 or higher would definitely
disprove the big bang hypothesis. Is that correct?

Because we have a galaxy at z=11 approx. That is why the really
incompresible length of the dark ages becomes important.

If we wait till the universe cools to (say) 15 degrees the observations
contradict theory. We need too much time, so we can move the cursor till
272 million years but not more.

The whole becomes difficult to visualize with a galaxy of 1e9 solar
masses just after 127 My from the first stars.

And the star population of that galaxy should be really weird since no
star is older than 127 My. That time is very short compared to the life
span of normal stars.

OK we could assume that all stars are super-giant stars that last only a
few million years and explode, but then that population should give a
definite signature in the light of that galaxy.

Do we see that?

If we say that (taking the formation and condensation phase into
account) we have a generation after only 5 million years, that makes for
30 generations at most.

But those are secondary considerations. The important thing is to kindly
tell me if that time (262 My) is correct for the length of the dark
ages...

Thanks