jacob navia wrote:

OK, so your scenario is

t=0 Start of collision with non moving dust/gas
cloud, galaxy speed 600 Km/sec

t= 10^8 Million years. Galaxy loses all the dust
and material to form new stars, that stays behind
separating from the galaxy at 300Km /sec.

Supposing that the collision (t=0) is 1 000 mill
years after the BB, we have 900 million years
left.

Well, no, whether consciously or not, you're still
manipulating the data to make things come out the
way you want.

If you are asking: "does the existence of 'red
galaxies' at BB + 2Gyears discredit BBT", you
have to be asking "can they happen _at all_ by any
mechanism consistent with BBT". Pushing the starting
point of the dust cleanout to BB + 1Gyears for no
particular reason is biasing the "yes/no" answer for
no particular reason. You don't get to do that.

You want to take the earliest possible time for a
galaxy to exist, assume, on statistical arguments,
that it has an extremal speed, run it through one or
the other "scraper" to denude it of dust and gas,
and ask "how early can that possibly happen"; before
deciding whether there should still be lots of
midsequence stars around to add their color to the
average light seen.

For one thing, a "partial scraper" operating at the
_same time_ as the stars were forming might have
biased them almost all to be small ones.

Essentially, in another scenario, all you need is
some unknown mechanism to make the vortices in the
consolidating stardust closer spaced and smaller;
I'm guessing there are many possible sources of
turbulance in the early universe; proximity to a
quasar might be one such.

True, huge stars and many blue stars live only a
few million years, OK, so after 900 Mill years
most of them disappear. The galaxy loses its blue
component in its spectra. Main sequence stars are
not affected at all, and bright stars (those that
live at least 1 Bill years) are not affected at
all.

My point is that only 900 Mill years after the
crash, most bright stars (stars slightly larger
than the sun, but still in the main sequence)
should be around, and the total looks of the
galaxy should not be so red as observed.

Well, except, again, that you've ripped an
additional 1Gyear off that 0.9 Gyear without any
explicit justification, and that's time to dim down
a bunch more stars.

Anyway, we can dispute that part until the moderator
grows bored with the discussion, but the larger
issue is that the universe is _complicated_, and
trying to use events occurring 2Gyears after the
big bang to discredit the big bang is a pretty dicey
approach. There's just too much time for catenations
of post-BB events we don't understand yet to have
mucked with the data, to claim that data from that
late in time is still clean enough for a backward
look that contradicts the plentiful much earlier
pro-BBT data we _do_ have. The cosmic background
radiation itself, even, IIUC, is a limited view only
back to that 300,000 (or whatever) years after the
event, when the universe first became transparent.

There's still time even by then for lots to have
happened that we don't understand as well as we
understand that the BB happened at all, to have
mucked about with the data _we_ get to see.

Pretty much, I think, you're forced, in looking at
the consolidated matter of the later universe, to
concede the BB, and get on with the task of trying
to understand all the googleplexes of unlikely
things that have occurred forever after that point,
and to trying to winkle out what _they_ were, and
why _they_ have had the effects they've had on what
we see.

Trying to argue against the big bang right now is
like trying to argue against evolution; the other
team has all the data on its side.

xanthian.