[Mod. note: please could all posters try to remain polite and focussed
on the scientific issues rather than on scoring points -- mjh]

jacob navia wrote:
wrote:
jacob navia wrote:

How can an old galaxy form and die in only 2
Bill years?

One can envision lots of mechanisms; all it takes
is something to sweep the galaxy clear of dust
and gas from which to create more stars.

A glancing collision with a larger galaxy could
do that.

The "big enough" jet from another galaxy's
massive black hole could perhaps do that, hosing
away the dust but leaving the existing stars.

Flying through a dust-thick extensive
unconsolidated cloud at relativistic relative
velocities could probably do that too; the stars
would bully on through, but the galactic dust
between them would be stopped in its tracks.

Relativistic relative velocities???

Notice that I supplied _three_ mechanisms, and
rather than respond to the grist of any of them,
you wasted your effort jumping on a badly chosen
word. This isn't productive to understanding the
phenomena, at all.

One of the fastest moving galaxies (NGC 1427A ) is
falling into the Fornax cluster at ... 600 Km/sec.
(http://hubblesite.org/newscenter/new...leases/2005/09)

You'd have a lot less misunderstandings if you'd
resist jumping crowingly and unthinkingly on a
misused _word_, and work out the _math_ for
yourself. If a 600 kmps galaxy hits a 0 kps dust
cloud, a good guess would be that the galaxy's
internal dust falls behind at 300 kmps. How long
does it take to sweep such a galaxy clean of dust?

Well, a galaxy is roughly 10^18 km across, if I
haven't lost a decimal, and 300 kmps is roughly
10^10 km/year, so 10^8 years would suffice, only a
tenth of a billion: lots of time to have cleaned out
a galaxy 2 billion years old.

To accelerate *A GALAXY* to relativistic speeds
would require so much energy that I can safely bet
that there will never be an observation of such an
object. Besides, the high speed of the galaxy
should be *noticable* in its spectra, either in an
increased or decreased red/blue shift.

Yada, yada, yada... You're arguing with the hand.

This looks like a desperate explanation. Yes; it
is *possible* but... is it likely?

If you had bothered to work out the math for
yourself using the data _you_ supplied, you'd know
the answer is in the affirmative. This habit of
failing to do your own homework isn't helping you
understand the issues, at all.

Once you stop forming stars, the blue ones die
their quick deaths, and soon only the
longer-lived red ones remain, and the galaxy
looks "old" only because it no longer has any
surviving blue stars to make it look "young".
That is just as should be expected if you take
out the loose dust by _any_ mechanism.

Just 2 Billion years?

A sun-like star lives 10 Billion years. Even if
there weren't any new star formations, sun-like
stars should go on for quite a while. Supposing
this "encounter at relativistic speeds" takes
place 1 Bill years after the bang, we should see a
lot of blue stars 1 Billion years later, not
enough to make the galaxy red.

Give me strength. Go look up the lifetime for blue
stars, please. You are off by factors containing
multiple digits.

There's nothing "contradictory to the big bang
theory" about finding a _few_ anomalous objects.

Sorry but this is *one* from many examples
discovered. Old galaxies with iron in it, galaxy
clusters at 9 Billion years
(http://www.eso.org/outreach/press-re.../pr-04-05.html)
and *many* others.

Yep, but lots of _single_, different, anomalies
aren't an issue; among "billions of billions" of
galaxies, even the most (within reason) unlikely
events have had time to happen "somewhere, once" by
purely statistical arguments based simply on the
huge number of objects the universe contains. It is
when they are happening "everywhere, often" that you
start to worry about your theory.

The universe is plenty big enough for a few
highly unlikely happenings nontheless to have
occurred.

Probably. The point is, the more "unlikely" events
we find, the more unlikely the theory becomes,
that is my point.

No, the more _identical_ unlikely events we find,
the more danger those events present to the theory.

The more detailed our data investigating capability
becomes, the more _kinds of_ *unique* unlikely
events we can pull out of the data, and that means
there are lots more _unique_ anomalies reported with
every sensing device improvement; but that, again,
is merely an expected result.

Worry when some one contradicting _kind of_ anomaly
starts to dominate the findings, not when new kinds
of anomalies arrive with each sensor improvement.
That's exactly why we pay the big bucks for the
better sensors: so we can winkle the strange and
interesting stuff out of the mostly bland data.

I am not saying that this is 100% impossible to
explain with BB theory, just that BB theory
becomes more and more unlikely as more facts are
known.

Think about what you just wrote.

But at some point people just preferred the new
model because it was simpler...

So far as I know, the Big Bang Theory, with
Inflation, remains by far the most parsimoneous
explanation of the universe as we see it today, and
all the statistical flukes in the world aren't
contradicting that impression; numerous statistical
flukes are an _expected finding_ in such a large
data set.

Now, the big problem here is that there isn't any
Galileo around :-)

I think we need more pressingly to bring back
William of Occam.

The more data we find, the more fractal-like the
universe seems, and fractals provide lots of room
for extremal cases.

Finding the anomalous objects to be the _prevalent_
types would certainly be worrisome to the BBT; any
theory which finds mostly exceptions to its
predictions hasn't long to live.

That's exactly my point.

But you fail to do the math, and so miss making your
point; gut arguments don't work well for arguing
where the numbers involved defy correct intuitions.

Assuming a rotation rate identical to the milky
way, it has the time to make only 8 turns a[n]d it
is already dead and old...

Which is completely irrelevant to the issue.

No. Galaxies are flat,

That is not true in general; spiral galaxies are
flat, elliptical galaxies are, surprise, elliptical.

At the distances where a whole galaxy takes up a
couple of pixels on your sensing device, deciding
whether a galaxy is a certain shape is
"interesting", and has to be based on its spectrum,
not its outline in your sensing device.

But in the cases under discussion, the spectral
anomalies are _already_ an issue, and make trusting
spectral analysis to determine really subtle stuff
like "is the spectral spread appropriate for an
elliptical galaxy, or for a spiral one", a dodgy
choice. That's the level of math I'll _happily_
defer to the experts.

and to get flat they have to rotate for some time
to flatten themselves isn't it?

Which is still irrelevant to the issue of why they
are blue light deprived. Most certainly, they don't
have to "flatten" to be galaxies-at-all.

The scopes have arrived at the immediate
neighborhood of the supposed big bang and there
is not the slightest hint of a bang to see.

You mean besides the cosmic microwave background
radiation that already confirms the BBT to
several decimals of precision?

There was a discussion in sci.astro about
"overaveraging" and the whole "wrinkles in the
face of god" story. I remain a sceptic about that.
But yes, there is no alternative explanation to
the cosmic background.

Then why on earth did you make your previous
statement?

The problem is that it could very well be that we
just do not know what the Cosmic Background *is*,
and we see it as we can: as a "BB " relic.

Yep, that's this big problem with science, you get
this raw data, and then you come up with some
"cooked" interpretation of that data. That's where
we get the documents called "PhD theses".

While that interpretation retains good predictive
capability, it remains "the accepted theory". As
soon as it loses that ability, it lands "in the
dustbin of history". Right now, Big Bang theory is
in no danger at all of landing in the dustbin,
however much it annoys some folks religious or
math-deprived intuitive notions.

That _is_ the Big Bang, granted you aren't going
to see it in an optical telescope, which would be
looking among the wrong wavelengths for the Big
Bang in any case.

I am not so stupid to believe we could "see" the
big bang.

And yet you go right on to insist on exactly that:

Of course not. But its immediate neighborhood
should have *some* marks of such a "bang" having
happened relatively shrtly, i.e. 500 Mill years...

You write like you expect to see the Big Bang from
some exterior vantage point. We're inside it, and
the cosmic background microwave radiation is there
to be seen in every direction we look. It precisely
satisfies your need for "some marks".

It helps to remember, too, that the Universe spent a
good while after the Big Bang, being totally opaque.

300,000 years sticks in my mind, and I refuse to
go look it up to confirm that. Astronomy is an
"also interesting" for me, not something that
dominates my intellectual life, so my
willingness to invest time into it is pretty
limited.

Between the point where it changed phase to be
transparent, and the point where gravity had enough
time to work to produce some stars, there's probably
a big bunch of "nothing at all to look at" out
there, so don't expect to be finding the
astronomical equivalent of "fossils of soft bodied
organisms" where there are none.

It's like the hole in the data before 10^-34 seconds
or whatever the figure is; some stuff is plain
impossible ever to "see"; _lack_ of data isn't much
persuasive in favor of _any_ theory.

And, an established theory will find its
inevitable gathering of people that will stick to
it no matter what.

Right. The ones who win are the ones who do their
own homework. Pretending blue stars will last ten
billion years just because yellow ones do, rather
than bothering to look up the right answer, punches
some pretty large holes in your arguments from the
vantage of more clueful observers. That reduces both
any chance _you'll_ understand reality, and any
chance you'll prevail in pressing your version of
"how things went" on those who think _they_ do.

FWIW

xanthian.