Star age Measurements

On May 19, 4:58*pm, "Mike Dworetsky"
wrote:
oriel36 wrote:
On May 19, 9:40 am, "Mike Dworetsky"
wrote:

I suggest that you stop speculating and read a basic text book on
astronomy first. You will find far more detailed explanations of
stellar evolution and the history of the solar system there.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Ah Mike,you haven't been keeping up with the latest news have
you ?.Stellar evolutionary processes have become far more interesting
lately and one of the few bright spots.no pun intended, amid the chaos
of empirical assertions is that stellar evolution may not be a simple
and single process from beginning to end and especially supernova
events.

99.99% (or more) of stars do not undergo a supernova explosion, as they are
not massive enough.



There were no textbooks a decade ago describing the possibility that
supernova are a transition phase which give rise to solar systems
rather than the demise of a star but you could read about it in an
unmoderated Usenet forum and recently it has made its way into wider
circulation even in a vague way but containing the kernel of an idea
about a star surviving a supernova event.

That the progenitor star creates the nebula from which the elements of
a solar system are formed is tempting -

http://d1jqu7g1y74ds1.cloudfront.net...010/02/461.jpg

Can you provide a reference that includes papers in refereed research
literature? *Usenet forums are not the most likely place where new and
exciting research will be published first.


That invariably leads to the temptation to criticize the patronage of
modern peer review insofar as that system is designed to favor the
reputations and salaries of the reviewers rather than anything else
but I will forego any other comment as it is a waste of my valuable
time and energy.

The Usenet forums are the equivalent of the coffee shops of London in
the late 17th century when science was an enterprise based on
reputation and not salary and as I look around these modern coffee
shops where people like to come and work or pass the time away reading
or in conversation,perhaps things have come full circle apart from the
fact that communication is done electronically.I am not an empiricist
so I neither beg approval nor particularly want to pass judgment on
those who filter astronomical and terrestrial observations through
that system ,even retroactively where a lot of damage was done in
assembling a system based on double modeling.

For instance,the system of Copernicus is based on the fact that we are
on a moving Earth and all judgments of solar system structure and the
motions of planets is based on that view as opposed to the double
modeling of Newton who created a hypothetical observer on the Sun to
account for direct motions -

http://apod.nasa.gov/apod/image/0112/JuSa2000_tezel.gif

"For to the earth planetary motions appear sometimes direct, sometimes
stationary, nay, and sometimes retrograde. But from the sun they are
always seen direct,..." Newton

That perspective of Newton would not get past peer review were there
such a rigorous entity in existence when he wrote it and were he
subject to such an assemblage insofar as observed apparent retrogrades
differ between the inner and out planets in terms of cause.

The reason stellar evolution is one of the bright spots of empiricism
is that it concerns itself with evolutionary processes which do not
require interpretative shifts of perspective common to the higher end
of astronomy,unfortunately the empirical community is lacking in the
type of individuals who do not mix up processes with interpretative
astronomy .


Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

In the unhurried atmosphere of a coffee shop I watch as academics
scramble to put a lot of work I have already done in order and most
times make a mess of it but every now and again I do encounter a
decent rendition such as the wandering Sun analemma as an exercise in
Chinese whispers seen in the 'talk' page as 'Historical shift in
meaning of Analemma' -

http://en.wikipedia.org/wiki/Talk:Analemma

It is amazing what individuals can achieve when the motivation is not
money or celebrity but reputation and therein you have your answer as
to why stellar evolution as a processes of immense efficiency and even
beauty has remained a private work for over 23 years and may end up
remaining that way,sadly of course.

On 18/05/2013 15:24, David Levy wrote:
Thanks Mike

You make it sound like a circular argument, but it isn't.

Do you mean that the current star age measurement doesn't depend on the
big bang theory?
If so, then a star age should not be measured based on its metallicities
composition.

It is a shorthand at least for stars since the earliest stars were made
from almost exclusively hydrogen and helium with only traces of metals.

Therefore, how do we currently estimate a star age?

If you can weigh the star in a binary system, know how far away it is
and how bright then you can get an estimate of its age. The theory of
stellar evolution is pretty good these days and is backed up by the
experimental evidence of the H-R diagram.

The age of the Earth had been fairly well established at about 4-4.5
billion years.

I assume that the Science has estimated this age by measuring the solid
ground and rocks at the Earth. in this case a fundamental assumption was
taken - that the Earth was a rocky star from day one. Never the less, if
the Earth was born as a hot star with mixing boiled matter of melting
Lava and hot Gas, then by definition, there might be a sever error in
this age estimation.

No. The way it works is that when a rock solidifies it can no longer
exchange ions with its surroundings and the chemicals are locked in the
rock. Radioactive decay of uranium, potassium, neodymium, strontium and
other isotopic systems allow you to date rocks to the time when they
were last molten or freely able to exchange ions with their environment.

http://www4.nau.edu/insidenau/bumps/...meteorite.html

I am sceptical over their claimed 4 sig fig precision - I know how hard
these measurements are - but they are probably good to 3 digits.

Measuring the isotopic ratios of the stable isotopes to the radiogenic
ones gives you an estimate of the age of the rock. The clocks all agree
and these days they can do it on the tiniest crystals like zircons.

Zircons are so tough that they tend to survive remelts and machines like
the Shrimp at ANU can read them back like peeling an onion.

http://www.anu.edu.au/CSEM/machines/SHRIMP.htm

Hence, for example - if it took the Earth 5 Billion year to cool down
the surface and set the first solid rocks and ground, than by definition
its age is 5 + 4.5 Billion years.
Do you agree?

In principle that could be true, but in practice the oldest pieces of
space rock we have ever observed in the solar system date to 4.55by.

http://www.space.com/5164-oldest-ast...dentified.html

The age of a rock is the last time that it solidified and stopped
exchanging ions with its environment. This can be a real issue in
biological specimens that are preserved in peat bogs. Tending to bias
the age towards being more recent than it really is.

--
Regards,
Martin Brown

Thanks Yousuf

Well, it does, but only indirectly. Everything in the Universe depends on the BBT, but simply as a means to set the upper age limits.

So, the star age measurements is based on the BBT. Therefore, if the science is using the current star age measurements to confirm the BBT then by definition it sounds like circular argument.

If for example an object is found to be older than the BBT's estimate of the age of the Universe, then there must be something wrong with the estimate of the age of the object.

Now, I really got lost. So if an object found to be older than the BBT's estimation than it is Obvious for the science that the problem is with estimation age of the object. Why is it? Why can't we estimate that there might be a problem with the BBT??? Why???

Thanks Mike

The age of the Earth is assumed to be the same as the age of the solar system itself, which has been accurately determined from the consistent upper age limit of meteorites.

There is some question mark about the upper limit of the meteorites. Please see the following:
http://www.universetoday.com/19599/a...#ixzz2TxPSdxPC

"More recent research measured tungsten content in rocks returned from the moon. Tungsten-182 is what you get when hafnium-182 decays. So the scientists measured the ratios of tungsten to hafnium to determine exactly when the moon formed. This is where the number 4.527 billion years (give or take 10 million years). One problem with this technique is that it’s based on the relative age of meteorites used to determine how old the Solar System is. If that research is incorrect, these estimates for the age of the Moon might be incorrect too".

Thanks Martin

Hence, for example - if it took the Earth 5 Billion year to cool down the surface and set the first solid rocks and ground, than by definition its age is 5 + 4.5 Billion years. Do you agree?

In principle that could be true, but in practice the oldest pieces of space rock we have ever observed in the solar system date to 4.55by.

This is a critical issue. The Earth or the moon could be a molten ball on their birthday as follow: "Our planet was probably still mostly a molten ball of rock, and the impact of the Moon did little to change that".
Hence, there is a chance that it took some time for the Erath & the Moon to cool down and set the first solid rocks. Therefore, by adding all the factors, there might be an error in their age estimation...
This might lead us to an error in the age estimation of the solar system and so on.

David Levy wrote:
Thanks Yousuf
Well, it does, but only indirectly. Everything in the Universe
depends on the BBT, but simply as a means to set the upper age
limits.

So, the star age measurements is based on the BBT. Therefore, if the
science is using the current star age measurements to confirm the BBT
then by definition it sounds like circular argument.

No, you misunderstand this. Star ages are based on observations of stars,
and comparisons with the theory of stellar structure and evolution.


If for example an object is found to be older than the BBT's
estimate of the age of the Universe, then there must be something
wrong with the estimate of the age of the object.
Now, I really got lost. So if an object found to be older than the
BBT's estimation than it is Obvious for the science that the problem
is with estimation age of the object. Why is it? Why can't we
estimate that there might be a problem with the BBT??? Why???

Because the error (formal statistical error based on the measurements) for
the Age of the Universe is fairly small, but the formal error for the
estimated age of one extremely old star is fairly large (due to
observational errors, calibration errors, and to estimated errors in the
theory used). Its formal age is slightly greater than the current Age of
the Universe, but the error on this formal value is large enough for it to
be consistent, with a lower bound less than 13.72 BY. It is only if you
think that scientists are using weasel words when they discuss errors that
you might conclude something is seriously wrong. All good scientists try to
do their best to estimate errors correctly.


Thanks Mike

The age of the Earth is assumed to be the same as the age of the
solar system itself, which has been accurately determined from the
consistent upper age limit of meteorites.

There is some question mark about the upper limit of the meteorites.
Please see the following:
http://www.universetoday.com/19599/a...#ixzz2TxPSdxPC

"More recent research measured tungsten content in rocks returned from
the moon. Tungsten-182 is what you get when hafnium-182 decays. So the
scientists measured the ratios of tungsten to hafnium to determine
exactly when the moon formed. This is where the number 4.527 billion
years (give or take 10 million years). One problem with this technique
is that it’s based on the relative age of meteorites used to
determine how old the Solar System is. If that research is incorrect,
these estimates for the age of the Moon might be incorrect too".

Any way you look at this, however, there is no serious dispute about the age
of the oldest meteorites, and the above is only one determination among many
of the age of the Moon, which remains less than the age of the solar system.


Thanks Martin

Hence, for example - if it took the Earth 5 Billion year to cool
down the surface and set the first solid rocks and ground, than by
definition its age is 5 + 4.5 Billion years. Do you agree?

In principle that could be true, but in practice the oldest pieces of
space rock we have ever observed in the solar system date to 4.55by.

This is a critical issue. The Earth or the moon could be a molten ball
on their birthday as follow: "Our planet was probably still mostly a
molten ball of rock, and the impact of the Moon did little to change
that".
Hence, there is a chance that it took some time for the Erath & the
Moon to cool down and set the first solid rocks. Therefore, by adding
all the factors, there might be an error in their age estimation...
This might lead us to an error in the age estimation of the solar
system and so on.

The age of the oldest terrestrial rocks corroborates the age of the solar
system from meteorites (by being less, as expected), but is not used to
determine the solar system age.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On May 22, 7:30*am, "Mike Dworetsky"
wrote:
David Levy wrote:
Thanks Yousuf
*Well, it does, but only indirectly. Everything in the Universe
depends on the BBT, but simply as a means to set the upper age
limits.

So, the star age measurements is based on the BBT. Therefore, if the
science is using the current star age measurements to confirm the BBT
then by definition it sounds like circular argument.

No, you misunderstand this. *Star ages are based on observations of stars,
and comparisons with the theory of stellar structure and evolution.



*If for example an object is found to be older than the BBT's
estimate of the age of the Universe, then there must be something
wrong with the estimate of the age of the object.
Now, I really got lost. So if an object found to be older than the
BBT's estimation than it is Obvious for the science that the problem
is with estimation age of the object. Why is it? Why can't we
estimate that there might be a problem with the BBT??? Why???

Because the error (formal statistical error based on the measurements) for
the Age of the Universe is fairly small, but the formal error for the
estimated age of one extremely old star is fairly large (due to
observational errors, calibration errors, and to estimated errors in the
theory used). *Its formal age is slightly greater than the current Age of
the Universe, but the error on this formal value is large enough for it to
be consistent, with a lower bound less than 13.72 BY. *It is only if you
think that scientists are using weasel words when they discuss errors that
you might conclude something is seriously wrong. *All good scientists try to
do their best to estimate errors correctly.



'Big Bang' indeed !,the idea that you can not only observe the past
but the entire evolutionary timeline of the Universe directly is
pretty much the most repulsive notion ever devised as it is the
antithesis of reasoning itself -people have about as much a chance as
observing the Universal evolutionary timeline directly as they have of
observing their own evolutionary timeline from child to adult directly
and that this 'Big Bang mess is proposed and accepted by the majority
is the real horror story.

People who stand back from it all and survey the idea should feel
sickened because if they don't they haven't understood what
empiricists try to say about time,space,motion and evolution - it is
truly that shocking,dismal and dismaying.

Dear Mike Dworetsky:

On Tuesday, May 21, 2013 11:30:55 PM UTC-7, Mike Dworetsky wrote:
David Levy wrote:

Thanks Yousuf

Well, it does, but only indirectly. Everything in
the Universe depends on the BBT, but simply as a
means to set the upper age limits.

So, the star age measurements is based on the BBT.
Therefore, if the science is using the current star
age measurements to confirm the BBT then by
definition it sounds like circular argument.

No, you misunderstand this. Star ages are based on
observations of stars, and comparisons with the
theory of stellar structure and evolution.

.... assuming they start with pure hydrogen, a resultant of the Big Bang. The "theory" compared against assumes eh star stars with pure hydrogen, and the star's composition is compared to a composition-with-age chart.

If for example an object is found to be older
than the BBT's estimate of the age of the Universe,
then there must be something wrong with the
estimate of the age of the object.

Now, I really got lost. So if an object found to be
older than the BBT's estimation than it is Obvious
for the science that the problem is with estimation
age of the object. Why is it? Why can't we estimate
that there might be a problem with the BBT??? Why???

Because the error (formal statistical error based on
the measurements) for the Age of the Universe is
fairly small, but the formal error for the estimated
age of one extremely old star is fairly large (due to
observational errors, calibration errors, and to
estimated errors in the theory used). Its formal age
is slightly greater than the current Age of the
Universe, but the error on this formal value is large
enough for it to be consistent, with a lower bound
less than 13.72 BY. It is only if you think that
scientists are using weasel words when they discuss
errors that you might conclude something is seriously
wrong. All good scientists try to do their best to
estimate errors correctly.

Excellent response.

....
The age of the Earth is assumed to be the same
as the age of the solar system itself, which has
been accurately determined from the consistent
upper age limit of meteorites.

There is some question mark about the upper limit
of the meteorites. Please see the following:

http://www.universetoday.com/19599/a...#ixzz2TxPSdxPC

"More recent research measured tungsten content
in rocks returned from the moon. Tungsten-182 is
what you get when hafnium-182 decays. So the
scientists measured the ratios of tungsten to
hafnium to determine exactly when the moon formed.
This is where the number 4.527 billion years
(give or take 10 million years). One problem with
this technique is that it's based on the relative
age of meteorites used to determine how old the
Solar System is. If that research is incorrect,
these estimates for the age of the Moon might be
incorrect too".

Any way you look at this, however, there is no
serious dispute about the age of the oldest
meteorites, and the above is only one determination
among many of the age of the Moon, which remains
less than the age of the solar system.

.... and it assumes the Moon was an asteroid capture (essentially), to arrive at an anomaly. Is it still, if it is the result of a Theia collision?

....
Hence, for example - if it took the Earth
5 Billion year to cool down the surface and set
the first solid rocks and ground, than by
definition its age is 5 + 4.5 Billion years. Do
you agree?

In principle that could be true, but in practice
the oldest pieces of space rock we have ever
observed in the solar system date to 4.55by.

This is a critical issue. The Earth or the moon
could be a molten ball on their birthday as
follow: "Our planet was probably still mostly a
molten ball of rock, and the impact of the Moon
did little to change that".

Hence, there is a chance that it took some time
for the Erath & the Moon to cool down and set the
first solid rocks. Therefore, by adding all the
factors, there might be an error in their age
estimation...

This might lead us to an error in the age
estimation of the solar system and so on.

The age of the oldest terrestrial rocks corroborates
the age of the solar system from meteorites (by being
less, as expected), but is not used to determine
the solar system age.

David A. Smith

On 17/05/2013 6:44 PM, David Levy wrote:
So the science is measuring the star age based on the fundamental Idea
of the Big bang.

Not true, as others have written. In any case, the Big Bang is now
so well supported by so many lines of evidence that using it as a
constraint on star ages is justified.

With the results of the star age they are coming back and reconfirm the
Big bang theory.

Star ages, where they can be measured independently, are consistent
with Big Bang theory, but they are not considered significant
evidence in favor of the Big Bang.

The Steady State model, referred to in a later post, is utterly
dead. The distant universe looks completely different from the local
universe, contrary to the basic Steady State prediction. I suppose
the Big Bang model could turn out to be wrong (though whatever
replaces it will have to look a lot like the Big Bang through the
last 10 or so Gyr), but Steady State is out.

In article ,
Yousuf Khan writes:
[Metallicity] only works for roughly comparing & categorizing really old stars
(mainly first and second generation) vs. modern ones (third generation).

All basically correct but perhaps in need of some clarification.
With few exceptions, there is no mechanism for destroying metals once
created. Therefore, on average, metallicity increases with time. In
the Milky Way, there are no young stars with low metallicity because
the gas out of which stars form has long since been "polluted" with
metals. However, location matters, and young stars formed in the
Galactic outskirts can have lower metallicity than old stars formed
nearer the center.

As Yousuf Khan wrote:
[age-metallicity] is not a linear relationship, you don't have
successive generations of stars getting grittier and grittier.

Basically right, but there aren't strict generations; stars are
forming all the time in the Milky Way.

The galaxies aren't getting more metallic,

Metallicity in individual galaxies is increasing with time but at
different rates in different galaxies.

metallicity is hardly the only way to determine the age of a star,

As (I think) Mike and Martin wrote, metallicity is not a measure of
stellar age except in the crudest approximation. In fact, measuring
ages for individual stars is extremely difficult. Measuring ages for
star clusters is somewhat easier, though. The key is to determine
the mass of the most massive main sequence stars in the cluster, then
use stellar evolution theory to determine the main sequence lifetime
for stars at that mass. Because more massive stars have left the
main sequence, that gives the age of the cluster.

For ages of individual stars, you have to know quite a lot of
detailed information. State of the art is the Sun's age via
helioseismology, but that sort of detail isn't available for many
stars. There are rough indicators such as photospheric lithium
abundance (which decreases with age but reaches zero pretty quickly)
and chromospheric activity, but these are mainly relative indicators
for stars that are otherwise similar.

all stars are 3rd generation now, so metallicity is not the only
way to determine a star's age, nor even the best way.

Basically true for most stars. Some stars are "2nd generation"
(referred to as Population II, but the populations go the opposite
way to generations). Pop II stars have lower metallicity than "3rd
generation" (Pop I) stars, but as I wrote above, there is no direct
relation between metallicity and age for either population.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

dlzc wrote:
Dear Mike Dworetsky:

On Tuesday, May 21, 2013 11:30:55 PM UTC-7, Mike Dworetsky wrote:
David Levy wrote:

Thanks Yousuf

Well, it does, but only indirectly. Everything in
the Universe depends on the BBT, but simply as a
means to set the upper age limits.

So, the star age measurements is based on the BBT.
Therefore, if the science is using the current star
age measurements to confirm the BBT then by
definition it sounds like circular argument.

No, you misunderstand this. Star ages are based on
observations of stars, and comparisons with the
theory of stellar structure and evolution.

... assuming they start with pure hydrogen, a resultant of the Big
Bang. The "theory" compared against assumes eh star stars with pure
hydrogen, and the star's composition is compared to a
composition-with-age chart.

You have a false notion of how models are made. Possibly you have some
incorrect notion of stellar evolution.

Not pure hydrogen, but hydrogen and helium, and it is not correct that
models assume no metals. The reason for this is that all stars that can be
observed today have some metals (though there are extreme very old stars
with very low metal content vs the Sun). The metal content affects the
opacity of the gas, which in turn affects the way the stars evolve.

Star compositions are determined directly by spectroscopy.

Various attempts have been made to model the "Population III" stars that
would have been the first to condense from the original gas mixture. There
would have been no dust--because there was no carbon, silicon, etc.
However, these cannot be compared observationally because no such stars have
been found, yet.


If for example an object is found to be older
than the BBT's estimate of the age of the Universe,
then there must be something wrong with the
estimate of the age of the object.

Now, I really got lost. So if an object found to be
older than the BBT's estimation than it is Obvious
for the science that the problem is with estimation
age of the object. Why is it? Why can't we estimate
that there might be a problem with the BBT??? Why???

Because the error (formal statistical error based on
the measurements) for the Age of the Universe is
fairly small, but the formal error for the estimated
age of one extremely old star is fairly large (due to
observational errors, calibration errors, and to
estimated errors in the theory used). Its formal age
is slightly greater than the current Age of the
Universe, but the error on this formal value is large
enough for it to be consistent, with a lower bound
less than 13.72 BY. It is only if you think that
scientists are using weasel words when they discuss
errors that you might conclude something is seriously
wrong. All good scientists try to do their best to
estimate errors correctly.

Excellent response.

...
The age of the Earth is assumed to be the same
as the age of the solar system itself, which has
been accurately determined from the consistent
upper age limit of meteorites.

There is some question mark about the upper limit
of the meteorites. Please see the following:

http://www.universetoday.com/19599/a...#ixzz2TxPSdxPC

"More recent research measured tungsten content
in rocks returned from the moon. Tungsten-182 is
what you get when hafnium-182 decays. So the
scientists measured the ratios of tungsten to
hafnium to determine exactly when the moon formed.
This is where the number 4.527 billion years
(give or take 10 million years). One problem with
this technique is that it's based on the relative
age of meteorites used to determine how old the
Solar System is. If that research is incorrect,
these estimates for the age of the Moon might be
incorrect too".

Any way you look at this, however, there is no
serious dispute about the age of the oldest
meteorites, and the above is only one determination
among many of the age of the Moon, which remains
less than the age of the solar system.

... and it assumes the Moon was an asteroid capture (essentially), to
arrive at an anomaly. Is it still, if it is the result of a Theia
collision?

As far as I am aware, the collision theory is still the leading model for
the formation of the Moon.


...
Hence, for example - if it took the Earth
5 Billion year to cool down the surface and set
the first solid rocks and ground, than by
definition its age is 5 + 4.5 Billion years. Do
you agree?

In principle that could be true, but in practice
the oldest pieces of space rock we have ever
observed in the solar system date to 4.55by.

This is a critical issue. The Earth or the moon
could be a molten ball on their birthday as
follow: "Our planet was probably still mostly a
molten ball of rock, and the impact of the Moon
did little to change that".

Hence, there is a chance that it took some time
for the Erath & the Moon to cool down and set the
first solid rocks. Therefore, by adding all the
factors, there might be an error in their age
estimation...

This might lead us to an error in the age
estimation of the solar system and so on.

The age of the oldest terrestrial rocks corroborates
the age of the solar system from meteorites (by being
less, as expected), but is not used to determine
the solar system age.

David A. Smith

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Dear Mike Dworetsky:

On Thursday, May 23, 2013 12:16:51 AM UTC-7, Mike Dworetsky wrote:
dlzc wrote:
... assuming they start with pure hydrogen, a
resultant of the Big Bang. The "theory" compared
against assumes [the star starts] with pure hydrogen,
and the star's composition is compared to a
composition-with-age chart.

You have a false notion of how models are made.
Possibly you have some incorrect notion of stellar
evolution.

Well, it is a cinch that I cannot type. Hopefully corrected above. You got the gist, which means you are at least as smart as me...

Not pure hydrogen, but hydrogen and helium, and
it is not correct that models assume no metals.

The HR chart you referred to earlier, has a position on it for a star with pure* hydrogen. No? *Please understand that I mean by pure hydrogen, the initial mix the Big Bang is supposed to have produced (and note that this was established by observation of the mix, and not fundamental physics... it was tuned).

The reason for this is that all stars that can be
observed today have some metals (though there are
extreme very old stars with very low metal content
vs the Sun).

To play Devil's advocate, should some form of continuous Bang be going on (or white holes, or evaporating proto black holes), a pure* hydrogen star does not have to be old. For example globular clusters are assumed to be old, because there was a Big Bang, and that was the only time pure* hydrogen was available. Hence the OPs reference to circular argument. They also have been stripped of their dust (see below, and assuming they were the cores of smaller galaxies that lost their "disc stars" to the larger galaxy).

The metal content affects the opacity of the gas,
which in turn affects the way the stars evolve.

Star compositions are determined directly by spectroscopy.

Various attempts have been made to model the
"Population III" stars that would have been
the first to condense from the original gas
mixture. There would have been no dust--because
there was no carbon, silicon, etc.

However, these cannot be compared observationally
because no such stars have been found, yet.

We cannot image individual stars outside the Milky Way. So what we see, are illuminated dust clouds in more distant areas... a sort of shadow play. We cannot see the stars, only what they do to / through dust. So of course we see metallicity. Granted, if there is dust there, it is a good assumption those nearby stars are the source...

....
Any way you look at this, however, there is no
serious dispute about the age of the oldest
meteorites, and the above is only one determination
among many of the age of the Moon, which remains
less than the age of the solar system.

... and it assumes the Moon was an asteroid capture
(essentially), to arrive at an anomaly. Is it still,
if it is the result of a Theia collision?

As far as I am aware, the collision theory is still
the leading model for the formation of the Moon.

I was not challenging this.

The "anomaly" is the assumption that the Moon was a typical asteroid and was captured, not the isotopic age of its constituents as compared to typical asteroids.

So I was trying to talk to the OP about this particular item on his laundry list of anomalies that he has chosen because he thinks they "disprove" the Big Bang theory.

David A. Smith

In article ,
dlzc writes:
*Please understand that I mean by pure hydrogen, the = initial mix
the Big Bang is supposed to have produced (and note that this w= as
established by observation of the mix, and not fundamental
physics...

On the contrary, there are theoretical calculations of the light
nuclide abundances. Do a web search on "Big Bang Nucleosynthesis."
Observations agree with theory. I'm not sure which is considered
more accurate nowadays.

To play Devil's advocate, should some form of continuous Bang be
going on (= or white holes, or evaporating proto black holes),

or invisible fairies (but evaporating black holes would not be adding
to total mass)

a pure* hydrogen star does not have to be old.

Logically correct, but there is no evidence for creation of new
matter. One would have to ask, though, if low-metal stars are
forming now, why don't we see any low-metal gas?

globular clusters are assumed to be old , because there was a Big
Bang, and that was the only time pure* hydrogen was available.

No. As has been written in this thread, globular clusters are
assumed to be old because of their HR diagrams. In particular, the
clusters contain no main sequence stars more massive than a fairly
small value. That's because (in the standard view), all stars with
larger mass have evolved away from the main sequence.

Hence the OPs reference to circular argument

was mistaken.

They also have been stripped of their dust

What makes you think globular clusters ever had dust (though they
probably did)? More relevant, they have been stripped of gas, or the
gas was entirely used up in forming the stars. What that has to do
with anything being discussed here escapes me.

(see below, and assuming they were the cores =
of smaller galaxies that lost their "disc stars" to the larger galaxy).

Globular clusters were the cores of galaxies?! Why would you suggest
that?

We cannot image individual stars outside the Milky Way.

If you mean image the stellar surfaces, that's true. It's only
possible for stars that are both nearby and physically large. If you
mean see a star as separate from other stars in the same galaxy,
that's not entirely true. Bright stars can be resolved in nearby
galaxies and supernovae even in distant galaxies. Cepheid variables,
fore example, are particularly important for distance measurements.

So what we see, are illuminated dust clouds in more distant areas

I have no idea what you mean by this. Galaxies in general are seen
as we see the Milky Way by naked eye: patches of light spread over a
finite area on the sky. The light comes from stars that are not
resolved individually, as Galileo discovered for the Milky Way. Dust
has nothing to do with it (in visible light) except that dust
extinction diminishes the light that would otherwise be seen.
(Reflection from dust is seen in a few rare cases but contributes a
miniscule fraction of the total light.)

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