Galaxies without dark matter halos?

Phillip Helbig---remove CLOTHES to reply
wrote in message ...
In article , greywolf42
writes:

They are 'explained' by the current model of the big bang. However, the
'big bang' is really a set of different theories that include one basic
event: the expansion of the 'cosmic egg.' (Lemaitre, I believe.) "Red
shift" was the foundation of the original theory termed 'big bang'.

There is some serious confusion here. Yes, Lemaitre was the first to
extensively discuss the "cosmic egg". The redshift was predicted
somewhat earlier by de Sitter and for a time the cosmological red****
was known as the "de Sitter effect".

There is no confusion at all.

We agree that the big bang is essentially the theory that the universe
expanded from a hotter, denser state---the cosmic egg, if you like.

That is the commonality between the various theories that are often lumped
together as the 'big bang.'


This
was renovated by adjusting contants to match observed light elements
(big
bang, version 2.0). This was later upgraded to BB 3.0: CMBR.

There is nothing 'wrong' with ad hoc adjustments of a theory. But such
'observations' are not substantive support for a theory -- as they've
been
put in 'by hand' to match the observations, after the fact. For this
reason, prediction is preferred to ad hoc adjustment.

You have it backwards. The CMBR was PREDICTED (by Gamow in 1948 or so)
long before it was observed (Penzias and Wilson, 1965 or so).

Flatly untrue, though commonly believed. This is one of the myths of
science. See the thread "Gamow's CMBR 'prediction' claims finally put to
rest?" on the following thread:
http://groups.google.com/groups?selm...0nntp2.onemain.
com

Similarly, predictions of the relative abundances of light elements were
on the record before these were observed.

Your statement contradicts the texts I've seen. Please identify the
specific reference(s) that first predicted the abundances of the light
elements.

It did NOT happen that some
arbitrary values were observed and then the big-bang theory made to fit
them, as if it could be made to fit any values. (Gamow also did some
work on element synthesis.)

Your claim is unsupported, and -- I believe -- incorrect. I await
substantiation of the 'light element' claim.

greywolf42
ubi dubium ibi libertas

In article , greywolf42
writes:

They are 'explained' by the current model of the big bang. However, the
'big bang' is really a set of different theories that include one basic
event: the expansion of the 'cosmic egg.' (Lemaitre, I believe.) "Red
shift" was the foundation of the original theory termed 'big bang'.

There is some serious confusion here. Yes, Lemaitre was the first to
extensively discuss the "cosmic egg". The redshift was predicted
somewhat earlier by de Sitter and for a time the cosmological red****
was known as the "de Sitter effect".

There is no confusion at all.

`"Red shift" was the foundation of the original theory termed 'big
bang'' is what I was referring to as confusion. The cosmological
redshift comes from expansion; there are non-big-bang models (both
within the context of Friedmann-Lemaitre models and outside them) which
have redshift but no big bang.

Flatly untrue, though commonly believed. This is one of the myths of
science. See the thread "Gamow's CMBR 'prediction' claims finally put to
rest?" on the following thread:
http://groups.google.com/groups?selm....onemain .com

In sci.physics.relativity, OK.

Dicke certainly had predicted it and was so confident in his prediction
that he started to look for it, then got scooped (his words) by Penzias
and Wilson.

Your statement contradicts the texts I've seen. Please identify the
specific reference(s) that first predicted the abundances of the light
elements.

Can you please name the "texts you've seen"? If they appear
non-crackpot, I'll dig up the references, otherwise it's a waste of my
time.

In article , greywolf42
writes:

They are 'explained' by the current model of the big bang. However, the
'big bang' is really a set of different theories that include one basic
event: the expansion of the 'cosmic egg.' (Lemaitre, I believe.) "Red
shift" was the foundation of the original theory termed 'big bang'.

There is some serious confusion here. Yes, Lemaitre was the first to
extensively discuss the "cosmic egg". The redshift was predicted
somewhat earlier by de Sitter and for a time the cosmological red****
was known as the "de Sitter effect".

There is no confusion at all.

`"Red shift" was the foundation of the original theory termed 'big
bang'' is what I was referring to as confusion. The cosmological
redshift comes from expansion; there are non-big-bang models (both
within the context of Friedmann-Lemaitre models and outside them) which
have redshift but no big bang.

Flatly untrue, though commonly believed. This is one of the myths of
science. See the thread "Gamow's CMBR 'prediction' claims finally put to
rest?" on the following thread:
http://groups.google.com/groups?selm....onemain .com

In sci.physics.relativity, OK.

Dicke certainly had predicted it and was so confident in his prediction
that he started to look for it, then got scooped (his words) by Penzias
and Wilson.

Your statement contradicts the texts I've seen. Please identify the
specific reference(s) that first predicted the abundances of the light
elements.

Can you please name the "texts you've seen"? If they appear
non-crackpot, I'll dig up the references, otherwise it's a waste of my
time.

Phillip Helbig---remove CLOTHES to reply
wrote in message ...
In article , greywolf42
writes:

There are two sides to the "problem". One is whether inflation is
needed to explain why the universe is (nearly) flat. Coles and Ellis
conclude "...we do not need to invole an additional ad hoc mechanism
to
`explain' this calue. In this sense, \emph{there is no flatness
problem} in a purely classical cosmological model."

Isn't that sort of like declaring victory and pulling out? The whole
point
of the 'flatness problem' is that the universe is not observed to be
nearly
flat. Omega is only .02 to .03.

I think there is some confusion here. Yes, Omega (matter) is 0.3 or so.
If you count galaxies, you count matter.

You count apparent luminosity, not matter. And you convert that apparent
luminosity to absolute luminosity based upon a theory of
distance-vs-redshift. If your theory is wrong, so is your absolute
luminosity. (The absolute-luminosity vs morphology relation is also based
on the assumption of the big bang.) If your absolute luminosity is wrong,
then so is your mass estimate (which may have other errors, as well).

Other observations (CMB) indicate that the universe is flat.

If you start with some versions of the BB theory, yes. The CMB may have
other meanings if you assume different theories.

That implies 0.7 in lambda. OK,
take these values and the value of H, independently found to be 71 from
the CMB and the HST key project (which agrees well with the value from
gravitational-lens time delays), and calculate the age of the universe.

Using what theory? What's the point of assuming an 'age of the universe'
that requires BB, if the point is to determine the BB?

It is somewhat older than the age of the oldest objects we know.

What numbers do you come up with? The 10-15 billion years required by the
(post Hipparcos) Hubble shift is significantly younger than the 18 billion
year old globular clusters.

All is
quite consistent. This "standard model" is also compatible with the m-z
diagram for supernovae.

Only if you assume 'dark energy' as an additional ad hoc assumption.

Where is the problem?

I've listed several, above.

Inflation might have occurred, but it (or some other mechanism) is not
REQUIRED to explain the "extremely improbable" situation of a flat
universe.

How do C&E explain the fact that the universe is *not* observed to be
flat?

See above. They don't have to explain it. They point out that THERE IS
NO REASON TO EXPECT IT TO BE FLAT. Their book is concerned mostly with
measuring Omega (matter). At the time, there was no strong evidence for
a cosmological constant, so they favoured a model with lambda=0,
pointing out even then that lambda=0.7 also fits the data and would be a
viable choice. The universe doesn't have to be flat, but it CAN be
flat, or close to it, as current observations seem to indicate.

I thought that GUTs require omega = 1.0. Are they all wasting their time?

And why did the 'big bang' efforts of 20 years ago all focus on the
necessity of 'flatness.'

The other question is whether Omega + lambda 1 is a problem for
inflation. Of course, if inflation isn't needed, that is a rather
uninteresting question. It seems to me that if inflation occurred,
then
the most likely result would be a very nearly flat universe. Since
that
is what observations seem to be indicating, there is no conflict.

The conflict is that the universe is not observed to be flat. Or
rather,
that the Big Bang theory cannot take us from one observation (omega =
..02 or
..03) to other observations (CMBR, etc). This is the core of the
'problem.'
Merely stating 'we observe the universe *is* flat' simply avoids the
theoretical conflict.

These are two separate questions.

No, they are linked.

We all agree that Omega (matter) is
0.3. BUT WE DON'T KNOW WHAT MOS OF THIS MATTER IS.

Then there's little basis for the agreement, don't you think?

Most astronomers
agree that lambda is 0.7. What lambda "IS" is a separate question.

It's not seperate at all. If you don't know what it 'IS', then you can't
know what the measurement of that unknown is.

Denying that lambda is 0.7 since we don't "understand" lambda is as
absurd as denying that Omega is 0.3 since we don't know what the dark
matter is.

Neither position is 'absurd.' The point is, that if you don't know what X
is made of (on the basis of the fundamental theory), then you know nothing
about X. What you are describing is an ad hoc process (which is valid).
You have a theory (BB) which doesn't match observation -- unless an arbtrary
new term is added with a particular value. This 'saves' the theory from
observation. But until that ad hoc material is actually observed, the
theory stands at odds with observation. And if it can't be disproved (ab
initio), then you don't have a scientific theory.

To summarise: if the present observations

Observations of what, specifically?

See any of a number of papers on "cosmic concordance".

I meant the observations to which *you* were referring. I don't insist on a
complete list. Just a few examples.

It's kind of
like the measurement of Avagadro's number a hundred years ago; more than
any one observation, this proof that atoms are real came mostly from
several independent methods giving the same result.

Actually, atomic theory was fought tooth-and-nail by the positivists.

However, it was 'prediction' (prior to experiment) of the atomic/molecular
theory that paved the way to acceptance. Not ad hoc changes to the theory,
based on a series of unpredicted observations.

hold up and the universe is
found to be very, very near the flat case, then this would be evidence
in favour of inflation.

No, that would be evidence of a problem with the big bang theory.
Inflation
is the ad hoc assumption needed to bridge the gap.

The big-bang theory itself makes not statement about the values of Omega
and lambda.

That depends on which 'Big Bang' theory you refer to when you say "THE"
big-bang theory. "THE" (most popular) BB theory contains inflation. Which
makes statements of the values of omega and lambda.

The
classical flatness problem, that something like inflation is needed to
keep Omega from being 1000000 or 0.00000001, is based on a
misunderstanding of the mathematics of classical cosmology, as Coles
and
Ellis point out.

I don't believe that's the 'classical' flatness problem. I thought the
classical flatness problem is based on the exceedingly short lifetime of
the
universe if omega is significantly different from 1.0.

No. THIS is precisely the misunderstanding that Coles and Ellis discuss
in their book.

So Coles and Ellis do not share the commonly-accepted view that there really
*was* a 'flatness problem.' However, everyone understands what the
'classical flatness problem' *was.* Even if Coles and Ellis believe that
this 'problem' was more 'myth' than 'problem.'

greywolf42
ubi dubium ibi libertas

Phillip Helbig---remove CLOTHES to reply
wrote in message ...
In article , greywolf42
writes:

There are two sides to the "problem". One is whether inflation is
needed to explain why the universe is (nearly) flat. Coles and Ellis
conclude "...we do not need to invole an additional ad hoc mechanism
to
`explain' this calue. In this sense, \emph{there is no flatness
problem} in a purely classical cosmological model."

Isn't that sort of like declaring victory and pulling out? The whole
point
of the 'flatness problem' is that the universe is not observed to be
nearly
flat. Omega is only .02 to .03.

I think there is some confusion here. Yes, Omega (matter) is 0.3 or so.
If you count galaxies, you count matter.

You count apparent luminosity, not matter. And you convert that apparent
luminosity to absolute luminosity based upon a theory of
distance-vs-redshift. If your theory is wrong, so is your absolute
luminosity. (The absolute-luminosity vs morphology relation is also based
on the assumption of the big bang.) If your absolute luminosity is wrong,
then so is your mass estimate (which may have other errors, as well).

Other observations (CMB) indicate that the universe is flat.

If you start with some versions of the BB theory, yes. The CMB may have
other meanings if you assume different theories.

That implies 0.7 in lambda. OK,
take these values and the value of H, independently found to be 71 from
the CMB and the HST key project (which agrees well with the value from
gravitational-lens time delays), and calculate the age of the universe.

Using what theory? What's the point of assuming an 'age of the universe'
that requires BB, if the point is to determine the BB?

It is somewhat older than the age of the oldest objects we know.

What numbers do you come up with? The 10-15 billion years required by the
(post Hipparcos) Hubble shift is significantly younger than the 18 billion
year old globular clusters.

All is
quite consistent. This "standard model" is also compatible with the m-z
diagram for supernovae.

Only if you assume 'dark energy' as an additional ad hoc assumption.

Where is the problem?

I've listed several, above.

Inflation might have occurred, but it (or some other mechanism) is not
REQUIRED to explain the "extremely improbable" situation of a flat
universe.

How do C&E explain the fact that the universe is *not* observed to be
flat?

See above. They don't have to explain it. They point out that THERE IS
NO REASON TO EXPECT IT TO BE FLAT. Their book is concerned mostly with
measuring Omega (matter). At the time, there was no strong evidence for
a cosmological constant, so they favoured a model with lambda=0,
pointing out even then that lambda=0.7 also fits the data and would be a
viable choice. The universe doesn't have to be flat, but it CAN be
flat, or close to it, as current observations seem to indicate.

I thought that GUTs require omega = 1.0. Are they all wasting their time?

And why did the 'big bang' efforts of 20 years ago all focus on the
necessity of 'flatness.'

The other question is whether Omega + lambda 1 is a problem for
inflation. Of course, if inflation isn't needed, that is a rather
uninteresting question. It seems to me that if inflation occurred,
then
the most likely result would be a very nearly flat universe. Since
that
is what observations seem to be indicating, there is no conflict.

The conflict is that the universe is not observed to be flat. Or
rather,
that the Big Bang theory cannot take us from one observation (omega =
..02 or
..03) to other observations (CMBR, etc). This is the core of the
'problem.'
Merely stating 'we observe the universe *is* flat' simply avoids the
theoretical conflict.

These are two separate questions.

No, they are linked.

We all agree that Omega (matter) is
0.3. BUT WE DON'T KNOW WHAT MOS OF THIS MATTER IS.

Then there's little basis for the agreement, don't you think?

Most astronomers
agree that lambda is 0.7. What lambda "IS" is a separate question.

It's not seperate at all. If you don't know what it 'IS', then you can't
know what the measurement of that unknown is.

Denying that lambda is 0.7 since we don't "understand" lambda is as
absurd as denying that Omega is 0.3 since we don't know what the dark
matter is.

Neither position is 'absurd.' The point is, that if you don't know what X
is made of (on the basis of the fundamental theory), then you know nothing
about X. What you are describing is an ad hoc process (which is valid).
You have a theory (BB) which doesn't match observation -- unless an arbtrary
new term is added with a particular value. This 'saves' the theory from
observation. But until that ad hoc material is actually observed, the
theory stands at odds with observation. And if it can't be disproved (ab
initio), then you don't have a scientific theory.

To summarise: if the present observations

Observations of what, specifically?

See any of a number of papers on "cosmic concordance".

I meant the observations to which *you* were referring. I don't insist on a
complete list. Just a few examples.

It's kind of
like the measurement of Avagadro's number a hundred years ago; more than
any one observation, this proof that atoms are real came mostly from
several independent methods giving the same result.

Actually, atomic theory was fought tooth-and-nail by the positivists.

However, it was 'prediction' (prior to experiment) of the atomic/molecular
theory that paved the way to acceptance. Not ad hoc changes to the theory,
based on a series of unpredicted observations.

hold up and the universe is
found to be very, very near the flat case, then this would be evidence
in favour of inflation.

No, that would be evidence of a problem with the big bang theory.
Inflation
is the ad hoc assumption needed to bridge the gap.

The big-bang theory itself makes not statement about the values of Omega
and lambda.

That depends on which 'Big Bang' theory you refer to when you say "THE"
big-bang theory. "THE" (most popular) BB theory contains inflation. Which
makes statements of the values of omega and lambda.

The
classical flatness problem, that something like inflation is needed to
keep Omega from being 1000000 or 0.00000001, is based on a
misunderstanding of the mathematics of classical cosmology, as Coles
and
Ellis point out.

I don't believe that's the 'classical' flatness problem. I thought the
classical flatness problem is based on the exceedingly short lifetime of
the
universe if omega is significantly different from 1.0.

No. THIS is precisely the misunderstanding that Coles and Ellis discuss
in their book.

So Coles and Ellis do not share the commonly-accepted view that there really
*was* a 'flatness problem.' However, everyone understands what the
'classical flatness problem' *was.* Even if Coles and Ellis believe that
this 'problem' was more 'myth' than 'problem.'

greywolf42
ubi dubium ibi libertas

In article , greywolf42
writes:

I think there is some confusion here. Yes, Omega (matter) is 0.3 or so.
If you count galaxies, you count matter.

You count apparent luminosity, not matter. And you convert that apparent
luminosity to absolute luminosity based upon a theory of
distance-vs-redshift. If your theory is wrong, so is your absolute
luminosity. (The absolute-luminosity vs morphology relation is also based
on the assumption of the big bang.) If your absolute luminosity is wrong,
then so is your mass estimate (which may have other errors, as well).

No. Estimating the density by measuring luminosity and assuming a
mass-to-light ratio (such as that of our galaxy), also known as Oort's
method, takes place in the LOCAL universe. Redshift-based distances
don't play much of a role here. (The fact that one gets the same result
as with more global methods is another argument in favour of the
(current, but probably relatively robust) standard model.)

Other observations (CMB) indicate that the universe is flat.

If you start with some versions of the BB theory, yes. The CMB may have
other meanings if you assume different theories.

Yes, the heavens could be full of angels with flashlights emitting
microwaves.

That implies 0.7 in lambda. OK,
take these values and the value of H, independently found to be 71 from
the CMB and the HST key project (which agrees well with the value from
gravitational-lens time delays), and calculate the age of the universe.

Using what theory? What's the point of assuming an 'age of the universe'
that requires BB, if the point is to determine the BB?

The point, here, was to show that all is consistent. If I have a theory
in which different lines of investigation lead to the same result within
that theory, without inserting this result from the start, then that is
an argument in favour of that theory.

It is somewhat older than the age of the oldest objects we know.

What numbers do you come up with? The 10-15 billion years required by the
(post Hipparcos) Hubble shift is significantly younger than the 18 billion
year old globular clusters.

This estimate for globular-cluster ages is obsolete. What's your
reference?

All is
quite consistent. This "standard model" is also compatible with the m-z
diagram for supernovae.

Only if you assume 'dark energy' as an additional ad hoc assumption.

It's not an assumption, it's an observation.

Suppose someone gives me a paper bag, and I don't know if it is full of
air or lead. If it feels heavy, I can say that there is something
inside other than air, even if I don't know what it is.

"Dark energy" is just a modern sexy name for the cosmological constant
(with the possibility that the equation of state is perhaps different
than that of a pure cosmological constant). You make it sound like ANY
observed m-z diagram could be made compatible with the data. This is
not true. (In addition, it looks like the equation of state is that of
a pure cosmological constant.)

See above. They don't have to explain it. They point out that THERE IS
NO REASON TO EXPECT IT TO BE FLAT. Their book is concerned mostly with
measuring Omega (matter). At the time, there was no strong evidence for
a cosmological constant, so they favoured a model with lambda=0,
pointing out even then that lambda=0.7 also fits the data and would be a
viable choice. The universe doesn't have to be flat, but it CAN be
flat, or close to it, as current observations seem to indicate.

I thought that GUTs require omega = 1.0. Are they all wasting their time?

Are you taking it as an established fact that GUTs are true---in
contrast to the big bang? Give me some evidence that I should believe
that a GUT---in particular, one requiring omega = 1.0---is true.

And why did the 'big bang' efforts of 20 years ago all focus on the
necessity of 'flatness.'

Because it was perceived to be a problem. That's why Coles and Ellis
wrote their book, to set the record straight.

We all agree that Omega (matter) is
0.3. BUT WE DON'T KNOW WHAT MOS OF THIS MATTER IS.

Then there's little basis for the agreement, don't you think?

No. If the lights go out, we all agree that it is dark, though we might
not know the cause, and our best guesses might disagree.

Most astronomers
agree that lambda is 0.7. What lambda "IS" is a separate question.

It's not seperate at all. If you don't know what it 'IS', then you can't
know what the measurement of that unknown is.

Rubbish. If I weigh a container, I know its weight, even if I don't
know what is inside.

See any of a number of papers on "cosmic concordance".

I meant the observations to which *you* were referring. I don't insist on a
complete list. Just a few examples.

Those ARE the observations to which I am referring.

It's kind of
like the measurement of Avagadro's number a hundred years ago; more than
any one observation, this proof that atoms are real came mostly from
several independent methods giving the same result.

Actually, atomic theory was fought tooth-and-nail by the positivists.

And they lost.

That depends on which 'Big Bang' theory you refer to when you say "THE"
big-bang theory. "THE" (most popular) BB theory contains inflation. Which
makes statements of the values of omega and lambda.

At most, it would claim that the sum is 1. However, even if it is ruled
out, the evidence for the big bang still stands.

So Coles and Ellis do not share the commonly-accepted view that there really
*was* a 'flatness problem.' However, everyone understands what the
'classical flatness problem' *was.* Even if Coles and Ellis believe that
this 'problem' was more 'myth' than 'problem.'

It is no longer "commonly accepted" except among those who have not
followed the progress of science in this field.

In article , greywolf42
writes:

I think there is some confusion here. Yes, Omega (matter) is 0.3 or so.
If you count galaxies, you count matter.

You count apparent luminosity, not matter. And you convert that apparent
luminosity to absolute luminosity based upon a theory of
distance-vs-redshift. If your theory is wrong, so is your absolute
luminosity. (The absolute-luminosity vs morphology relation is also based
on the assumption of the big bang.) If your absolute luminosity is wrong,
then so is your mass estimate (which may have other errors, as well).

No. Estimating the density by measuring luminosity and assuming a
mass-to-light ratio (such as that of our galaxy), also known as Oort's
method, takes place in the LOCAL universe. Redshift-based distances
don't play much of a role here. (The fact that one gets the same result
as with more global methods is another argument in favour of the
(current, but probably relatively robust) standard model.)

Other observations (CMB) indicate that the universe is flat.

If you start with some versions of the BB theory, yes. The CMB may have
other meanings if you assume different theories.

Yes, the heavens could be full of angels with flashlights emitting
microwaves.

That implies 0.7 in lambda. OK,
take these values and the value of H, independently found to be 71 from
the CMB and the HST key project (which agrees well with the value from
gravitational-lens time delays), and calculate the age of the universe.

Using what theory? What's the point of assuming an 'age of the universe'
that requires BB, if the point is to determine the BB?

The point, here, was to show that all is consistent. If I have a theory
in which different lines of investigation lead to the same result within
that theory, without inserting this result from the start, then that is
an argument in favour of that theory.

It is somewhat older than the age of the oldest objects we know.

What numbers do you come up with? The 10-15 billion years required by the
(post Hipparcos) Hubble shift is significantly younger than the 18 billion
year old globular clusters.

This estimate for globular-cluster ages is obsolete. What's your
reference?

All is
quite consistent. This "standard model" is also compatible with the m-z
diagram for supernovae.

Only if you assume 'dark energy' as an additional ad hoc assumption.

It's not an assumption, it's an observation.

Suppose someone gives me a paper bag, and I don't know if it is full of
air or lead. If it feels heavy, I can say that there is something
inside other than air, even if I don't know what it is.

"Dark energy" is just a modern sexy name for the cosmological constant
(with the possibility that the equation of state is perhaps different
than that of a pure cosmological constant). You make it sound like ANY
observed m-z diagram could be made compatible with the data. This is
not true. (In addition, it looks like the equation of state is that of
a pure cosmological constant.)

See above. They don't have to explain it. They point out that THERE IS
NO REASON TO EXPECT IT TO BE FLAT. Their book is concerned mostly with
measuring Omega (matter). At the time, there was no strong evidence for
a cosmological constant, so they favoured a model with lambda=0,
pointing out even then that lambda=0.7 also fits the data and would be a
viable choice. The universe doesn't have to be flat, but it CAN be
flat, or close to it, as current observations seem to indicate.

I thought that GUTs require omega = 1.0. Are they all wasting their time?

Are you taking it as an established fact that GUTs are true---in
contrast to the big bang? Give me some evidence that I should believe
that a GUT---in particular, one requiring omega = 1.0---is true.

And why did the 'big bang' efforts of 20 years ago all focus on the
necessity of 'flatness.'

Because it was perceived to be a problem. That's why Coles and Ellis
wrote their book, to set the record straight.

We all agree that Omega (matter) is
0.3. BUT WE DON'T KNOW WHAT MOS OF THIS MATTER IS.

Then there's little basis for the agreement, don't you think?

No. If the lights go out, we all agree that it is dark, though we might
not know the cause, and our best guesses might disagree.

Most astronomers
agree that lambda is 0.7. What lambda "IS" is a separate question.

It's not seperate at all. If you don't know what it 'IS', then you can't
know what the measurement of that unknown is.

Rubbish. If I weigh a container, I know its weight, even if I don't
know what is inside.

See any of a number of papers on "cosmic concordance".

I meant the observations to which *you* were referring. I don't insist on a
complete list. Just a few examples.

Those ARE the observations to which I am referring.

It's kind of
like the measurement of Avagadro's number a hundred years ago; more than
any one observation, this proof that atoms are real came mostly from
several independent methods giving the same result.

Actually, atomic theory was fought tooth-and-nail by the positivists.

And they lost.

That depends on which 'Big Bang' theory you refer to when you say "THE"
big-bang theory. "THE" (most popular) BB theory contains inflation. Which
makes statements of the values of omega and lambda.

At most, it would claim that the sum is 1. However, even if it is ruled
out, the evidence for the big bang still stands.

So Coles and Ellis do not share the commonly-accepted view that there really
*was* a 'flatness problem.' However, everyone understands what the
'classical flatness problem' *was.* Even if Coles and Ellis believe that
this 'problem' was more 'myth' than 'problem.'

It is no longer "commonly accepted" except among those who have not
followed the progress of science in this field.

In article , greywolf42
writes:

I thought that GUTs require omega = 1.0. Are they all wasting their
time?

No GUT ever required Omega_matter = 1 in any meaningful sense. (As I
said before, at most one could argue that inflation---which might be the
consequence of some GUT---could point to Omega_matter + lambda = 1.)

What used to happen is that the GUT guys would come up with their
particle du jour and suggest it as a dark matter candidate, suggesting
that its predicted mass would be about right to explain the "missing
mass", or even make Omega_matter = 1. (Of course, my feeling is that
they looked up the answer in the back of the book to get the numbers to
come out right.) This is brilliantly described he

http://www.astro.umd.edu/~ssm/mond/flowchart.html

Ten years ago, I was as critical of the confidence of many cosmologists
in the then standard model as greywolf is at present. I'm not critical
as a matter of course, but only when I think something is wrong. My own
view is that, in the last 10 years, driven primarily by data but also by
arguments such as those of Coles and Ellis, the amount of dogma has
decreased and, partly as a result, the current standard model looks
quite promising. Again, the difference is that today's standard model
is driven primarily by data, while 10 years ago the then standard model
was driven primarily by theoretical prejudice.

In article , greywolf42
writes:

I thought that GUTs require omega = 1.0. Are they all wasting their
time?

No GUT ever required Omega_matter = 1 in any meaningful sense. (As I
said before, at most one could argue that inflation---which might be the
consequence of some GUT---could point to Omega_matter + lambda = 1.)

What used to happen is that the GUT guys would come up with their
particle du jour and suggest it as a dark matter candidate, suggesting
that its predicted mass would be about right to explain the "missing
mass", or even make Omega_matter = 1. (Of course, my feeling is that
they looked up the answer in the back of the book to get the numbers to
come out right.) This is brilliantly described he

http://www.astro.umd.edu/~ssm/mond/flowchart.html

Ten years ago, I was as critical of the confidence of many cosmologists
in the then standard model as greywolf is at present. I'm not critical
as a matter of course, but only when I think something is wrong. My own
view is that, in the last 10 years, driven primarily by data but also by
arguments such as those of Coles and Ellis, the amount of dogma has
decreased and, partly as a result, the current standard model looks
quite promising. Again, the difference is that today's standard model
is driven primarily by data, while 10 years ago the then standard model
was driven primarily by theoretical prejudice.

Phillip Helbig---remove CLOTHES to reply
wrote in message ...
In article , greywolf42
writes:

I think there is some confusion here. Yes, Omega (matter) is 0.3 or
so.
If you count galaxies, you count matter.

You count apparent luminosity, not matter. And you convert that
apparent
luminosity to absolute luminosity based upon a theory of
distance-vs-redshift. If your theory is wrong, so is your absolute
luminosity. (The absolute-luminosity vs morphology relation is also
based
on the assumption of the big bang.) If your absolute luminosity is
wrong,
then so is your mass estimate (which may have other errors, as well).

No. Estimating the density by measuring luminosity

One cannot 'measure luminosity.' It's simply not possible without first
making several assumptions. We *can* measure 'brightness' or 'apparent
luminosity.' To measure 'luminosity' (which for your uses means 'absolute
luminosity'), one must first determine the distance and net extinction of
the source. This requires at least two theoretical models.

and assuming a
mass-to-light ratio (such as that of our galaxy), also known as Oort's
method, takes place in the LOCAL universe.

I'm not discussing multiple-universe theories. "Local" in true
distance-measuring systems only extends to 300 light-years or so (after
Hipparcos). Beyond that, we make theoretical assumptions.

Redshift-based distances don't play much of a role here.

You are incorrect. There are about a couple of dozen galaxies where we have
the ability to resolve Cepheid variables -- which are our only reliable
distance "standard candles" (pre-supernovae -- which is another bag of
worms). All distances to other galaxies are measured by assuming the BB and
Hubble constant.

(The fact that one gets the same result
as with more global methods is another argument in favour of the
(current, but probably relatively robust) standard model.)

What are the 'more global methods' to which you refer?

Other observations (CMB) indicate that the universe is flat.

If you start with some versions of the BB theory, yes. The CMB may have
other meanings if you assume different theories.

Yes, the heavens could be full of angels with flashlights emitting
microwaves.

The point is that CMB measurements only indicate 'flatness' for the BB. No
matter how you denigrate competing theories.

That implies 0.7 in lambda. OK,
take these values and the value of H, independently found to be 71
from
the CMB and the HST key project (which agrees well with the value from
gravitational-lens time delays), and calculate the age of the
universe.

Using what theory? What's the point of assuming an 'age of the
universe'
that requires BB, if the point is to determine the BB?

The point, here, was to show that all is consistent. If I have a theory
in which different lines of investigation lead to the same result within
that theory, without inserting this result from the start, then that is
an argument in favour of that theory.

True. However, there are no 'independent' lines of investigation here. If
the BB theory is incorrect, then the masses used are incorrect. And the
'dark matter' amounts are incorrect. And the 'dark energy' amounts are
incorrect. Historically, every one of these 'new' additions to the theory
are ad hoc -- to avoid another 'problem' with the BB.

It is somewhat older than the age of the oldest objects we know.

What numbers do you come up with? The 10-15 billion years required by
the
(post Hipparcos) Hubble shift is significantly younger than the 18
billion
year old globular clusters.

This estimate for globular-cluster ages is obsolete. What's your
reference?

It is not sufficient merely to claim an observation is 'obsolete,' and then
avoid my question entirely.

Again, what specific numbers to you come up with for age of the universe and
age of globular clusters?

All is
quite consistent. This "standard model" is also compatible with the
m-z
diagram for supernovae.

Only if you assume 'dark energy' as an additional ad hoc assumption.

It's not an assumption, it's an observation.

"Dark Energy" may not be observed. The observation is that the Hubble
constant is not linear at far distances. "Dark Energy" is the ad hoc
rationale to account for the observation (the new epicycle).

Suppose someone gives me a paper bag, and I don't know if it is full of
air or lead. If it feels heavy, I can say that there is something
inside other than air, even if I don't know what it is.

Who said that it only held air or lead? 10 pounds of air is the same as 10
pounds of lead. Or a microgram of air and a microgram of lead.

"Dark energy" is just a modern sexy name for the cosmological constant
(with the possibility that the equation of state is perhaps different
than that of a pure cosmological constant). You make it sound like ANY
observed m-z diagram could be made compatible with the data. This is
not true.

No need to distort my position with a strawman argument. I simply note that
the "amount" and 'characteristics' of "dark energy" are backfit to the
observed m-z diagram.

(In addition, it looks like the equation of state is that of
a pure cosmological constant.)

Equations of state are theoretical constructs. The observation is simply
that the "Hubble constant," isn't constant.

See above. They don't have to explain it. They point out that THERE
IS
NO REASON TO EXPECT IT TO BE FLAT. Their book is concerned mostly
with
measuring Omega (matter). At the time, there was no strong evidence
for
a cosmological constant, so they favoured a model with lambda=0,
pointing out even then that lambda=0.7 also fits the data and would be
a
viable choice. The universe doesn't have to be flat, but it CAN be
flat, or close to it, as current observations seem to indicate.

I thought that GUTs require omega = 1.0. Are they all wasting their
time?

Are you taking it as an established fact that GUTs are true---in
contrast to the big bang? Give me some evidence that I should believe
that a GUT---in particular, one requiring omega = 1.0---is true.

Another strawman argument. No, I'm not assuming GUTs are true. But they
are popular. Frankly, since the all predicted the decay of the proton --
and protons have not been seen to decay -- I conclude that GUTs are false.
(Someday I may be proved wrong. But after three major theoretical
'revisions' to get out from under observation, I'm not holding my breath.)

And why did the 'big bang' efforts of 20 years ago all focus on the
necessity of 'flatness.'

Because it was perceived to be a problem. That's why Coles and Ellis
wrote their book, to set the record straight.

Excellent. Another physics myth torpedoed.

We all agree that Omega (matter) is
0.3. BUT WE DON'T KNOW WHAT MOS OF THIS MATTER IS.

Then there's little basis for the agreement, don't you think?

No. If the lights go out, we all agree that it is dark, though we might
not know the cause, and our best guesses might disagree.

Then there's little basis for the agreement as to the cause of the blackout.
All we know is that there is something wrong.

Most astronomers
agree that lambda is 0.7. What lambda "IS" is a separate question.

It's not seperate at all. If you don't know what it 'IS', then you
can't
know what the measurement of that unknown is.

Rubbish. If I weigh a container, I know its weight, even if I don't
know what is inside.

If you don't agree on the theory used to 'weigh' the container, you don't
even know that much.

See any of a number of papers on "cosmic concordance".

I meant the observations to which *you* were referring. I don't insist
on a
complete list. Just a few examples.

Those ARE the observations to which I am referring.

*What* are the observations to which you are referring, specifically?

It's kind of
like the measurement of Avagadro's number a hundred years ago; more
than
any one observation, this proof that atoms are real came mostly from
several independent methods giving the same result.

Actually, atomic theory was fought tooth-and-nail by the positivists.

And they lost.

And yet "modern physicists" continued to apply the positivistic method.
Equations are all.

That depends on which 'Big Bang' theory you refer to when you say "THE"
big-bang theory. "THE" (most popular) BB theory contains inflation.
Which
makes statements of the values of omega and lambda.

At most, it would claim that the sum is 1. However, even if it is ruled
out, the evidence for the big bang still stands.

To which specific 'Big Bang' theory(ies) are you referring?

So Coles and Ellis do not share the commonly-accepted view that there
really
*was* a 'flatness problem.' However, everyone understands what the
'classical flatness problem' *was.* Even if Coles and Ellis believe
that
this 'problem' was more 'myth' than 'problem.'

It is no longer "commonly accepted" except among those who have not
followed the progress of science in this field.

But you still understand what the perceived problem was. Hence, there is no
need to imply that there never was a perception of the problem. And no need
to denigrate others for addressing the 'problem.'

greywolf42
ubi dubium ibi libertas