Starship Asterisk*

Michael Mozina wrote:[snip]

Alfven got all sorts of things "published" related to plasma cosmology theory, and so did his students.

[snip]

Please provide references to at least one such paper*, published in a relevant peer-reviewed journal, which addresses:

a) Olbers' paradox

b) the Hubble z-distance relationship

c) the primordial abundance of light nuclides (H, D, 3He, 4He)

d) the CMB

e) large-scale structure.

*Collectively or separately, or any combo.

Michael Mozina wrote:[snip]

Of course, if harry (or anyone else) comes up with *scientific* answers to the many questions (or any!) about the CLOSED items, then we can discuss those.

It's typically the discussions that lead us to such answers. Why does a topic, particularly something as broad and encompassing and EU theory have to be "closed" at all?

Because

a) no proponent has been able to demonstrate, by reference to papers published in relevant peer-reviewed journals, that this so-called theory can account for any of the key sets of good, *observational* results in cosmology

b) the so-called discussions have avoided this core requirement of any scientific cosmological theory

c) continued 'discussion' seems thus to be simply an excuse for promotion of an idea without demonstrated scientific merit.

Even if it's "dark horse" at this point in time, there is certainly ample evidence of electrical currents in space. It seems to me that some aspects of EU theory have already been incorporated into standard theory. Birkeland currents for instance are well recognized in standard theory. That would also be an integral part of EU theory. The only difference in fact is that EU theory would extend that concept to incorporate intergalactic currents rather than just limit them to flowing *inside* the solar system.

That may be so.

Or it may not.

Despite, apparently, dozens of professional scientists having worked on this for decades, there is nothing to show that such an approach has legs.

If and when such a demonstration is made, you are welcome to present - and discuss - it here.

Until then ...

Did I miss anything significant?

Did you read Alfven's book that I suggested earlier? If not, then I would say "yes", mostly all the math.

Which chapter(s) in this book cover(s):

a) Olbers' paradox

b) the Hubble z-distance relationship

c) the primordial abundance of light nuclides (H, D, 3He, 4He)

d) the CMB

e) large-scale structure (as the term is used in modern astronomy).

Did I not state that this is a scientific forum?

Of course it is, which is why we are all here in the first place. What does that have to do with it?

Or do you not understand how science works, today?

I'm pretty sure I understand the process fairly well at this point.

Sorry; let me try again.

The Night Sky Live forum, a.k.a. The Asterisk*, which includes this Asterisk Cafe, is a scientific forum, devoted to astronomy and related sciences.

And pretty much everything I've discussed here (harry too) has been related to that topic.

The core means by which modern astronomy, as a science, is made public is publication of papers in relevant, peer-reviewed journals.

Science is more than just publishing papers in Journals however. There are books too, and there are unpublished ideas to consider. There are scientific tests to conduct. There are all sorts of aspects of science that little or nothing to do with publishing papers.

Specifically, astronomical theories, hypotheses, observations, etc are available - to working scientists and the general public alike - principally through such papers.

But people like Alfven have written whole books on something like plasma cosmology and cover many of the basic aspects of that theory in some detail. He has even layed out a lot of the math. It's not possible to cover material of that nature in a simply paper, and you'll need to read more than papers if you ever expect to understand plasma cosmology theory. It's really as simple as that.

These are the primary sources.

Says who? Why isn't Alfven's book on plasma physics required reading? Why isn't that a "primary" source if you wish to understand plasma cosmology?

Any questions?

Too many to list, starting with why you think papers are the be-all-end-all of knowledge?

[snip]

If you wish to discuss the primacy of peer-reviewed papers as the vehicle for presenting theories in modern science, how science got to be that way, why it seems to work better than any alternative, and so on, I'd be glad to recommend some appropriate internet discussion fora.

Has anyone been able to demonstrate 'magnetic reconnection' in the laboratory?

If not, perhaps we can lay to rest that premise in the operation of our Sun's behaviour.

kovil wrote:Has anyone been able to demonstrate 'magnetic reconnection' in the laboratory?

If not, perhaps we can lay to rest that premise in the operation of our Sun's behaviour.

Might be a good question ... in another thread (this one is about the origin of the universe, and cosmology in general).

Or maybe you could tell us what importance magnetic reconnection has to Olbers' paradox, the observed abundance of light nuclides, the CMB, the Hubble z-distance relationship, and the observed large-scale structure of the universe ...

This thread is about (observational) cosmology - or at least it's supposed to be.

So what are the key observations, about the universe, that any theory of cosmology should at least claim to address?

Whatever else you might mention, Olbers' paradox has got to be there! And it can be generalised, to cover all wavebands in the electromagnetic spectrum.

What do we see, when we look at the sky?

First, the daytime sky, down here on Earth, is blue. But we know, and have known for a very long time, that that has to do with something very local.

Let's consider only the sky as seen by an observer far above the Earth's atmosphere.

Second, there are lots of 'point sources', in just about every waveband. With a few exceptions*, all such have been determined to be 'stars' or 'galaxies' (I'm summarising, of course, covering only the main points; there's lots of t's to be crossed and i's to be dotted). Fairly well bounded estimates of the distances to these objects can be made [theory warning! the estimated distance DOES depend upon certain choices ... of cosmological principle, of pertinence of relevant physics, etc].

Third, there are lots of 'extended sources', in all wavebands - same story.

Fourth, there is an unresolved, diffuse 'background', in some wavebands - very different story.

In the x-ray band, this diffuse background has now been pretty much accounted for - it is numerous, faint, distant AGNs (we needed better telescopes to work this out; Chandra and XMM-Newton did the trick).

In the EUV (extreme ultraviolet), it's simply continuum emission from hydrogen ... due to the ISM (interstellar medium), so not very interesting, cosmologically speaking.

... and in the microwave waveband, there is a near perfect blackbody diffuse source, across the whole sky; today, this is called the CMB (cosmic microwave background).

There may be a diffuse background in the FIR (far infrared), or NIR ... but if there is, it's very faint.

So, in any cosmological theory, surely we can expect an account of the 'darkness of the night sky' in all wavebands, and of the CMB?

And for the CMB, surely we can expect an account of its near perfect blackbody spectrum?

If a theory claims to have applicability in the cosmological domain, but is mute on the CMB and the generalised Olbers' paradox, surely we can say it can't be a very good theory, can't we?

Next: what else is important, in terms of observational cosmology, and why.

*The nature of many of the EGRET gamma point sources is still unknown, for example.

In Brynjolfsson's 'plasma redshift', interactions between photons and the electrons in various plasmas (solar corona, interplanetary medium, interstellar medium, inter-galactic medium, inter-cluster medium, ...) gives rise to a redshift.

This idea is but one of many that propose such an effect.

And like all its cousins, it is easy - in principle - to test, and several possible tests likely can be done by anyone reading this post*.

The first kind of test is to find a consistent 'plasma redshift' signal in one or more of the huge, freely available sets of consistent, high quality astronomical redshift data, such as SDSS or 2dF. The 'plasma redshift' signal should be easily discernible as a relationship between the observed redshift and the expected (or modelled) integrated electron density along the line of sight to the astronomical object (this is, in Brynjolfsson's 'plasma redshift' idea, expressed in equation (1) in the fifth unpublished paper in the link Michael provided). In fact, Brynjolfsson claims just such a signal can be found in a galactic latitude correlation in just a few hundred 1a SNe, so it should be glaringly obvious in the SDSS or 2dF data (there are hundreds of thousands of galaxy redshifts in these datasets).

The second kind of test involves looking for a frequency dependence in the observed redshifts of at least some kinds of astronomical objects. Unlike doppler, gravitational, or cosmological causes of redshift - in which the observed redshift is the same across the entire electromagnetic spectrum - the observed redshift arising from Brynjolfsson's 'plasma redshift' varies with waveband**. Today, there is a lot of good data on redshifts (and line profiles) of astronomical objects observed in the x-ray, visible (and UV and NIR), microwave, and radio wavebands (there is some in the FIR too). A 'Brynjolfsson plasma redshift signal' should be somewhere in this data, though it may be harder to find than in the first kind of test.

While I don't know if anyone has done the first kind of test, starting with a clearly stated hypothesis, a great many of such tests have, in fact, been already done. For example, in rotation curve observations of nearby galaxies the 'Brynjolfsson plasma redshift signal' would likely be rather obvious (as an 'inclination correlation', perhaps). The fact that no one, apparently, has yet noticed any such signal probably tells us that it isn't there to find.

*Given the amount of data most tests would involve, you'd best have a broadband internet connection.
**I'm not 100% sure of this; the relevant 'theory' parts in Brynjolfsson's papers are hard to follow. Certainly the first Brynjolfsson paper clearly states there is such a relationship (see section 3).

Another cosmologically relevant fact about what we can see ...

Point sources, of the photons astronomers detect, are stars*; stars aggregate into galaxies, globular clusters, etc.

Are the consistent structures bigger than galaxies, visible by their emission of photons? Yes; galaxy groups and clusters.

Bigger than clusters? Yes; super-clusters, voids, sheets, walls, ...

As you go to larger and larger scales, what can we say about how light (and other EM radiation) emitting objects clump/cluster/are distributed?

There are powerful, quantitative ways of describing structure; one is how much randomly sampled regions deviate from the average, in terms of the density of their constituents. So, for example, regions that are ~light-years in size have a huge range of 'constituent densities' - the hearts of globular clusters vs inter-cluster voids, for example.

If you plot some measure of the size of the average density fluctuations against the characteristic scale, what do you find? An amazing thing - the universe gets more and more homogeneous as the scale increases ... on scales of ~100 Mpc and greater, the universe seems very smooth indeed.

This variation in the structure of the visible (all EM) universe by size/scale is now well constrained; in shorthand it is called 'large-scale structure'.

Although it's not as intuitively obvious as Olbers' paradox, it is nonetheless a deep fact about the universe in which we live ... and we can surely expect any cosmological model, or theory, to at least attempt to match this observed distribution.

Next, what else?

*And the AGN of distant galaxies, and ... as in my previous post, I'm simplifying greatly.

Yet another cosmologically relevant fact about what we can see ...

We can estimate the distance between here and most astronomical objects.

For some, the estimate is pretty direct, and pretty accurate - we use trigonometric parallax, and can get a distance estimate accurate to <1% (for stars sufficiently close).

For others, especially very distant objects, getting even +/- 20% distance estimates is still difficult. The 'distance ladder' has been a key endeavour of astronomers for over a century now.

Hubble discovered a curious fact - there seems to be a close relationship between the redshift of galaxies and their distance from us. To be sure, the estimates of distance he made, back in the 1920s, are now known to be off by a factor of several (the relative distances are pretty much unchanged though), but the relationship which bears his name has been confirmed through millions of observations, by thousands of astronomers, in many different wavebands, etc, etc, etc.

As this relationship relates to just about the only objects we can see, over such big distances, it must surely be a leading cosmological fact which all theories claiming to have a cosmological scope must at least attempt to explain.

So now we have:

* Olbers' paradox (in several wavebands)

* the CMB (including its dipole and angular power spectrum) - a subset of Olbers' paradox, if you wish

* large scale structure

* the Hubble relationship.

Anything other key facts (observations) which any scientific theory of cosmology should at least attempt to account for?

Yes, that's next - the primordial abundance of light nuclides.

Unlike the four, previous, key cosmological observations*, this last one - the primordial abundance of light nuclides - involves application of several aspects of modern physics.

First there's the quantum theory underneath the modern understanding of the atom; we need this because (among other things) it is spectroscopy (based on this quantum theory of the atom) which gives us relative abundances of elements (and isotopes) in the material which emits the photons astronomers detect.

Then there's the extent to which the observed abundances, of elements and isotopes, reflects the ('chemical') history of the objects which contain these. Or, the extent to which the material in the objects has been 'processed', in the alchemical sense of turning one element into another.

The relevant science here can get intricate, but the conclusions are pretty robust - material which has not been 'processed' inside stars** is overwhelmingly H and He, and within these two elements, the H, D, 3He, and 4He relative abundances are {insert quantitative statement here}.

Note that this set of statements relates only to matter that we can detect by the photons it emits (or absorbs); if there is matter which does not react with (or to) photons, then that matter is outside these statements.

Fortunately, we already know - in great detail - just how all atoms, molecules, etc interact with photons, so the relative abundance statements describe all 'ordinary' (a.k.a. 'baryonic') matter.

And that's the fifth, and last (for now) cosmological fact relevant to this thread ("Origins of the Universe").

Are there other, cosmological, facts which any scientific theory of cosmology (including the origin of the universe) needs to take account of?

If you know of any, let's hear you!

In the meantime, how well do the various, scientific, cosmological theories do, in terms of accounting for these five sets of facts? You know the answer: there's a class of theories, which goes under the popular title of "Big Bang Theory", that does an exceptionally good job in this regard.

Are there alternatives? Not as far as I know; if you know of any, please tell us! But be sure to check that they a) even attempt to address these five sets of tests, and b) do a reasonable job of accounting for the facts.

*Olbers' paradox is a direct observation - the 'night sky' is dark, except for the CMB. The CMB, as cosmological data, has several levels (its blackbody SED, the dipole, and the angular power spectrum), but they are all directly observable. Large-scale structure and the Hubble relationship rely upon the distance ladder, the nailing down of which is observationally complex, but the cosmological facts are, conceptually, just one step from being directly observable.
**Or in any other astrophysically relevant process, e.g. cosmic ray collisions

You forgot to mention SN Ia lightcurve decline redsift!
BTW first observation of doppler efect was made by Ole Roemer (1644-1710).

nikki wrote:You forgot to mention SN Ia lightcurve decline redsift!

All of what I've written has been but a mere summary of the relevant parts of (observational) cosmology, and so, of necessity, parts have been either overlooked or the shorthand that comprises the summary too brief to cover all aspects.

So it is with the high-z 1a SNe distance-redshift relationship ... it's a subset of the Hubble relationship (or an extension, or ...).

At low redshifts, the Hubble relationship is linear; at high-z, the relationship can be used to distringuish between different cosmological models.

And yes, you're right, the observational data are what they are; any theory which claims to have applicability to cosmology needs to address these data.

But perhaps you are referring to something else? The time-dilation observed in the high-z 1a SNe light-curves?

BTW first observation of doppler efect was made by Ole Roemer (1644-1710).

If you mean the observations of the times of Jovian satellite phenomena (occultations etc), then that's usually described as an early measurement of the speed of light, not the doppler effect.

If not, would you mind saying what you had in mind?

But perhaps you are referring to something else? The time-dilation observed in the high-z 1a SNe light-curves?

Here is lovely article about it!
G. Goldhaber et al. arXiv:astro-ph/0104382 v1 24 Apr 2001

If you mean the observations of the times of Jovian satellite phenomena (occultations etc), then that's usually described as an early measurement of the speed of light, not the doppler effect.

Is it or not? The Doppler efect. Please, no offence!

Michael Mozina wrote:

Nereid wrote:Unlike the four, previous, key cosmological observations*, this last one - the primordial abundance of light nuclides - involves application of several aspects of modern physics.

All of which are predicated on the *assumption* that stars are not mass separated by atomic weight. If you remove that single assumption, then what?

Actually, it is predicated on no such thing at all ... the observations (and there are a very great many of them) are not - principally - of stars at all, but of matter which has not, as far as we can tell, ever been anywhere near any stars ...

You've mentioned this "stars are (not) mass separated by atomic weight" at least once before, but I doubt that very many folk reading the words have any idea what they mean. Why not start a separate thread on it?

Should you do so, please ensure that any ideas you present that are not part of mainstream astronomy (astrophysics, etc) are backed up by references to papers published in relevant peer-reviewed journals.

nikki wrote:

But perhaps you are referring to something else? The time-dilation observed in the high-z 1a SNe light-curves?

Here is lovely article about it!
G. Goldhaber et al. arXiv:astro-ph/0104382 v1 24 Apr 2001

[snip]

Yes, that's certainly a powerful result, cosmologically speaking.

Michael Mozina wrote:

Nereid wrote:Actually, it is predicated on no such thing at all ...

Sure it is if you're talking about the total picture. It may not be applicable to all observations, but any overall abundance numbers of elements in the universe will be directly effected by whether or not plasma mass separates in a sun.

the observations (and there are a very great many of them) are not - principally - of stars at all, but of matter which has not, as far as we can tell, ever been anywhere near any stars ...

Yes, there are observations where this assumption is less critical.

[snip]

Can you substantiate your assertion?

With references to the relevant, key papers, can you explain how estimates of the primordial abundance of H, D, and 4He*, from astronomical observations, are impacted by these assumptions?

Note that this question is quite limited in its scope - only three nuclides (the three most abundant!), only primordial abundance, and only the astronomical observations which are used to make the relevant estimates.

Specifically, please do NOT introduce matters outside this limited scope.

*To make an estimate of the primordial abundance of both 3He and 7Li, from the relevant astronomical observations, does require assumptions about stellar evolution, which includes standard stellar models.

Michael Mozina wrote:

Nereid wrote:

Michael Mozina wrote:Yes, there are observations where this assumption is less critical.

Can you substantiate your assertion?

Your discussion style is highly unusual and very unorthodox at times Nereid. It's hard to follow.

All I acknowledged was that my mass separation argument does not necessarily apply as well to plasma clouds in space. For whatever reason you then launched into inquisition mode and asked me to demonstrate something about forbidden lines. I'm not making any assertions about forbidden lines, I was simply acknowledging that mass separated sun theories aren't necessarily applicable to every type of spectral analysis of every plasma formation.

Let's refresh our understanding of this thread, and of the relevant posts, shall we?

It is about cosmology - the nature and origin of the universe.

I covered five observational cosmology tests - Olbers' paradox, the Hubble relationship, the large-scale structure of the universe, the CMB, and the primordial abundance of light nuclides - and commented that only this last one is not direct - you need quantum theory to appreciate why it's a cosmological test.

At that point, you objected: "All of which are predicated on the *assumption* that stars are not mass separated by atomic weight. If you remove that single assumption, then what?"

I assumed you were referring to only the last cosmological test (primordial abundance of light nuclides), and pointed out that this test has nothing to do with stars at all - so your assertion seems irrelevant.

Now it seems that your comment has nothing to do with observational cosmology at all (it's about stars, and only stars) - so why introduce it into a thread about cosmology in the first place?

Worse, you now write something about forbidden lines, in this thread ... of course, as anyone can see, I have not mentioned forbidden lines in this thread ... perhaps you misread what I *actually* wrote?

Michael Mozina wrote:

Nereid wrote:Let's refresh our understanding of this thread, and of the relevant posts, shall we?

Ok.

It is about cosmology - the nature and origin of the universe.

I covered five observational cosmology tests - Olbers' paradox,

Yes, and a couple of people have popped that bubble for you now.

They did? Like your quote from HA?

Perhaps we need a refresher on that too!

the Hubble relationship, the large-scale structure of the universe, the CMB, and the primordial abundance of light nuclides - and commented that only this last one is not direct - you need quantum theory to appreciate why it's a cosmological test.

At that point, you objected: "All of which are predicated on the *assumption* that stars are not mass separated by atomic weight. If you remove that single assumption, then what?"

I assumed you were referring to only the last cosmological test (primordial abundance of light nuclides),

Yes, that's exactly what I meant.

and pointed out that this test has nothing to do with stars at all - so your assertion seems irrelevant.

That is incorrect. The *overall* abundance of atoms in the universe is directly affected by whether or not suns are mostly hydrogen, or mostly iron. There are huge implications between these two competing ideas and what that implies about the overall composition of the universe.

Hmm, it seems this thread will go on for quite a bit longer then ...

Let's start with the estimated mass of (IGM, ISM) gas (actually plasma) vs the estimated mass of all the stars, past and present.

For simplicity, let's start with rich clusters: what proportion of the (baryonic) mass in rich clusters is in the form of the IGM (inter-galactic medium), and what in galaxies (gas, dust, and stars)?

(Hint: it's nearly all in the IGM)

The light elements that are often found between stars is not necessarily representative of the whole abundance picture.

Some nebula can be spectroscopically analyzed, but that does not give us a clear picture about the makeup of the universe. I just shows that those areas are typically composed of light elements, which would also be consistent with a mass separated solar theory, where hydrogen and helium and constantly being "shed" into the solar wind, while the heavier elements tend to be held more tightly by gravity.

OK ... so now a) assume all stars are 99% not H, D, He, or Li, b) estimate the mass of all stars compared with the mass of all nebulae.

But, most important for this thread (on observational cosmology), what papers contain calculations on the predicted (primordial) abundances of light nuclides, in a cosmology where suns are mostly iron?

What papers even describe such a cosmology??

Now it seems that your comment has nothing to do with observational cosmology at all (it's about stars, and only stars) - so why introduce it into a thread about cosmology in the first place?

This statement doesn't even make sense to me. Stars are, and always have been a part of observational cosmology. If you are going to claim that an abundance figure is evidence of the validity of current theory, then you will have to demonstrate that your abundance number is accurate in the first place.

[snip]

OK, so what is the direct relevance of stars to observational cosmology, in the sense the *direct* observations of stars can be used as tests of cosmological theories?

Please note the *direct*; indirect observations - such as the fact that no star is older than ~13 bn years - are, of course, quite important.

Hello All

Just passing

Neried said

Hmm, it seems this thread will go on for quite a bit longer then ...

Let's start with the estimated mass of (IGM, ISM) gas (actually plasma) vs the estimated mass of all the stars, past and present.

For simplicity, let's start with rich clusters: what proportion of the (baryonic) mass in rich clusters is in the form of the IGM (inter-galactic medium), and what in galaxies (gas, dust, and stars)?

(Hint: it's nearly all in the IGM)

Neried you are assuming facts from ad hoc ideas.

You are making the assumption that the Big Bang theory is correct and that baryonic mass exists.

As for the oldest star,,,,,,,,,,,,,,that remains to be calculated.

Every time the star goes through a stage or phase of development. Supernova sparks in some cases a compact core that leads to a rejuvination of the star. How many time this happens remains in the hands of the researches. 13 billion years seems to be too short a period.

The reason is that after a supernova the compact core can last over 10 billion years.

harry wrote:Hello All

Just passing

Neried said

Hmm, it seems this thread will go on for quite a bit longer then ...

Let's start with the estimated mass of (IGM, ISM) gas (actually plasma) vs the estimated mass of all the stars, past and present.

For simplicity, let's start with rich clusters: what proportion of the (baryonic) mass in rich clusters is in the form of the IGM (inter-galactic medium), and what in galaxies (gas, dust, and stars)?

(Hint: it's nearly all in the IGM)

Neried you are assuming facts from ad hoc ideas.

You are making the assumption that the Big Bang theory is correct and that baryonic mass exists.

Should I laugh or cry, harry?

I mean, the observational results which lead to conclusions concerning dark matter in rich clusters stand on their own ...

It's true that the estimates of the proportion of mass-energy in the form of DM vs baryonic mass are consistent with those derived from cosmologically relevant observations, but I doubt that even you, harry, would consider this some kind of negative.

More pertinent: baryon: "the baryons are the family of subatomic particles which are made of three quarks. The family notably includes the proton and neutron, which make up the atomic nucleus, [...]"

In other words, what is it that you think your are made of harry, if not baryonic matter?

As for the oldest star,,,,,,,,,,,,,,that remains to be calculated.

Every time the star goes through a stage or phase of development. Supernova sparks in some cases a compact core that leads to a rejuvination of the star. How many time this happens remains in the hands of the researches. 13 billion years seems to be too short a period.

The reason is that after a supernova the compact core can last over 10 billion years.

You've lost me harry, what relevance does this have to the part of my post that you quoted?

Michael Mozina wrote:

Nereid wrote:Please note the *direct*; indirect observations - such as the fact that no star is older than ~13 bn years - are, of course, quite important.

What direct observations are you basing that number on, and what "assumptions" are you making about the composition of stars when you date them?

The best direct evidence is the HR diagrams of globular clusters, compared with the HR diagrams of open clusters.

In textbook astrophysics, these HR diagrams are well accounted for with standard stellar evolution models, which are in turn based on standard models of stars (hydrostatic equilibrium, opacity tables, helioseismology, etc) with inputs from nuclear physics, atomic physics, etc.

Of course, these models are tested six ways to Sunday; among those tests are detailed accounts of intrinsically variable stars, of many kinds.

What might we expect to see from a star that is say 200 billion years old?

In a word, nothing.

Such a star, if it had not evolved off the main sequence, would be an M dwarf (or cooler) ... absolute magnitude ~12; if it had evolved, it would be a very cold neutron star or white dwarf (I don't know, off the top of my head, what the absolute magnitude would be, but likely well below 12).

I guess you might be lucky enough to catch such a star as it entered whatever equivalent of the red giant phase is has (I don't recall the details of this) ...

IOW, you wouldn't be able to see any such star, even with the HST, much beyond a few hundred to thousand parsecs ...