On 7/10/2012 10:49 AM, Eric Flesch wrote::

>	I see CERN is now moving their sights to "finding" dark matter -- just another $1.2 billion needed, please.

I think it's not "now". $1.2G is mentioned for a proposed upgrade in the year 2020. At this moment they actually have decided to continue operating at the current 8TeV for many months to come. And after that they will first bring this to 14TeV, which is still not the 1.2 billion upgrade..

>	And there is research afoot to locating the signature of rotating dark matter. All this because of the pernicious terminology "dark matter" which implies that the gap between our universe model and what is observed, is matter,

Of course, even if it is against their own judgement, it would be impolite of CERN to remain unresponsive when told repeatedly by astronomers that such a large portion of the universe is still undetected! After all, detecting things is their business. Some say they are actually quite good at it..

...

>

A new term is badly needed to prevent all this wrong-headedness. There is a quite nice word which seems to have fallen out of favour, and perhaps could be recycled to this more noble purpose: QUINTESSENCE. The word says "we don't know what it is", drips with 5th-dimensional flavour, and could make the CERN-o-nauts put their accelerators back into their pockets. The idea of looking for rotating quintessence, er, dark matter, does sound interesting however, and I look forward to developments. But no $1 billion budget for that, please.

So even if people use the names that you approve of, you still are against spending money looking for it? (Actually we could just as well omit discussion of the name, then?!)

-- Jos

"Eric Flesch" wrote:

>

I see CERN is now moving their sights to "finding" dark matter -- just another $1.2 billion needed, please. And there is research afoot to locating the signature of rotating dark matter. All this because of the pernicious terminology "dark matter" which implies that the gap between our universe model and what is observed, is matter, when it instead could be and is indeed likely to be stuff of another sort, if not only the absence of stuff between our ears. I'm amazed how easily all are led by a mere word.. A new term is badly needed to prevent all this wrong-headedness.

Again from Lavoisier:

"The impossibility of separating the nomenclature of a science from the science itself, is owing to this, that every branch of physical science must consist of three things; the series of facts which are the objects of the science, the ideas which represent these facts, and the words by which these ideas are expressed."

One MUST have the FACTS before one chooses the words to express (clearly) the ideas.

Are we there yet?

On Tue, 10 Jul 12, Jos Bergervoet wrote:

>	On 7/10/2012 10:49 AM, Eric Flesch wrote:

>>	The idea of looking for rotating quintessence, er, dark matter, does sound interesting however, and I look forward to developments. But no $1 billion budget for that, please.

>	So even if people use the names that you approve of, you still are against spending money looking for it?

No, the project to detect rotating (i.e. revolving) dark matter is mainstream astronomy, not CERN, so normal budgets apply and that is OK. It's actually a good test of the nature of "dark matter", for if the rotation is demonstrated to exist, that's evidence that dark matter is indeed matter-like. The problem is that if / when no such rotation is found, it will not be taken as evidence that dark matter is *not* matter-like. Oh, for a different word.

In article , Eric Flesch wrote:

>

A new term is badly needed to prevent all this wrong-headedness. There is a quite nice word which seems to have fallen out of favour, and perhaps could be recycled to this more noble purpose: QUINTESSENCE. The word says "we don't know what it is", drips with 5th-dimensional flavour, and could make the CERN-o-nauts put their accelerators back into their pockets.

I think "dark matter" is a fair-enough term. It was introduced because, errm, dark matter would explain the observations. Why should we expect all matter to be bright? Dark matter seems a very natural hypothesis. Yes, there is MOND etc but if we just call it, say, fjweofjweo, then there is no indication of what its properties should be. Dark matter tells us what they are (even if it turns out to be something which has the same effect).

I don't like quintessence in this context, but it has already been taken to denote "dark energy" (another term I don't like) with an equation of state different from that of the cosmological constant.

On Tuesday, July 10, 2012 10:49:15 AM UTC+2, Eric Flesch wrote:

>	A new term is badly needed to prevent all this wrong-headedness.

The new term should describe the issue or physical phenomena as much as possible What is at stake is the missing mass problem, of which there are two flavours:
(1) one related to "each" Galaxy and (2) one related to the whole Universe.
The first is simply stated as the amount of mass (1) which is the difference between the amount of mass (2) calculated to support the observed (flat) galaxy rotation curve (grv) and the observed amount of visible matter (3). The fact that the calculated grv based on mass #3 and the observed grv are different is a reflection of mass #1.
The problem is what is missing mass. Mass #3 is visible baryonic matter. The most obvious candidate for this missing mass #1 is invisible baryonic matter i.e. cold matter, small rocks, dust and gass clouds (Only when all this cold baryonic matter is taken into account and there is a mismatch nonbaryonic matter can be considered)
The second is physical of a complete different order of the first. The mass density of a Galaxy and the mass density of the Universe are two completely different quantities. On the other the question is the same: How much warm and cold baryonic matter is there in the Universe. That means the most appropiate name should be: cold baryonic matter.

Nicolaas Vroom
https://www.nicvroom.be/dark_mat.htm

In article , Nicolaas Vroom writes:

>	On Tuesday, July 10, 2012 10:49:15 AM UTC+2, Eric Flesch wrote:

> >	A new term is badly needed to prevent all this wrong-headedness.

>

The new term should describe the issue or physical phenomena as much as possible What is at stake is the missing mass problem, of which there are two flavours: (1) one related to "each" Galaxy and (2) one related to the whole Universe. The first is simply stated as the amount of mass (1) which is the difference between the amount of mass (2) calculated to support the observed (flat) galaxy rotation curve (grv) and the observed amount of visible matter (3). The fact that the calculated grv based on mass #3 and the observed grv are different is a reflection of mass #1. The problem is what is missing mass. Mass #3 is visible baryonic matter. The most obvious candidate for this missing mass #1 is invisible baryonic matter i.e. cold matter, small rocks, dust and gass clouds

> (Only when all this cold baryonic matter is taken into account and there is a mismatch nonbaryonic matter can be considered) > The second is physical of a complete different order of the first. The mass density of a Galaxy and the mass density of the Universe are two completely different quantities. On the other the question is the same: How much warm and cold baryonic matter i > That means the most appropiate name should be: cold baryonic matter.

There are not just two scales, namely galaxy and universe, but also intermediate scales. For example, the dynamics of galaxy clusters indicate dark matter on scales much more than galaxy scales (and much more than the sum of the masses of the galaxies---including the galactic dark matter---in the cluster). In general, the larger the scale one observes, the more dark matter is necessary, but it does level off at the scale of superclusters, say, at about the level required to give a total density of the universe of Omega=0.27 or so, in line with many other lines of evidence.

We know from constraints from primordial nucleosynthesis a pretty good upper bound on the amount of dark matter. Thus, at least some dark matter is non-baryonic, probably most of it.

In article , Phillip Helbig---undress to reply writes:

>	We know from constraints from primordial nucleosynthesis a pretty good upper bound on the amount of dark matter. Thus, at least some dark matter is non-baryonic, probably most of it.

Fluctuations in the cosmic microwave background also distinguish between baryonic and non-baryonic dark matter. There's a cute calculator tool at http://lambda.gsfc.nasa.gov/toolbox/education/cmb_plotter/

I'm mystified by the OP's suggestion that dark matter isn't matter. For the baryons, there can't be any doubt. The non-baryonic dark matter (at least so far as we know now) interacts gravitationally with both itself and with baryons in the same way as any other matter does. Its density varies with cosmic scale factor in the same way as other matter (again so far as we know now) and not in the same way as radiation. So why shouldn't we call it matter?

I agree that "dark energy" is not an ideal term. What it means, as far as I can tell, is "some additional cosmological effect, for example but not necessarily a cosmological constant." Obviously we need a shorthand for that, and I'm afraid "dark energy" is what became popular. As Phillip mentioned, quintessence is already in use for a particular form of dark energy.

"Black hole" is another term that's universally used but is probably less than ideal. I'm sure there are plenty more such terms. Good luck getting everyone (or anyone!) to change. Professionals and people with a serious interest in the subject know what is behind the words, and for the rest, the ideas are obscure no matter what words are used.

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

On Thu, 12 Jul 12 06, Steve Willner wrote:

>	I'm mystified by the OP's suggestion that dark matter isn't matter. ...

>

The non-baryonic dark matter (at least so far as we know now) interacts gravitationally with both itself and with baryons in the same way as any other matter does. Its density varies with cosmic scale factor in the same way as other matter (again so far as we know now) and not in the same way as radiation. So why shouldn't we call it matter?

Your doubly-stated phrase "so far as we know now" is the succint answer. Not enough evidence -- our observations are too beholden to our limited instrumentation. All we have to deduce dark matter is gravity, but gravity is not well understood, having never been united into the concordance model. So we know there's extra gravity, but to infer extra matter from that should stop when we find ourselves chasing phantoms -- after all, it could be something else after all.

On Thu, 12 Jul 12 06, Steve Willner wrote:

>	I'm mystified by the OP's suggestion that dark matter isn't matter.

On reflection, I've often mentioned a "gravitational scalar" which seems to pervade the ISM, which gravitationally detaches stars from eachother and so enables them to mingle ambiently within elliptical galaxies and globular clusters. Also present in the IGM, allowing HI to ooze away from galaxies like NGC 3628.

Now it occurs to me that "gravitational scalar" and "dark matter" are not all that much different. Suppose "dark matter" subtends a gravitational aura in places where it phantom-like inhabits. Much like my gravitational scalar. You could see evidence for this in close large bodies which are less bound to eachother than you might expect from their masses. Hmm.

On Jul 12, 10:31 am, Eric Flesch wrote:

>

On Thu, 12 Jul 12 06, Steve Willner wrote: I'm mystified by the OP's suggestion that dark matter isn't matter. On reflection, I've often mentioned a "gravitational scalar" which seems to pervade the ISM, which gravitationally detaches stars from eachother and so enables them to mingle ambiently within elliptical galaxies and globular clusters. Also present in the IGM, allowing HI to ooze away from galaxies like NGC 3628. Now it occurs to me that "gravitational scalar" and "dark matter" are not all that much different. Suppose "dark matter" subtends a gravitational aura in places where it phantom-like inhabits. Much like my gravitational scalar. You could see evidence for this in close large bodies which are less bound to eachother than you might expect from their masses. Hmm.

Congratulations, you have re-invented TeVeS.

Saying that dark matter is 'actually' some (tensor|{,pseudo}vector| scalar) field doesn't really add anything to the discussion because all you have done is pushed back the genesis of the problem back another level.

On Fri, 13 Jul 12 08:49:40 GMT, Eric Gisse wrote:

>	On Jul 12, 10:31 am, Eric Flesch wrote:

>>	Now it occurs to me that "gravitational scalar" and "dark matter" are not all that much different. ...

>	Saying that dark matter is 'actually' some (tensor|{,pseudo}vector| scalar) field doesn't really add anything to the discussion because all you have done is pushed back the genesis of the problem back another level.

It does add something because it shows e.g. that galaxies can't have very extended haloes because "dark matter" raises the gravitational background noise level. So the IGM is dark matter dominated, gravitationally.

Mind you, I think "gravitational scalar" is a far better term than "dark matter", but maybe "dark matter" isn't as bad a placeholder as I was thinking.

"Eric Flesch" wrote: in message

news:mt2.0-24273-1342094220@hydra.herts.ac.uk...

>	On Thu, 12 Jul 12 06, Steve Willner wrote:

>>

I'm mystified by the OP's suggestion that dark matter isn't matter. ... The non-baryonic dark matter (at least so far as we know now) interacts gravitationally with both itself and with baryons in the same way as any other matter does. Its density varies with cosmic scale factor in the same way as other matter (again so far as we know now) and not in the same way as radiation. So why shouldn't we call it matter?

>

Your doubly-stated phrase "so far as we know now" is the succint answer. Not enough evidence -- our observations are too beholden to our limited instrumentation. All we have to deduce dark matter is gravity, but gravity is not well understood, having never been united into the concordance model. So we know there's extra gravity, but to infer extra matter from that should stop when we find ourselves chasing phantoms -- after all, it could be something else after all.

Could the "matter" (source of extra gravity) be "somewhere" else?

Gravity is "possibly" weak because some leaks into "other" dimensions.

Could not gravity be leaking into our 3 dimensions from matter "located" in these other dimensions?

I realize this question might be better answered by the physicists working on M-theory but this strikes me a relevant here-now.

On Sat, 14 Jul 12, David Staup wrote:

>	Could not gravity be leaking into our 3 dimensions from matter "located" in these other dimensions?

I've certainly speculated thusly, but then we're back to the idea that gravity comes only from matter. If it were as simple as that, then gravity should have been successfully incorporated into the TOE.

Consider dimensions, they are space or time which seem like very different things but are shown to be united as space-time. So could not other dimensions be (apparently) very different again? I am guessing that gravity may be a dimension, which is why it won't fit into the TOE.

Anyway, all speculation in response to your "could ...". cheers

On Thursday, July 12, 2012 8:15:05 AM UTC+2, Steve Willner wrote:

>	Fluctuations in the cosmic microwave background also distinguish between baryonic and non-baryonic dark matter. There's a cute calculator tool at http://lambda.gsfc.nasa.gov/toolbox/education/cmb_plotter/

I can understand that there is a relation between baryonic and non-baryonic matter with the CMB power spectrum but not with dark matter because dark matter is a concept related to human constraints i.e. the human eye and that has nothing to do with the physical processes which happened "around" the Big Bang.

When you goto: http://background.uchicago.edu/~whu/intermediate/summary.html in the section "Damping Tail" the following parameters are introduced:
baryon density, matter density and dark baryons.
With baryon density they should mean all baryons in a region of space (visible and invisible). With matter density they should mean the total of all baryon and nonbaryon (or not use). The concept of dark baryons is IMO related to the CMB not relevant.

Nicolaas Vroom

writes:

>	On Thursday, July 12, 2012 8:15:05 AM UTC+2, Steve Willner wrote:

> >	Fluctuations in the cosmic microwave background also distinguish between baryonic and non-baryonic dark matter. There's a cute calculator tool at http://lambda.gsfc.nasa.gov/toolbox/education/cmb_plotter/

>

I can understand that there is a relation between baryonic and non-baryonic matter with the CMB power spectrum but not with dark matter because dark matter is a concept related to human constraints i.e. the human eye and that has nothing to do with the physical processes which happened "around" the Big Bang. When you goto: http://background.uchicago.edu/~whu/intermediate/summary.html in the section "Damping Tail" the following parameters are introduced: baryon density, matter density and dark baryons. With baryon density they should mean all baryons in a region of space (visible and invisible). With matter density they should mean the total of all baryon and nonbaryon (or not use). The concept of dark baryons is IMO related to the CMB not relevant.

This is true as far as it goes. However, we know from non-CMB sources what the amounts of total matter, total baryonic matter and non-dark matter are, so we can figure out how much dark matter there must be.

On Tue, 17 Jul 12, Phillip Helbig---undress to reply wrote:

>	we know from non-CMB sources what the amounts of total matter, total baryonic matter and non-dark matter are, so we can figure out how much dark matter there must be.

Reminscent of thermodynamics, where "entropy" is calculated as the residue of the temperature & enthalpy, etc. -- but the entropy is actually only the gap between calculation and measurement, dressed up in a fancy word. Took me 20 years to realize that that emperor (thermodynamics) has no clothes either.

This is further remiscent of the excluded middle in mathematics, which is used by the rationalists to "prove" useless things like Cantorian infinities, and which constructivists avoid -- they say you need to construct something for it to be real, and not use gaps. Yes, I'm a constructivist, it's a very sane worldview..

On Wednesday, July 18, 2012 11:08:28 AM UTC-5, Eric Flesch wrote:

[...]

>	Reminscent of thermodynamics, where "entropy" is calculated as the residue of the temperature & enthalpy, etc. -- but the entropy is

>	actually only the gap between calculation and measurement, dressed up in a fancy word. Took me 20 years to realize that that emperor (thermodynamics) has no clothes either.

Huh?

Entropy is simply a calculation of the number of states a system can have.

How does that translate to 'residue of temperature' and such? To say nothing of being the 'gap between calculation and measurement' ?

[...]

In article , Nicolaas Vroom writes:

>	I can understand that there is a relation between baryonic and non-baryonic matter with the CMB power spectrum but not with dark matter because dark matter is a concept related to human constraints

Yes, that's correct: all cosmological tests "care" only about baryonic and non-baryonic matter (and other constituents, of course, such as dark energy and neutrinos).

The historical situation has been that very little of the baryonic matter was directly detected, and of course none of the non-baryonic matter has been. The term "baryonic dark matter" therefore meant all the baryonic matter not associated with stars and stellar remnants. Matter that is associated with stars and known forms of stellar remnants is called "luminous matter," even though not all of it is actually detectable. With these definitions, "baryonic dark matter" is almost but not quite synonymous with "baryonic matter," and sometimes people will use one when they mean the other.

Recent evidence suggests that much of the baryonic matter is in the form of very hot (>10^6 K) gas associated with galaxy clusters. To the extent this matter is detected by X-ray emission, it is no longer "dark," but it may take some time for the terminology to catch up.

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

On Friday, July 20, 2012 8:29:06 AM UTC+2, Steve Willner wrote:

>	Yes, that's correct: all cosmological tests "care" only about baryonic and non-baryonic matter (and other constituents, of course, such as dark energy and neutrinos).

How difficult terminology is becomes clear when you study Time Magazine of 23July 2012, which reads: "Take dark matter. Galaxies are large enough and spin fast enough that by rights they ought to fly apart. The fact that they don't means the gravity from some unseen form of matter is holding them together. And in order to exert so much pull, it would have to be an awful lot of that matter--fully 80% of the universe. Most physicists believe that the invisible stuff is made of a particle of some kind. If that particle has mass, it's interacting with the Higgs. Find the Higgs responsible and you may pull back the curtain on what the dark particles are."

IMO this text is misleading because different orders of scale are compared. IMO a more appropiate text with the word "dark matter" is: Take the missing matter problem. The measured speed of a galaxy as a function of distance is called the galaxy rotation curve (grv) In order to calculate this curve (using Newton's Law) you can follow two roads: (1) by starting from a distribution of matter in bulge and disk from what is observed (2) by starting from a theoretical distribution of matter. The object of this second calculation is that calculated grv resembles what is observed. The two amounts of matter do not match. The difference between the two is called the missing matter problem. The issue is what is this missing matter. The most obvious solution is baryonic matter in objects of all sizes. Including blackholes, stars, brown stars, planets, asteroids and gasses. Only when all the baryonic matter is included nonbaryonic matter can be considered. At the scale of the Universe a similar problem exists. The amount of nonbaryonic matter involded at that scale can be different. If the LHC finds any new nonbaryonic particle it does not mean that missing matter problem is solved.

Nicolaas Vroom https://www.nicvroom.be/

On 7/24/2012 9:20 AM, Nicolaas Vroom wrote:

>	On Friday, July 20, 2012 8:29:06 AM UTC+2, Steve Willner wrote:

>>	Yes, that's correct: all cosmological tests "care" only about baryonic and non-baryonic matter (and other constituents, of course, such as dark energy and neutrinos).

>

How difficult terminology is becomes clear when you study Time Magazine of 23July 2012, which reads: "Take dark matter. Galaxies are large enough and spin fast enough that by rights they ought to fly apart. The fact that they don't means the gravity from some unseen form of matter is holding them together. And in order to exert so much pull, it would have to be an awful lot of that matter--fully 80% of the universe. Most physicists believe that the invisible stuff is made of a particle of some kind. If that particle has mass, it's interacting with the Higgs. Find the Higgs responsible and you may pull back the curtain on what the dark particles are." IMO this text is misleading because different orders of scale are compared.

No, they only talk about the galactic scale. What other scale do you see in their text?!

>	IMO a more appropiate text with the word "dark matter" is: Take the missing matter problem. The measured speed of a galaxy as a function of distance is called the galaxy rotation curve (grv) In

Wrong! "Speed of a galaxy as a function of distance" is the famous Hubble relation. What you (probably) wanted to say was "Speed of stars inside a galaxy as a function of distance to the center of that galaxy." That would make it a fairly complicated sentence.. (for Time Magazine, I mean! Not for us, of course.) But more importantly: introduction of this "function" is irrelevant for describing the problem.

>	order to calculate this curve (using Newton's Law) you can follow two roads:

Unnecessary complication by talking about a "curve"! Again: you don't need a curve, or a function. Almost any individual star orbit in the galaxy demonstrates the problem. Time Magazine is therefore correct in just using the simpler statement that the spinning of the galaxy indicates extra force. It would be wrong to suggest that it is more subtle than that!

For completeness, they could have added: "All over the universe we see similar cases where the movement of large structures indicates extra force from the gravity of unseen forms of matter." But good writing requires restriction!

--
Jos

In article , Nicolaas Vroom writes:

>

How difficult terminology is becomes clear when you study Time Magazine of 23 July 2012, which reads: "Take dark matter. Galaxies are large enough and spin fast enough that by rights they ought to fly apart. The fact that they don't means the gravity from some unseen form of matter is holding them together. And in order to exert so much pull, it would have to be an awful lot of that matter--fully 80% of the universe. Most physicists believe that the invisible stuff is made of a particle of some kind. If that particle has mass, it's interacting with the Higgs. Find the Higgs responsible and you may pull back the curtain on what the dark particles are." IMO this text is misleading because different orders of scale are compared. IMO a more appropiate text with the word "dark matter" is: Take the missing matter problem. The measured speed of a galaxy as a function of distance is called the galaxy rotation curve (grv) In order to calculate this curve (using Newton's Law) you can follow two roads: (1) by starting from a distribution of matter in bulge and disk from what is observed (2) by starting from a theoretical distribution of matter. The object of this second calculation is that calculated grv resembles what is observed. The two amounts of matter do not match. The difference between the two is called the missing matter problem. The issue is what is this missing matter. The most obvious solution is baryonic matter in objects of all sizes. Including blackholes, stars, brown stars, planets, asteroids and gasses. Only when all the baryonic matter is included nonbaryonic matter can be considered. At the scale of the Universe a similar problem exists. The amount of nonbaryonic matter involded at that scale can be different. If the LHC finds any new nonbaryonic particle it does not mean that missing matter problem is solved.

Yes, the text is misleading, especially the part about tying the Higgs to dark matter. Yes, there is some connection, but in the sense that there are connections between most things. The article implies that the search for the Higgs was primarily to understand dark matter, which is not the case. However, I have a few questions to your text:

Are you implying that all galactic dark matter (i.e. that needed to explain rotation curves) can be baryonic? Are you implying that all dark matter in the universe can be baryonic? Obviously simply finding a non-baryonic particle with mass won't solve the dark-matter problems you describe (othewise massive neutrinos would have done so), but you seem to imply that it would be almost irrelevant.

Op woensdag 25 juli 2012 08:26:34 UTC+2 Phillip Helbig writes:

>	In article <mt2.0-20193-1343114417@hydra.herts.ac.uk>, Nicolaas Vroom writes:

> >	How difficult terminology is becomes clear when you study Time Magazine of 23July 2012, which reads:

>

Are you implying that all galactic dark matter (i.e. that needed to explain rotation curves) can be baryonic? Are you implying that all dark matter in the universe can be baryonic? Obviously simply finding a non-baryonic particle with mass won't solve the dark-matter problems you describe (othewise massive neutrinos would have done so), but you seem to imply that it would be almost irrelevant.

Yes I'am implying that "all" the extra matter needed to explain rotation curves could be baryonic. The issue is here the relation between baryonic matter that releases photons (hot and luminous) versus that does not. Only when all that baryonic matter is included nonbaryonic can be considered.

For the Universe as a whole ofcourse nonbaryonic matter is relevent. The issue is here the relation between baryonic versus nonbaryonic. The answer on this question depents very much about the amount of baryonic matter in all the galaxies. This relation can be different for each.

The amount of baryonic matter in the solar system is 99% (guess). Maybe someone can give a more detailed answer.

Nicolaas Vroom
https://www.nicvroom.be/

At dinsdag 24 juli 2012 12:23:31 UTC+2 Jos Bergervoet wrote:

>	On 7/24/2012 9:20 AM, Nicolaas Vroom wrote:

> >	How difficult terminology is becomes clear when you study Time Magazine of 23July 2012, which reads: "Take dark matter And in order to exert so much pull, it would have to be an awful lot of that matter--fully 80% of the universe.

>	No, they only talk about the galactic scale. What other scale do you see in their text?!

In the above text they try to explain dark matter in a galaxy and with dark matter in the universe. That is difficult, specific in relation with nonbaryonic matter.

>	What you (probably) wanted to say was "Speed of stars inside a galaxy as a function of distance to the center of that galaxy."

That is ofcourse what I wanted to say.

>	But more importantly: introduction of this "function" is irrelevant for describing the problem.

You can not describe the missing matter problem by using the concept: "ought to fly apart"

>	Time Magazine is therefore correct in just using the simpler statement that the spinning of the galaxy indicates extra force. It would be wrong to suggest that it is more subtle than that!

They use the sentence "and spin fast enough". What does that mean ?

>	For completeness, they could have added: "All over the universe we see similar cases where the movement of large structures indicates extra force from the gravity of unseen forms of matter"

What large structures do you have in mind ? Is this the case in the Local group ? In the Virgo Cluster ? Does unseen forms of matter are they baryonic or nonbaryonic ?

Nicolaas Vroom https://www.nicvroom.be/

On 7/25/2012 8:58 PM, Nicolaas Vroom wrote:

>	At dinsdag 24 juli 2012 12:23:31 UTC+2 Jos Bergervoet wrote:

...

>>	wanted to say was "Speed of stars inside a galaxy as a function of distance to the center of that galaxy."

>	That is of course what I wanted to say.

>>	But more importantly: introduction of this "function" is irrelevant for describing the problem.

>	You can not describe the missing matter problem by using the concept: "ought to fly apart"

Maybe one could use slightly more words: "Either they should be spinning much slower or there must be extra force from unseen matter," for instance. Time Magazine directly jumps to the second conclusion since we know how fast they spin to begin with! Why do you think that does not describe it clearly?

>>	Time Magazine is therefore correct in just using the simpler statement that the spinning of the galaxy indicates extra force. It would be wrong to suggest that it is more subtle than that!

>	They use the sentence "and spin fast enough". What does that mean ?

I think most readers would understand that what is meant is: "Fast enough to fly apart if the only binding force would be gravity from the matter we can see."

>>	For completeness, they could have added: "All over the universe we see similar cases where the movement of large structures indicates extra force from the gravity of unseen forms of matter"

>	What large structures do you have in mind ? Is this the case in the Local group ?

Indeed groups of galaxies (or pairs of galaxies.

>	In the Virgo Cluster ? Does unseen forms of matter are they baryonic or nonbaryonic ?

Many readers from a broad public (with some scientific knowledge) would probably think automatically of black holes as a first option! An article like this should go on to tell that the central black hole in most galaxies turns out not to solve it and that a population of black holes distributed throughout the galaxy is also ruled out (some posters in this newsgroup might disagree!)

Only after that, the claim that new particles are needed will make sense. I think your quoted paragraph could be re-written in that way without even using more words. But still I don't think it's too bad the way it is..

BTW (since you ask about it,) Suppose it would be black holes, would you call that baryonic or nonbaryonic?!

--
Jos

Op woensdag 25 juli 2012 20:58:47 UTC+2 Nicolaas Vroom wrote:

>	What large structures do you have in mind ? Is this the case in the Local group ? In the Virgo Cluster ? Does unseen forms of matter are they baryonic or nonbaryonic ?

This last line should be:

>	Those "unseen forms of matter" are they baryonic or nonbaryonic ?

Nicolaas Vroom

On Wednesday, July 25, 2012 10:24:33 PM UTC+2, Jos Bergervoet wrote:

>	On 7/25/2012 8:58 PM, Nicolaas Vroom wrote:

>>	At dinsdag 24 juli 2012 12:23:31 UTC+2 wrote: Jos Bergervoet:

>>>	Time Magazine is therefore correct in just using the simpler statement that the spinning of the galaxy indicates extra force. It would be wrong to suggest that it is more subtle than that!

>>	They use the sentence "and spin fast enough". What does that mean ?

>	I think most readers would understand that what is meant is: "Fast enough to fly apart if the only binding force would be gravity from the matter we can see."

I stay to my objection that this reasoning is too simple. The only way to explain the missing matter problem is first of all by refering to the galaxy rotation curve and Newton's Law. To modify NL or to claim that almost all the missing matter is nonbaryonic is tricky. IMO, if you consider the full life cycle (flc) of a star than the amount of baryonic matter is constant. From a visible point of view that is not the case. A star's flc starts and ends invisible in dust.

>>>	For completeness, they could have added: "All over the universe we see similar cases where the movement of large structures indicates extra force from the gravity of unseen forms of matter"

>>	What large structures do you have in mind ? Is this the case in the Local group ?

>	Indeed groups of galaxies (or pairs of galaxies.

How do you know that based on the movement of galaxies in a cluster there is extra matter involved in the space inbetween the galaxies ? IMO that is a very difficult question to answer. What makes this question so difficult is to prove that this extra matter is mainly nonbaryonic. What makes this question also difficult is that first of all you must estimate the total masses of all the galaxies involved, many of which can be small and or are barely visible. To use the viral theory is also tricky.

In the book UNIVERSE in chapter "Galaxies" in paragraph "Most of the matter in the universe has yet to be discovered" we read (at end): The more mundane suggestions include dim stars and "Jupiter-like planets". IMO that sentence should be modified like: "The most obvious solution includes: planet sized objects, asteroids, dust and gas clouds"

Nicolaas Vroom https://www.nicvroom.be/

writes:

> >>>

Time Magazine is therefore correct in just using the simpler statement that the spinning of the galaxy indicates extra force. It would be wrong to suggest that it is more subtle than that!

>	I stay to my objection that this reasoning is too simple. The only way to explain the missing matter problem is first of all by refering to the galaxy rotation curve and Newton's Law. To modify NL or to claim that almost all the missing matter is nonbaryonic is tricky.

Using Newton's law, the motion of the stars does not match their mass. So there is unseen matter or Newton's law is wrong.

>	IMO, if you consider the full life cycle (flc) of a star than the amount of baryonic matter is constant. From a visible point of view that is not the case. A star's flc starts and ends invisible in dust.

Yes, but even if invisible baryonic matter is added, the mass and the motion still do not match.

> >>>

For completeness, they could have added: "All over the universe we see similar cases where the movement of large structures indicates extra force from the gravity of unseen forms of matter"

> >>	What large structures do you have in mind ?

Probably clusters of galaxies.

> >>	Is this the case in the Local group ?

Yes.

> >	Indeed groups of galaxies (or pairs of galaxies.

Yes.

>	How do you know that based on the movement of galaxies in a cluster there is extra matter involved in the space inbetween the galaxies ?

Because if they weren't, the galaxies would no longer be in the cluster.

>	What makes this question so difficult is to prove that this extra matter is mainly nonbaryonic.

There is a completely independent line of argument, based on primordial nucleosynthesis, which gives a firm upper limit on the amount of baryonic matter. If there is evidence for other matter, it must be non-baryonic.

>	What makes this question also difficult is that first of all you must estimate the total masses of all the galaxies involved, many of which can be small and or are barely visible. To use the viral theory is also tricky.

Gravitational lensing can also be used to measure the mass of the cluster, and depends neither on seeing the mass or some tracer of it nor on assuming the cluster is virialized.

>

In the book UNIVERSE in chapter "Galaxies" in paragraph "Most of the matter in the universe has yet to be discovered" we read (at end): The more mundane suggestions include dim stars and "Jupiter-like planets". IMO that sentence should be modified like: "The most obvious solution includes: planet sized objects, asteroids, dust and gas clouds"

This is a rather old book, right? These have been ruled out since we know that the dark matter cannot be all baryonic.

Phillip Helbig---undress to reply writes:

>	In article , Nicolaas Vroom writes:

>>	In the book UNIVERSE in chapter "Galaxies" in paragraph "Most of the matter in the universe has yet to be discovered" we read (at end): The more mundane suggestions include dim stars and "Jupiter-like planets".

>

>	This is a rather old book, right? These have been ruled out since we know that the dark matter cannot be all baryonic.

The ninth edition of this book (from 2011) indeed states

"MACHOs [...] account for only 10% to 20% of the dark matter halo".

On 8/14/12 3:50 PM, Phillip Helbig---undress to reply wrote:

>	In article , Nicolaas Vroom writes:

>>	What makes this question so difficult is to prove that this extra matter is mainly nonbaryonic.

>	There is a completely independent line of argument, based on primordial nucleosynthesis, which gives a firm upper limit on the amount of baryonic matter. If there is evidence for other matter, it must be non-baryonic.

>>	What makes this question also difficult is that first of all you must estimate the total masses of all the galaxies involved, many of which can be small and or are barely visible. To use the viral theory is also tricky.

>	Gravitational lensing can also be used to measure the mass of the cluster, and depends neither on seeing the mass or some tracer of it nor on assuming the cluster is virialized.

>>

In the book UNIVERSE in chapter "Galaxies" in paragraph "Most of the matter in the universe has yet to be discovered" we read (at end): The more mundane suggestions include dim stars and "Jupiter-like planets". IMO that sentence should be modified like: "The most obvious solution includes: planet sized objects, asteroids, dust and gas clouds"

>	This is a rather old book, right? These have been ruled out since we know that the dark matter cannot be all baryonic.

Yes, current models for "primordial nucleosynthesis give a firm upper limit on the amount of baryonic matter." but consider recent ~200 GeV physical experiments at Brookhaven National Lab (BNL) replicating primordial reaction conditions.

Ref: Closing in on the Border Between Primordial Plasma and Ordinary Matter http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=1446

"the different phases exist under different conditions of temperature and density, which can be mapped out on a ?phase diagram,? where the regions are separated by a phase boundary akin to those that separate liquid water from ice and from steam. But in the case of nuclear matter, scientists still are not sure where to draw those boundary lines. RHIC is providing the first clues."

Current primordial nucleosynthesis models may be simplistic in defining single phase reaction models (as BNL would indicate). Anyone with a chemistry background can appreciate the interplay between different phases and the resultant multi phase products from reactants. Some of these baryonic phase products may proceed through the Universe expansion at first light (z~3000) and not be observed by as WMAP Baryonic Acoustic Oscillation because of their differing density phase compared to homogeneous gas phase (current assumption) resulting in baryonic dark matter as observed today.

Richard D. Saam

Op zondag 26 augustus 2012 09:17:25 UTC+2 Richard D. Saam wrote:

>	Yes, current models for "primordial nucleosynthesis give a firm upper limit on the amount of baryonic matter." Ref: Closing in on the Border Between Primordial Plasma and Ordinary Matter http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=1446

This is an excellent document

>	compared to homogeneous gas phase (current assumption) resulting in baryonic dark matter as observed today. Richard D. Saam

In Nature Vol 488 page 432 we read: "Dark Matter hugs the Sun Dark matter constitutes roughly 85 of all matter in the Universe and there may be more of it near the Sun than previously assumed." The issue is what do they mean with dark matter: nonbaryonic matter, baryonic matter or both ? And if both what is the relation between both. In fact the question is what was this relation nb versus b around the time of the Big Bang and what is the relation at present for the Universe. With baryonic matter I mean the elements of the periodic table. It is easy possible that this relation is not constant and started with nb 100% versus b 0%.

Next we read: "The presence of dark matter can be inferred from its gravitational effect on the rotation of the Milky Way" Again here you have the same issue; what is the relation The answer here could be: nb 5% versus b 95%.

Next we read: "on the motion of about 2000 stars local to the Sun Their model suggests that the density of dark matter near the Sun is higher than had been thought." Again the same issue. I expect what they mean here is baryonic matter. That means the amount of baryonic matter in the disc is higher than original thought. Implying less need for nonbaryonic matter to solve the rotation issue.

http://dx.doi.org/10.1111/j.1365-2966.2012.21608.x

In the article they mention K dwarfs. My understanding is that means baryonic matter.

Nicolaas Vroom https://www.nicvroom.be/

In article , Nicolaas Vroom writes:

>	"Dark Matter hugs the Sun Dark matter constitutes roughly 85 of all matter in the Universe and there may be more of it near the Sun than previously assumed." The issue is what do they mean with dark matter: nonbaryonic matter, baryonic matter or both ?

They mean nonbaryonic matter. Just saying "85" indicates that they must mean nonbaryonic (dark) matter, not dark (possibly baryonic) matter. Yes, I agree that many people use the terms sloppily.

>	And if both what is the relation between both. In fact the question is what was this relation nb versus b around the time of the Big Bang and what is the relation at present for the Universe.

The same. The number of baryons in the universe is fixed (unless they decay, but even then not an appreciable number can have decayed since primordial nucleosynthesis).

>	With baryonic matter I mean the elements of the periodic table. It is easy possible that this relation is not constant and started with nb 100% versus b 0%.

No. This would be a huge departure from accepted understanding.

>	Next we read: "The presence of dark matter can be inferred from its gravitational effect on the rotation of the Milky Way" Again here you have the same issue; what is the relation The answer here could be: nb 5% versus b 95%.

Gravitational detection of dark matter can't distinguish between baryonic and non-baryonic.

>

Next we read: "on the motion of about 2000 stars local to the Sun Their model suggests that the density of dark matter near the Sun is higher than had been thought." Again the same issue. I expect what they mean here is baryonic matter. That means the amount of baryonic matter in the disc is higher than original thought. Implying less need for nonbaryonic matter to solve the rotation issue. http://dx.doi.org/10.1111/j.1365-2966.2012.21608.x In the article they mention K dwarfs. My understanding is that means baryonic matter.

K dwarfs are definitely baryonic. But this doesn't jibe with "85".

But, hey, it's NATURE---what do you expect? :-)

On 8/29/12 9:48 AM, Nicolaas Vroom wrote:

>	Op zondag 26 augustus 2012 09:17:25 UTC+2 Richard D. Saam writes:

>>	Yes, current models for "primordial nucleosynthesis give a firm upper limit on the amount of baryonic matter." Ref: Closing in on the Border Between Primordial Plasma and Ordinary Matter http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=1446

>	This is an excellent document

>>	compared to homogeneous gas phase (current assumption) resulting in baryonic dark matter as observed today.

Baryon Oscillation Spectroscopic Survey (BOSS) http://www.sdss3.org/surveys/boss.php presents the current universe analysis of baryonic component mirroring the z~3000 event.

The contained quote is noted: "(in the panels) We have removed the smooth component to more clearly show the oscillations, which are the BAO signal of interest."

This data removal implies another universe phase component other then the BAO. Could this phase be baryonic of different primordial nucleosynthetic phase density origin?

How much was removed?

Op donderdag 30 augustus 2012 12:25:43 UTC+2 Phillip Helbig wrote:

>	They mean nonbaryonic matter. Just saying "85" indicates that they must mean nonbaryonic (dark) matter

The question is at what distance from our galaxy can you describe that the enclosed sphere contains 85% nb matter versus 15% b matter? IMO this should be true at roughly 1.5 million ly from our galaxy.

With baryonic matter I mean matter consisting mainly of 3 quarks. All other combinations are non baryonic (nb) (i.e. messons)

If you consider our solor system the amount of nb matter is almost zero. If you consider the space included to our nearest star the same. In 1 ly the same, maybe close to 1. If you consider the central bulge also very small.
Accordingly to Wikipedia a black hole is non baryonic (which I ? ) but even if that is case the amount of nb matter stays small. Also in the disc the amount of nb matter is small. All the nb matter in our Galaxy is in the sphere (NFW law) of roughly 50000 ly which is maybe 10-20% of all the matter in our Galaxy. (not 85)

However this creates a serious problem because how can it be possible that the Andromeda galaxy (distance 2.3 million ly) that it moves in Our direction when our galaxy is shielded by this huge amount of nb matter. In principle this is only possible when the amount of nb matter at 1.5 million ly is zero (or close)

> >	It is easy possible that this relation is not constant and started with nb 100% versus b 0%.

>	No. This would be a huge departure from accepted understanding.

Why is it not possible that direct after the Big Bang there was no baryonic matter (3 quarks), but only something simpler which slowly evolved into baryonic matter and slowly evolved in all the elements of the periodic table ?

>

> >	Next we read: "The presence of dark matter can be inferred from its gravitational effect on the rotation of the Milky Way" Again here you have the same issue; what is the relation The answer here could be: nb 5% versus b 95%.

>	Gravitational detection of dark matter can't distinguish between baryonic and non-baryonic.

That is correct, making it difficult to accept that all the missing matter is almost by definition non baryonic.

Nicolaas Vroom
https://www.nicvroom.be/

Op maandag 3 september 2012 20:13:38 UTC+2 Richard D. Saam wrote:

>	Baryon Oscillation Spectroscopic Survey (BOSS) http://www.sdss3.org/surveys/boss.php presents the current universe analysis of baryonic component mirroring the z~3000 event.

This is again an interesting document. This documention mentions: For a detailed description of BOSS, see Section 3 of the Project Description PDF. http://www.sdss3.org/collaboration/description.pdf

Perform a search in that document with "dark matter" At page 27 you will find a match in the paragraph: "The dark matter Halo." When you study that paragraph I get the impression that with dark matter they mean stars i.e. they mean baryonic matter.

[Mod. note: under no circumstances does anyone mean 'stars' when they refer to dark matter. In the specific part you refer to, they are talking about using the motions of stars to trace the gravitational potential of the dark matter -- i.e. exactly the method by which the presence of dark matter in the Galaxy was first inferred -- mjh]

The whole chapter "Seque-2 Science" is about stars. Nowhere they mention non baryonic matter.

The only place where they mention non baryonic matter is at the top of page 3 (?): "a baryon-to-dark-matter ratio of approx. 1:6" No clear description is shown what they mean with this nor how this relation is calculated.

Nicolaas Vroom https://www.nicvroom.be/

Op dinsdag 4 september 2012 18:56:08 UTC+2 Nicolaas Vroom wrote:

See: http://www.sdss3.org/collaboration/description.pdf

>

[Mod. note: under no circumstances does anyone mean 'stars' when they refer to dark matter. In the specific part you refer to, they are talking about using the motions of stars to trace the gravitational potential of the dark matter -- i.e. exactly the method by which the presence of dark matter in the Galaxy was first inferred -- mjh]

When you read the whole article there are 5 issues involved: 1) a baryon-to-dark-matter ratio of approx. 1:6 (page 3) 2) the nature of space and time (page 8) 3) the "baryon acoustic oscillation" method, pioneered in the SDSS, is especially attractive for its simplicity and its freedom from systematic uncertainties. (page 3) 4) dark matter halo (page 6,7,18 and 27) 5) H(z)

First a definition: With baryonic matter I mean all matter which main constituent is the 3 quark concept. With non baryonic matter all other forms (quark combinations)

Related to issue #4 the following sentence (p22) is interesting: "The chemical abundance information from the SEGUE-2 data, in combination with the kinematics, will be an important constraint on how the physical processes governing star formation in low-mass dark matter halos are etc " Two questions. 1) What is the definition of dark matter halo ? 2) How do you know low-mass ? I expect that the answer on Q2 is because there is almost no missing matter involved (using Galaxy rotation curve). And because the Grc is involved this missing matter should be in the disc, the halo or both. Studying the above sentence at least some of the matter in the halo is baryonic (including faint satelite galaxies) The question in this case is how much matter in the halo is actual baryonic versus non baryonic. And what is this relation for the whole galaxy. And how does this relation compare with issue #1.

Issue #2 is interesting because they do not mention space-time.

Issue #3 is related to paragraph 3.1 BAO. The question is what is the physical relation with non baryonic matter in this picture i.e with the sound waves frozen into the plasma.

Issue #5: In paragraph 3.1 is mentioned that using BAO you can measure H(z). Unfortunate the document does not give any results.

Nicolaas Vroom https://www.nicvroom.be/

On 9/4/12 11:55 AM, Nicolaas Vroom wrote:

>	Op maandag 3 september 2012 20:13:38 UTC+2 Richard D. Saam wrote:

>>	Baryon Oscillation Spectroscopic Survey (BOSS) http://www.sdss3.org/surveys/boss.php presents the current universe analysis of baryonic component mirroring the z~1000 event.

>

This is again an interesting document. This documentation mentions: For a detailed description of BOSS, see Section 3 of the Project Description PDF. http://www.sdss3.org/collaboration/description.pdf The only place where they mention non baryonic matter is at the top of page 3 (?): "a baryon-to-dark-matter ratio of approx. 1:6" No clear description is shown what they mean with this nor how this relation is calculated.

Continuing this 'dark matter' discussion, Pavel Naselsky, the Niels Bohr Institute gives himself another few months to solve the dark matter mystery by analyzing Planck galactic haze data.

http://www.nbi.ku.dk/english/news/news12/the-mystery-of-dark-matter-may-be-near-to-being-deciphered/

http://arxiv.org/abs/1208.5483

Pavel suggests 20 - 40 GHz galactic haze is a direct indicator of the unknown 'dark matter' because there are no galactic structural mechanisms to produce such radiation in a known physical manner.

Richard D. Saam

Op woensdag 5 september 2012 23:34:29 UTC+2 Richard D. Saam wrote:

>

Continuing this 'dark matter' discussion, Pavel Naselsky, the Niels Bohr Institute gives himself another few months to solve the dark matter mystery by analyzing Planck galactic haze data. http://www.nbi.ku.dk/english/news/news12/the-mystery-of-dark-matter-may-be-near-to-being-deciphered/ http://arxiv.org/abs/1208.5483

The picture that emerges (partly based on the information previously mentioned that 85% of all matter in the Universe is non baryonic) that in principle all non baryonic matter could be heavy particles. However this # 85% is not constant. It starts with almost 0% in our neighbourhood. Slowly increasing in the halo of our galaxy to roughly 20% (?) to a distance of the outer edge of the disc. and then increasing slowly to the 85% at a distance of 1 million ly (?) and than staying constant to the outer edge of the Universe. This picture indicates low non baryonic matter bubbles around galaxies.

However this picture makes it difficult to understand how galaxies can be attracted towards each other.

Nicolaas Vroom https://www.nicvroom.be/

In article , Nicolaas Vroom wrote:

> >	They mean nonbaryonic matter. Just saying "85" indicates that they must mean nonbaryonic (dark) matter

>	The question is at what distance from our galaxy can you describe that the enclosed sphere contains 85% nb matter versus 15% b matter? IMO this should be true at roughly 1.5 million ly from our galaxy.

Sounds about right.

>	With baryonic matter I mean matter consisting mainly of 3 quarks. All other combinations are non baryonic (nb) (i.e. messons)

Right, but they are not stable, hence not a dark-matter candidate.

>	If you consider our solor system the amount of nb matter is almost zero.

We don't know. Depending on what it is, it might be difficult to detect.

>	Accordingly to Wikipedia a black hole is non baryonic (which I ? )

It depends on how it is formed, i.e. from the collapse of a star or as a primordial black hole (before nucleosynthesis).

>

However this creates a serious problem because how can it be possible that the Andromeda galaxy (distance 2.3 million ly) that it moves in Our direction when our galaxy is shielded by this huge amount of nb matter. In principle this is only possible when the amount of nb matter at 1.5 million ly is zero (or close)

Non-baryonic matter interacts only gravitationally, so there is no shielding possible.

>	Why is it not possible that direct after the Big Bang there was no baryonic matter (3 quarks), but only something simpler which slowly evolved into baryonic matter and slowly evolved in all the elements of the periodic table ?

It's not impossible, as far as I know, but would involve new physics, thus making the cure worse than the disease, so to speak.

>	That is correct, making it difficult to accept that all the missing matter is almost by definition non baryonic.

This comes from estimating the total gravitationally and subtracting the maximum baryonic contribution allowed by nucleosynthesis.

On Sunday, September 9, 2012 10:05:00 AM UTC+2, Phillip Helbig wrote:

>	In article

>	Nicolaas Vroom wrote:

> >	That is correct, making it difficult to accept that all the missing matter is almost by definition non baryonic.

>	This comes from estimating the total gravitationally and subtracting the maximum baryonic contribution allowed by nucleosynthesis.

The following document gives maybe some answers: http://arxiv.org/abs/1205.5037 "A huge reservoir of ionized gas around the Milky Way: Accounting for the Missing Mass?"

When I understand the article correct there is a huge amount of baryonic gas of ionized metals around the Milky Way.

The question arises if this amount is enough to explain the flat Galaxy Rotation curve.

And the next question if the answer is NO: How much mass is still missing to explain the flat curve.

Nicolaas Vroom https://www.nicvroom.be/

Back to my home page Contents of This Document