Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
A better term for "dark matter"
203 views
Skip to first unread message
Eric Flesch
Jul 10, 2012, 4:49:15 AM7/10/12
to
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.
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.
cheers, Eric
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.
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.
cheers, Eric
Jos Bergervoet
Jul 10, 2012, 7:05:28 AM7/10/12
to
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
>
> I see CERN is now moving their sights to "finding" dark matter -- just
> another $1.2 billion needed, please.
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,
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,
> 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.
you still are against spending money looking for it?
(Actually we could just as well omit discussion of
the name, then?!)
--
Jos
David Staup
Jul 10, 2012, 10:04:02 AM7/10/12
to
"Eric Flesch" <er...@flesch.org> wrote in message
news:mt2.0-9479...@hydra.herts.ac.uk...
"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?
news:mt2.0-9479...@hydra.herts.ac.uk...
>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:
> 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.
"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?
Eric Flesch
Jul 10, 2012, 4:37:33 PM7/10/12
to
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.
Phillip Helbig---undress to reply
Jul 10, 2012, 4:38:15 PM7/10/12
to
In article <mt2.0-9479...@hydra.herts.ac.uk>, Eric Flesch
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.
<er...@flesch.org> writes:
> 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,
> 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.
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.
Nicolaas Vroom
Jul 11, 2012, 7:44:09 AM7/11/12
to
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
> A new term is badly needed to prevent all this wrong-headedness.
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
http://users.telenet.be/nicvroom/dark_mat.htm
Phillip Helbig---undress to reply
Jul 11, 2012, 8:00:13 AM7/11/12
to
In article <mt2.0-10237...@hydra.herts.ac.uk>, Nicolaas Vroom
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.
<nicolaa...@pandora.be> 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
> 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
> 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
> (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.
Steve Willner
Jul 12, 2012, 2:15:05 AM7/12/12
to
In article <mt2.0-12777...@hydra.herts.ac.uk>,
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
Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de> 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
> 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.
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
Eric Flesch
Jul 12, 2012, 7:57:00 AM7/12/12
to
On Thu, 12 Jul 12 06, Steve Willner <wil...@cfa.harvard.edu> wrote:
>I'm mystified by the OP's suggestion that dark matter isn't matter. ...
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.
>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
>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?
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.
Eric Flesch
Jul 12, 2012, 11:31:59 AM7/12/12
to
On Thu, 12 Jul 12 06, Steve Willner <wil...@cfa.harvard.edu> 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.
Eric Gisse
Jul 13, 2012, 4:49:40 AM7/13/12
to
On Jul 12, 10:31 am, Eric Flesch <e...@flesch.org> wrote:
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.
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.
Eric Flesch
Jul 13, 2012, 10:17:34 AM7/13/12
to
On Fri, 13 Jul 12 08:49:40 GMT, Eric Gisse <jow...@gmail.com> wrote:
>On Jul 12, 10:31 am, Eric Flesch <e...@flesch.org> wrote:
>> Now it occurs to me that "gravitational scalar" and "dark matter" are
>> not all that much different. ...
>On Jul 12, 10:31 am, Eric Flesch <e...@flesch.org> wrote:
>> Now it occurs to me that "gravitational scalar" and "dark matter" are
>
>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
>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.
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.
David Staup
Jul 14, 2012, 3:03:21 AM7/14/12
to
"Eric Flesch" <er...@flesch.org> wrote in message
news:mt2.0-24273...@hydra.herts.ac.uk...
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.
Eric Flesch
Jul 14, 2012, 8:01:29 AM7/14/12
to
On Sat, 14 Jul 12, David Staup <dst...@sbcglobal.net> 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
>Could not gravity be leaking into our 3 dimensions from matter "located" in
>these other dimensions?
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
Nicolaas Vroom
Jul 17, 2012, 4:19:55 PM7/17/12
to
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
> Fluctuations in the cosmic microwave background also distinguish
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
Phillip Helbig---undress to reply
Jul 17, 2012, 5:17:16 PM7/17/12
to
In article <mt2.0-22221...@hydra.herts.ac.uk>, Nicolaas Vroom
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.
<nicolaa...@pandora.be> 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
> On Thursday, July 12, 2012 8:15:05 AM UTC+2, Steve Willner wrote:
>
> > Fluctuations in the cosmic microwave background also distinguish
> > 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
> > 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.
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.
Eric Flesch
Jul 18, 2012, 12:08:28 PM7/18/12
to
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
>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.
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..
Eric Gisse
Jul 19, 2012, 1:56:08 AM7/19/12
to
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
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' ?
[...]
[...]
> 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?
> in a fancy word. Took me 20 years to realize that that emperor
> (thermodynamics) has no clothes either.
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' ?
[...]
Steve Willner
Jul 20, 2012, 2:29:06 AM7/20/12
to
In article <mt2.0-22221...@hydra.herts.ac.uk>,
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.
Nicolaas Vroom <nicolaa...@pandora.be> 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
> 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
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.
Nicolaas Vroom
Jul 24, 2012, 3:20:17 AM7/24/12
to
On Friday, July 20, 2012 8:29:06 AM UTC+2, Steve Willner wrote:
> Yes, that's correct: all cosmological tests "care" only
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
http://users.telenet.be/nicvroom/
> 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
> of course, such as dark energy and neutrinos).
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
http://users.telenet.be/nicvroom/
Jos Bergervoet
Jul 24, 2012, 6:23:31 AM7/24/12
to
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
> 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.
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
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:
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
Phillip Helbig---undress to reply
Jul 25, 2012, 2:26:34 AM7/25/12
to
In article <mt2.0-20193...@hydra.herts.ac.uk>, Nicolaas Vroom
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.
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.
Nicolaas Vroom
Jul 25, 2012, 8:44:27 AM7/25/12
to
Op woensdag 25 juli 2012 08:26:34 UTC+2 schreef Phillip Helbig---undress to reply het volgende:
> In article <mt2.0-20193...@hydra.herts.ac.uk>, Nicolaas Vroom
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
http://users.telenet.be/nicvroom/
> In article <mt2.0-20193...@hydra.herts.ac.uk>, Nicolaas Vroom
> <nicolaa...@pandora.be> writes:
>
> > How difficult terminology is becomes clear when you study Time
> > Magazine of 23July 2012, which reads:
>
>
> > 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
> explain rotation curves) can be baryonic? Are you implying that all
> dark matter in the universe can be baryonic? Obviously simply finding a
> 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
> to imply that it would be almost irrelevant.
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
http://users.telenet.be/nicvroom/
Nicolaas Vroom
Jul 25, 2012, 2:58:47 PM7/25/12
to
At dinsdag 24 juli 2012 12:23:31 UTC+2 schreef Jos Bergervoet het volgende:
> 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
http://users.telenet.be/nicvroom/
> 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
> > 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.
> > 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.
> other scale do you see in their text?!
> What you (probably)
> wanted to say was "Speed of stars inside a galaxy as
> a function of distance to the center of that galaxy."
> But more importantly: introduction of this "function"
> is irrelevant for describing the problem.
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!
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"
Is this the case in the Local group ?
In the Virgo Cluster ?
Does unseen forms of matter are they baryonic or nonbaryonic ?
Nicolaas Vroom
http://users.telenet.be/nicvroom/
Jos Bergervoet
Jul 25, 2012, 4:24:33 PM7/25/12
to
On 7/25/2012 8:58 PM, Nicolaas Vroom wrote:
> At dinsdag 24 juli 2012 12:23:31 UTC+2 schreef Jos Bergervoet het volgende:
...
> At dinsdag 24 juli 2012 12:23:31 UTC+2 schreef Jos Bergervoet het volgende:
>> 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.
>> a function of distance to the center of that galaxy."
>
>
>> 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:
>> 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"
"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 ?
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 ?
galaxies.
> In the Virgo Cluster ?
> Does unseen forms of matter are they baryonic or nonbaryonic ?
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
Nicolaas Vroom
Jul 25, 2012, 4:36:42 PM7/25/12
to
Op woensdag 25 juli 2012 20:58:47 UTC+2 schreef Nicolaas Vroom het volgende:
> 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
> 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 ?
> Those "unseen forms of matter" are they baryonic or nonbaryonic ?
Nicolaas Vroom
Nicolaas Vroom
Aug 7, 2012, 4:01:49 PM8/7/12
to
Retransmission.
[Mod. note: it is possible that some postings from the middle of last
week have been lost -- please re-send if you think you might be in
this position -- mjh]
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
http://users.telenet.be/nicvroom/
[Mod. note: it is possible that some postings from the middle of last
week have been lost -- please re-send if you think you might be in
this position -- mjh]
On Wednesday, July 25, 2012 10:24:33 PM UTC+2, Jos Bergervoet wrote:
> On 7/25/2012 8:58 PM, Nicolaas Vroom 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."
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.
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
http://users.telenet.be/nicvroom/
Phillip Helbig---undress to reply
Aug 14, 2012, 4:50:51 PM8/14/12
to
In article <mt2.0-896-...@hydra.herts.ac.uk>, Nicolaas Vroom
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.
<nicolaa...@pandora.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!
> >>> 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.
> 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.
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.
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 ?
> >> 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 ?
> What makes this question so difficult is to
> prove that this extra matter is mainly nonbaryonic.
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.
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"
know that the dark matter cannot be all baryonic.
Christian Froeschlin
Aug 16, 2012, 12:12:31 AM8/16/12
to
Phillip Helbig---undress to reply wrote:
> 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
> know that the dark matter cannot be all baryonic.
"MACHOs [...] account for only 10% to 20% of the dark matter halo".
Richard D. Saam
Aug 26, 2012, 3:17:25 AM8/26/12
to
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
Nicolaas Vroom
Aug 29, 2012, 10:48:19 AM8/29/12
to
Op zondag 26 augustus 2012 09:17:25 UTC+2 schreef
Richard D. Saam het volgende:
> Yes, current models for "primordial nucleosynthesis
> give a firm upper limit on the amount of baryonic matter."
>
> 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
http://users.telenet.be/nicvroom/
Richard D. Saam het volgende:
> 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
> Plasma and Ordinary Matter
> http://www.bnl.gov/bnlweb/pubaf/pr/PR_display.asp?prID=1446
> compared to homogeneous gas phase (current assumption)
> resulting in baryonic dark matter
> as observed today.
>
> Richard D. Saam
"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
http://users.telenet.be/nicvroom/
Phillip Helbig---undress to reply
Aug 30, 2012, 6:25:21 AM8/30/12
to
In article <mt2.0-24699...@hydra.herts.ac.uk>, Nicolaas Vroom
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? :-)
<nicolaa...@pandora.be> 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
> "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 ?
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.
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%.
> 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%.
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.
But, hey, it's NATURE---what do you expect? :-)
Richard D. Saam
Sep 3, 2012, 2:13:16 PM9/3/12
to
On 8/29/12 9:48 AM, Nicolaas Vroom wrote:
> Op zondag 26 augustus 2012 09:17:25 UTC+2 schreef
> Richard D. Saam het volgende:
>
>> 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)
> Op zondag 26 augustus 2012 09:17:25 UTC+2 schreef
> Richard D. Saam het volgende:
>
>> 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.
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?
Nicolaas Vroom
Sep 3, 2012, 2:14:59 PM9/3/12
to
Op donderdag 30 augustus 2012 12:25:43 UTC+2 Phillip Helbig wrote;
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 hugh 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
http://users.telenet.be/nicvroom/
>
> 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
> They mean nonbaryonic matter. Just saying "85" indicates that
> they must mean nonbaryonic (dark) matter
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 hugh 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.
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.
missing matter is almost by definition non baryonic.
Nicolaas Vroom
http://users.telenet.be/nicvroom/
Nicolaas Vroom
Sep 4, 2012, 12:55:46 PM9/4/12
to
Op maandag 3 september 2012 20:13:38 UTC+2 schreef Richard D. Saam het volgende:
> 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
http://users.telenet.be/nicvroom/
> 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 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
http://users.telenet.be/nicvroom/
Nicolaas Vroom
Sep 5, 2012, 7:41:53 AM9/5/12
to
Op dinsdag 4 september 2012 18:56:08 UTC+2 wrote Nicolaas Vroom
het volgende:
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
http://users.telenet.be/nicvroom/
het volgende:
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]
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
http://users.telenet.be/nicvroom/
Richard D. Saam
Sep 5, 2012, 5:34:08 PM9/5/12
to
On 9/4/12 11:55 AM, Nicolaas Vroom wrote:
> Op maandag 3 september 2012 20:13:38 UTC+2 schreef Richard D. Saam het volgende:
>
>> 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.
> Op maandag 3 september 2012 20:13:38 UTC+2 schreef Richard D. Saam het volgende:
>
>> Baryon Oscillation Spectroscopic Survey (BOSS)
>> http://www.sdss3.org/surveys/boss.php
>> presents the current universe analysis of baryonic component
>
>
> This is again an interesting document.
> This documentation mentions:
>
> This is again an interesting document.
> For a detailed description of BOSS, see Section 3 of
> the Project Description PDF.
> http://www.sdss3.org/collaboration/description.pdf
>
> 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,
> 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.
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
Nicolaas Vroom
Sep 7, 2012, 10:54:53 AM9/7/12
to
Op woensdag 5 september 2012 23:34:29 UTC+2 schreef
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
http://users.pandora.be/nicvroom/
Richard D. Saam het volgende:
> 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
> 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
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
http://users.pandora.be/nicvroom/
Phillip Helbig---undress to reply
Sep 9, 2012, 4:04:39 AM9/9/12
to
In article <mt2.0-3868...@hydra.herts.ac.uk>, Nicolaas Vroom
> 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 hugh 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.
> > 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.
>
> 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.
detect.
> Accordingly to Wikipedia a black hole is non baryonic (which I ? )
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 hugh 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)
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
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.
maximum baryonic contribution allowed by nucleosynthesis.
Nicolaas Vroom
Sep 28, 2012, 9:06:15 PM9/28/12
to
On Sunday, September 9, 2012 10:05:00 AM UTC+2, Phillip Helbig wrote:
> In article <mt2.0-3868...@hydra.herts.ac.uk
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 hugh 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
http://users.pandora.be/nicvroom/
> In article <mt2.0-3868...@hydra.herts.ac.uk
> Nicolaas Vroom <nicolaa...@pandora.be> writes:
> > 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:
> > 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.
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 hugh 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
http://users.pandora.be/nicvroom/
Eric Flesch
Sep 30, 2012, 6:19:38 AM9/30/12
to
On Sat, 29 Sep 12 01:06:15 GMT, Nicolaas Vroom wrote:
>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 hugh amount of
>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?"
>baryonic gas of ionized metals around the Milky Way.
I wouldn't be hasty about accepting the conclusions of papers like
this. Many assumptions go into their technique, basically they are
calculating the "halo mass" from absorption line widths. That's a lot
of mass from each assumption and each micrometer of line width. This
"column density ratio" calculation depends on the state of the matter
and any rotation present -- any unmodelled dispersion will yield false
high answers. These authors have modelled these lines as saturated,
in departure from previous authors, see the bottom of their page 5.
From this assumption (and the others) springs a galaxy's worth of
extra matter -- yeah, right.
There was a paper a few years back, I don't have the citation, a
galaxy spectrum was taken and double lines were found. So they didn't
know what to make of that, so they came up with a model where the
galaxy was being disrupted by a hot expanding bubble of gas, thus a
hollow expanding galaxy. Silly idea, but all the press releases hyped
it up like a major new finding. All from a couple of double lines
that they couldn't figure out, chee.
If you look at the literature of 100 years ago, you'll find that many
if not most of them were poppycock. Today, too. This paper is no
game changer.
Eric
0 new messages