Fermi and dark matter

[Michael Mozina]

I want to be sure here:
You are asserting that for each galaxy in a galactic cluster there are ~40 galaxies comprised of asteroids.

No. I'm trying to get you to *finally* admit that the technique you are using is physically incapable of distinguishing between "lumps of normal stuff" (like coal) and "collisionless, non baryonic matter". I'm also *amazed* that you claimed that it could not be related to MACHO forms of matter when in fact some studies suggest that a significant portion (20%) of the "missing mass" could be found in MACHO forms of DM.

I'm also amazed that you believe that we have the ability to rule out things like "lumps of coal" when in fact we don't have the technology to do that. Someone sold you a bill of goods about the abilities and limits of our technologies.

What happened to the stars that these asteroids formed around?

They blew up, or burned out?

Any and every theory that you might come up with that "explains" how "non baryonic matter" came to be found in that location can also be applied to any type of normal matter. The "collisionless" issue is overcome by simple "lumps" of normal material rather than simply *assuming* like you do that the whole thing is composed of nothing but ions.

If you can accept that non current carrying particles come streaming into this area to heat the region, then it's also possible that whole "lumps of particles" do exactly the same thing for exactly the same reasons. If gravity attracts the inbound particles, or the particle flow is due to gravitational slingshot effects between galaxies, then the "inbound lumps" are due to gravitational attraction, or the lump flow is due to lumps being slung back and forth between galaxies. There's really no logical explanation for "non baryonic matter' that would not also apply to "lumpy material". Lumpy material slams into the Earth every single night. In a Occum's razor argument your "non baryonic matter" becomes unnecessary because it can be explained by "small lumpy matter' and the state of our current technology precludes you from distinguishing between the two. More importantly "small lumpy matter" shows up on Earth in shooting stars, whereas "non baryonic matter" hasn't ever managed to once trip a single LIGO experiment.

 

[Michael Mozina]

Look at the neutrino cross section. Calculate how many times an average neutrino will collide with something in 13.7 billion years of orbiting the galaxy. If the number is much less than 1 we call it collisionless. If the number is close to 1 we call it nearly collisionless. Heck, even globular clusters of stars are nearly collisionless.

Sure, but then by that definition, all things "lumpy" are also "collisionless" and lumpy stuff shows up in the atmosphere of Earth. Occum won't be kind to you either.

MACHOs would also be collisionless. Black holes would be collisionless. That is why they were considered dark matter candidates---because dark matter is located in places/configurations that can only occur for something collisionless.

So essentially all I'm doing is throwing "rocks and asteroids" and "dusty dense clumps of plasma" into the mix. I simply see far too many more 'empirically attractive" things to choose from if all I'm trying to do is explain those blue blobs that "passed through" the collision process.

The "discussion of how these particles came to be located where they are" is called "galaxy formation" and has been one of the major topics of astrophysics for most of a century.

Sure but only in the past maybe 20 years or so (since Hubble really) have we even been able to really 'see" with any real "resolution". Even still our ability to pick out individual 'lumps' at a distance is extremely limited. I simply see no evidence for a need for an exotic form of matter.

Funny, MACHOs and massive neutrinos ARE collisionless hypothetical objects that there is no experimental evidence for. (Actually, they are collisionless hypothetical objects that there is abundant evidence AGAINST.)

I didn't say anything about "massive neutrinos" by the way. The key difference is that MACHO proposals of "dark matter" do *NOT* require a "new form" of matter. Neutrinos are thought to have mass and they physically interact with normal matter. You don't have the technology necessary to rule out "small lumps" of material, and even small lumps of material would suffice to explain those blue blobs that RC seems so interested in. New forms of matter are completely unnecessary to explain why some types of matter "pass through" and why some do not.

 

[ben m]

So essentially all I'm doing is throwing "rocks and asteroids" and "dusty dense clumps of plasma" into the mix.

Dust is not invisible; it is an IR emitter and a broadband absorber. This is well-known and we have a very good idea of the Milky Way's dust budget. Plasma is not collisionless, not even close---indeed, it's about as collisional as you could possibly ask for.

I would be willing to listen to an argument that rocks in a certain size range could have escaped detection, both in emission and absorbtion spectra. Are you qualified to make such an argument? I'm skeptical. I would also be willing to listen to an argument that rocks in this size range are indeed collisionless---both from the constraint of having nearly-collisionless orbit dynamics and also in remaining rocks rather than getting pulverized into dust.

ETA: without those questions answered, rocks CANNOT be the dark matter, and there's no point even thinking about the bizarre cosmology it would require---a universe consisting of 18% hydrogen, 2% helium, and 80% carbon/oxygen/iron, where almost all of the metals end up in weird rocks and the stars somehow wind up as nearly-pure H/He? Given that you think the Sun is a ball of iron, I know this doesn't convince you of anything, but I want to point out that DM-hypothesis-building is not even as simple as "invent something collisionless".

I didn't say anything about "massive neutrinos" by the way. The key difference is that MACHO proposals of "dark matter" do *NOT* require a "new form" of matter. Neutrinos are thought to have mass and they physically interact with normal matter.

You are misinformed. The three known neutrinos all have masses below 2.2 electron volts, far too light to have the gravitational dynamics we see for dark matter. If you want to hypothesize a yet-undiscovered fourth neutrino with M > 1000 eV, you are welcome to do so; this would be (in most ways) a perfectly supportable dark matter hypothesis.

 

[Michael Mozina]

Dust is not invisible; it is an IR emitter and a broadband absorber. This is well-known and we have a very good idea of the Milky Way's dust budget. Plasma is not collisionless, not even close---indeed, it's about as collisional as you could possibly ask for.

Whereas you and RC might percieve these plasmas to be uniformly distributed and 99% ionized protons and electrons, they may instead by 'clumpy dust" and not all that evenly distributed. The overall "budget" isn't really in question, just the "layout and distribution". A heavier, more dense 'clump' of say iron, nickel, silicon and calcium, might easily 'pass through' and hardly be influenced by a few run ins with a few protons and electrons from the other plasma stream.

I would be willing to listen to an argument that rocks in a certain size range could have escaped detection, both in emission and absorbtion spectra. Are you qualified to make such an argument? I'm skeptical.

I was actually thinking more in term of 'rocks' rather than clumps of dust by the way, but the basic concept would apply to anything significantly more "massive' or dense (or both) than single protons. I doubt I'm 'qualified' to make that argument mathematically to your satisfaction which I assume is what you're after.

I would also be willing to listen to an argument that rocks in this size range are indeed collisionless---both from the constraint of having nearly-collisionless orbit dynamics and also in remaining rocks rather than getting pulverized into dust.

Well, obviously they would not be completely collisionless anymore than neutrinos are completely collisionless. I would expect that some of them would indeed get pulverized and end up in the pink areas.

ETA: without those questions answered, rocks CANNOT be the dark matter,

And likewise that missing mass cannot be "collisionless matter" because no such thing exists in nature. You can't overlook your own "unanswered questions" only because you've provided a mathematical presentation.

and there's no point even thinking about the bizarre cosmology it would require---a universe consisting of 18% hydrogen, 2% helium, and 80% carbon/oxygen/iron, where almost all of the metals end up in weird rocks and the stars somehow wind up as nearly-pure H/He? Given that you think the Sun is a ball of iron, I know this doesn't convince you of anything, but I want to point out that DM-hypothesis-building is not even as simple as "invent something collisionless".

As you might imagine, it's just not quite that simple for me personally. FYI I do not believe that the sun is a "ball of iron" but rather I believe that it is a composition of various heavy and lighter elements (like our own planet) with a mostly hydrogen and helium upper atmosphere. I'm therefore not the least "put off" by the idea that this layout of matter would have a radical impact on the composition of stars. In fact that is a "highly appealing" and attractive aspect of the proposition to me personally and completely congruent with the solar images on my website.

You are misinformed. The three known neutrinos all have masses below 2.2 electron volts, far too light to have the gravitational dynamics we see for dark matter.

I'm not suggesting that neutrinos could make up all the missing mass, just some (small) amount of it.

If you want to hypothesize a yet-undiscovered fourth neutrino with M > 1000 eV, you are welcome to do so; this would be (in most ways) a perfectly supportable dark matter hypothesis.

Which is exactly why I would not ever do that.

 

[edd]

I personally do not believe that all matter and energy was ever collected to a single "lump".

I'd not describe the Big Bang like that either.

I also happen to believe that various elements mass separate in suns and I believe that hydrogen and helium are most abundant because they most easily escape the gravity wells of suns. I therefore don't really care about "your" nucleosynthesis problem.

Can't help you there, but BBN is successful at predicting elemental abundances and it's a hard theory to compete with.

 

[Michael Mozina]

While we are on the topic, I do find it amusing when some people suggest that astrophysicists don't study plasmas when they are the bread and butter of much of their work

Ya, well, when they use terms and energy exchange mechanisms that Alfven referred to a "pseudoscience", and they can't explain simple things that Birkeland empirically explained 100 years ago, it's very hard to believe that they have a real good grasp of plasma physics. I've yet to meet a single astronomer that has actually read "Cosmic Plasma" by Alfven.

We point Rhessi and Fermi at the Earth as we see gamma rays from electrical discharges in the Earth's atmosphere. We point the same equipment at the sun, we observe the same high energy wavelengths from high temperature plasma in the solar atmosphere and astronomers chalk it up to "magnetic reconnection"?

 

[Michael Mozina]

I'd not describe the Big Bang like that either.

Well, let's put it this way. I do not believe that all matter that exists in the universe today was created in a singular event 13.7 billion years ago.

Can't help you there, but BBN is successful at predicting elemental abundances and it's a hard theory to compete with.

Keep in mind that all of that "success" you're talking about is predicated upon whether or not a sun is actually made of mostly hydrogen and helium ions. In 4 or 5 years of these online debates, I've yet to hear anyone explain that first gold running difference image or Kosovichev's Doppler image on my website using a hydrogen/helium solar theory.

 

[Tubbythin]

What I do not fullly understand is why you believe that *any* gamma rays come from "dark matter". Have you ever seen it demonstrated?

Anything and everything "could" be a "cause", but only certain physical processes are *known* to release gamma rays. Now I can't honestly say the binary stars release more gamma rays, but since all stars emit them, it's certain that binary stars *do* emit them too, perhaps in larger quantities. It's certainly not a 'huge leap of faith' to believe that stars emit gamma rays or even that binary pairs in the core emit more of them. I can see own own sun in the Fermi images.

Physics isn't about whether something is a leap of faith ro not. Its about whether the quantitative theory matches the quantitative observations.

My point is that there could be any number of legitimate theories to explain gamma rays that do not involve any new type of matter, nor rely upon any unproven assertions. Past papers that have attributed these gamma rays from 'dark matter' in the core essentially had the rug pulled out from under them in this paper. There's no need for an exotic material and therefore any theory that relies upon exotic material is already at a disadvantage in terms of "simplicity", not to mention "empirical physics".

If this were the only evidence for dark matter then you might have a point. But it isn't.

I'm quite certain that MACHO forms of "dark matter" exist in nature. I am equally sure that cometary and meteorite material exists in nature too. I can see their effect on nature every night when I look at the stars. I'm pretty sure that neutrinos have mass and that mass makes up some of the "missing mass" in the universe too. I do not however have any evidence that exotic forms of matter exist or have any effect on me or nature. I therefore "lack belief" in SUSY particles with ad hoc properties.

SUSY particles do not have ad hoc properties. I've explained this several times already.

IMO any theory that requires exotic particles is making an "extraordinary" claim and as such it requires extraordinary support.

Good job its got then isn't it. Multiple, independent experiments all point in exactly the same direction.

Missing mass does not necessarily equate to "exotic mass", and giving hypothetical particles hypothetical 'properties' is just silly IMO.

Why? Before they were experimentally observed the neutrino and the top quark were hypothetical particles with hypothetical properties.

Such a theory will necessarily have to be "last on the list" in terms of serious consideration, and *any* theory that doesn't require hypothetical new forms of matter is automatically going to be more 'scientifically credible" in terms of empirical physics.

Scientific credibility is basically just a measure of how the quantitative predictions of the theory match the quantitative observations. In that respect there are only two possibilities. New particles or a new law of gravity. SO if its last on the list, its last on a list of two. I think most astronomers would say its actually top.

 

[ben m]

And likewise that missing mass cannot be "collisionless matter" because no such thing exists in nature. You can't overlook your own "unanswered questions" only because you've provided a mathematical presentation.

Your position seems to be "Nature cannot contain anything that we haven't
been able to see yet." In 1955, would you have said the same thing about neutrinos. In 1993 you would have said the same thing about the top quark.

Dark matter is currently HYPOTHESIZED to be a new particle with certain properties, in exactly the same way that numerous new particles have been hypothesized in the past for various reasons. When experiments were performed, some of those particles (charm, bottom, top, W, Z, neutrino, positron, gluons) were in fact discovered, and their hypotheses thus proven correct. Others (pentaquark, techniquarks, magnetic monopoles, mixed sterile neutrinos, diquarks, right-handed W) were more or less proven false. Others (Higgs, SUSY, axion, Z', KK, 4th generation, etc.) are still outstanding and may be proven/disproven in future experiments. Other particles, of course, were discovered before anyone formulated a hypothesis: electrons, protons, photons, neutrons, muons, pions, strange quarks.

I'm not suggesting that neutrinos could make up all the missing mass, just some (small) amount of it.

It's some of the mass of the Universe, sure, but it's not bound to the large mass concentrations (galaxies and clusters) where we see dark matter.

 

[ben m]

And likewise that missing mass cannot be "collisionless matter" because no such thing exists in nature. You can't overlook your own "unanswered questions" only because you've provided a mathematical presentation.

Don't make me repeat myself: collisionless matter, for the purposes of the dark matter observation, is already seen in nature. Neutrinos, stars, MACHOs, are all familiar collisionless systems from the point of view of galaxy formation/dynamics. You just argued that rocks and dust are collisionless. Are you confused about this?

The difference between rocks, MACHOs, stars, etc., and "dark matter" is that rocks, MACHOs, stars are visible in telescopes. The difference between neutrinos and dark matter is that neutrinos are fast-moving due to their low mass.

Stop repeating that "we don't know of anything collisionless". We do. Stop repeating that we don't know of anything that doesn't interact with light. We do.

 

[Reality Check]

No. I'm trying to get you to *finally* admit that the technique you are using is physically incapable of distinguishing between "lumps of normal stuff" (like coal) and "collisionless, non baryonic matter".
..snipped usual rant....

I am not using any technique. Astronomers are.
The way of physically distinguishing between "lumpy stuff" and collisionless, non baryonic matter is simple: "lumpy stuff" forms in galaxies and remains there. The ICM is between galaxies. Thus there is no "lumpy stuff" in the ICM.

To be more exact the space between galaxies may contain tiny amounts of "lumpy stuff". I guess that every few million years a supernova could eject matter at the escape valocity of a galaxy and that this matter might clump up to form some "lumpy stuff".

The X-ray observations of the Bullet Cluster, MACS J0025.4-1222 and Abell 520 show that their ICM has a small proportion of matter that acts as a plasma should. It collides, slows down, forms shock waves, heats up and emits more X-rays.

The gravitational lensing data from the Bullet Cluster, MACS J0025.4-1222 and Abell 520 show that their ICM has a large proportion of matter that acts differently from normal matter. This cannot be "lumpy stuff" because there is not enough "lumpy stuff" observed between galaxies to account for the gravitational lensing data.

Your assertion is that dark matter is "lumpy stuff" and so the ICM must be made of a large proportion of "lumpy stuff". You present no evidence of this.



Astronomers seem to think that that the ICM is not "lumpy stuff". I think that the reasons for this are:

• "Lumpy stuff" like stars, planets, moons, asteroids, etc. form in galaxies. They stay there except in the case of exceptional events.
• "Lumpy stuff" is not dark.
  • "Lumpy stuff" emits light.
  • "Lumpy stuff" absorbs light.
  • Astronomers are really good at detecting things that emit or absorb light.

ETA
ben m's comment about "a universe consisting of 18% hydrogen, 2% helium, and 80% carbon/oxygen/iron, where almost all of the metals end up in weird rocks and the stars somehow wind up as nearly-pure H/He" can be expressed for the galactic clusters.

Your assertion leads to a belief that the mass in galactic clusters consists of:

• 2% in galaxies (mostly H & He).
• 14% in the ICM (mostly H & He).
• 84% in rocks in the ICM (mostly C, O and Fe).

You may (or may not) know that C, O and Fe are created in stars by fusion, i.e. H and He are converted to C, O and Fe. This means that sometime in the past the number of stars were much more than there were in these galactic clusters. So if astronomers look further away, i.e. further back into time, galaxies will (according to you) become more numerous or bigger to contain the ~40 times increase in the number of stars.

The observation that galaxies do not do this falsifies your idea.

 

[sol invictus]

Geez, why are you complaining about dark matter? If you don't agree with any of the conclusions of mainstream astrophysics, then of course you have no reason to believe in dark matter, dark energy, gravitational lensing, the Hubble relation, accretion disks, synchrotron radiation, extrasolar planets, blue straggler stars.

If you're so much of a contrarian that you can't accept stellar interior hydrostatics, which depend on such straightforward physics and math that Jonathan Homer Lane got much of it right in 1870---well, of course you can't accept dark matter. Particle dark matter is an attractive hypothesis because of its agreement with dozens of major aspects of concordance cosmology, none of which you believe or understand.

that^

 

[Michael Mozina]

I am not using any technique. Astronomers are.
The way of physically distinguishing between "lumpy stuff" and collisionless, non baryonic matter is simple: "lumpy stuff" forms in galaxies and remains there. The ICM is between galaxies. Thus there is no "lumpy stuff" in the ICM.

http://www.iop.org/EJ/article/1538-...quest-id=e2cc148d-17f0-473d-a1e6-1fff02dda000

OMG RC. There are whole *STARS* sitting in the ICM dude.

 

[Michael Mozina]

Your position seems to be "Nature cannot contain anything that we haven't
been able to see yet." In 1955, would you have said the same thing about neutrinos.

No, that is a strawman Ben. What I've said is that unlike neutrinos, no laws of physics were being violated by an absence of SUSY particles, and knowledge of the existence of neutrinos came *directly* from "controlled experimentation", not "point at the sky and add math" exercises.

In 1993 you would have said the same thing about the top quark.

No because by then all the other quarks has been seen as had most of the rest of the particles proposed by the standard particle physics model. There was more than ample evidence even by then that the one remaining quark to be found in standard theory would eventually be seen.

Dark matter is currently HYPOTHESIZED to be a new particle with certain properties, in exactly the same way that numerous new particles have been hypothesized in the past for various reasons....

Whereas standard particle physics theory enjoys a ton of empirical support from controlled empirical experimentation, not a single SUSY particle has ever been confirmed to exist in nature. No laws of physics are hanging in the balance in the absence of such particles in nature. No controlled experiment suggests or even hints at their existence.

Keep in mind Ben that it is not the notion of 'missing mass' that I'm questioning. We all seem to accept the idea that "something" is "out there" which our technology and our theories do not account for. The only thing we disagree on is the composition of that material.

I have no evidence that any exotic forms of matter exist in nature whereas I have ample evidence that our technology is still very limited and is incapable of providing us with a clear enough view to even pick out individual stars in a distant galaxy. I have recent evidence that suggests that astronomers have continuously been underestimating the effect of dust on the amount of light we receive from distant galaxies. I also have recent evidence that there are more "small" stars for every massive star that is out there. It seems much more likely that we simply suffer the consequences of a limited technological capability and a "questionable" set of theories related to how much normal matter sits inside any specific galaxy.

 

[Michael Mozina]

Your assertion is that dark matter is "lumpy stuff" and so the ICM must be made of a large proportion of "lumpy stuff". You present no evidence of this.

That is a really ironic comment IMO. Whereas 'lumpy stuff" routinely slams itself into the Earth's atmosphere, and it even occasionally hits the planet surface and other planets in our solar system, your "hypothetical matter" hypothesis is a complete no show in the lab and on Earth.

Those shooting stars we see in the night sky provide ample evidence that the universe contains lots of lumpy stuff. Lumpy stuff is everywhere around us. Shoemaker-Levy 9 was an excellent example of "lumpy stuff" having a profound and direct impact (literally) on a planet. We would not even be able to detect something like a Shoemaker-Levy 9 sized "lump" in the ICM.

Astronomers seem to think that that the ICM is not "lumpy stuff".

Which astronomers? I just cited a paper for you yesterday that shows that up to 20% of that missing matter could easily be found in "MACHO" forms of matter according to "astronomers". Most astronomers I have ever talked with believe that at least some of the missing mass is found inside 'lumpy stuff'. Now I'll grant you that they (as a group) may not believe that "lumpy stuff" is the single largest form of "dark matter", but I've yet to meet any astronomer that believed MACHO theory was total BS.

The term "MACHO" is typically reserved for larger objects by the way, 'larger' than say an asteroid or a moon sized objects. I think everyone I've ever talked to besides you recognizes that at least some of the "missing mass" we're looking for could and probably is found in the form of ordinary lumps of matter that we simply cannot see with our limited technology. In fact I've never met anyone besides you that has tried to claim that clumpy normal matter is not present in the ICM or that 99% of the material in the ICM is ionized. There are complete stars and solar systems in the ICM. There could even be "black holes' out there too.

The techniques that we have used (micro-lensing) which can detect larger forms of MACHO material do tend to demonstrate that at least some of the missing mass is found in large "clumps". That technique however is physically incapable of seeing anything below a certain size because smaller objects will tend to not have any appreciable/measurable affect on the micro-lensing measurements.

 

[Reality Check]

http://www.iop.org/EJ/article/1538-...quest-id=e2cc148d-17f0-473d-a1e6-1fff02dda000

OMG RC. There are whole *STARS* sitting in the ICM dude.

OMG MM. There are whole *STARS* sitting between galaxies dude and astronomers are not dumb enoough to confuse them with the ICM.

There ae not 40 times more stars between galaxies than there are in the galaxies.

 

[Reality Check]

Those shooting stars we see in the night sky provide ample evidence that the universe contains lots of lumpy stuff. Lumpy stuff is everywhere around us. Shoemaker-Levy 9 was an excellent example of "lumpy stuff" having a profound and direct impact (literally) on a planet. We would not even be able to detect something like a Shoemaker-Levy 9 sized "lump" in the ICM.

The existence of shooting strs in the earth's atmosphere is not evidence for "lumpy stuff" in the ICM.
A solar system is not an intracluster medium. Can you see the difference?

Which astronomers? I just cited a paper for you yesterday that shows that up to 20% of that missing matter could easily be found in "MACHO" forms of matter according to "astronomers".
...snip...

Which astronomers? I just cited a paper for you yesterday that shows that up to 8% of that missing matter in the Milky Way (and so other galaxies) could easily be found in "MACHO" forms of matter according to astronomers.

The term "MACHO" is typically reserved for larger objects by the way, 'larger' than say an asteroid or a moon sized objects.

That is right. The M in MACHO = Massive. Maybe you do not know what MACHOs are so:
Massive compact halo object

Massive astrophysical compact halo object, or MACHO, is a general name for any kind of astronomical body that might explain the apparent presence of dark matter in galaxy halos. A MACHO is a body composed of normal baryonic matter, which emits little or no radiation and drifts through interstellar space unassociated with any solar system. Since MACHOs would not emit any light of their own, they would be very hard to detect. MACHOs may sometimes be black holes or neutron stars as well as brown dwarfs or unassociated planets. White dwarfs and very faint red dwarfs have also been proposed as candidate MACHOs. The term was chosen whimsically, by contrast with WIMP, another proposed form of dark matter.
...
This corresponds to a negligible fraction of the dark matter halo mass. Therefore, the missing mass problem is not solved by MACHOs

(emphasis added)

I think everyone I've ever talked to besides you recognizes that at least some of the "missing mass" we're looking for could and probably is found in the form of ordinary lumps of matter that we simply cannot see with our limited technology.

Wrong: I recognize that some of dark matter is normal matter, e.g. neutrinos and MACHOs in galactic halos.

I also recognize that the Bullet Cluster, MACS J0025.4-1222 and Abell 520 observations show the majority of the ICM in those clusters is not baronic matter.

In fact I've never met anyone besides you that has tried to claim that clumpy normal matter is not present in the ICM or that 99% of the material in the ICM is ionized. There are complete stars and solar systems in the ICM. There could even be "black holes' out there too.

Wrong.
There are complete stars and solar systems between galaxies. There could even be black holes between galaxies too.
Intracluster medium

In astronomy, the intracluster medium (or ICM) is the superheated gas present at the center of a galaxy cluster. This plasma is heated to temperatures of between roughly 10 and 100 megakelvins and consists mainly of ionised hydrogen and helium, containing most of the baryonic material in the cluster. The ICM strongly emits X-ray radiation.

The intracluster stars, planetary nebulae and globular clusters
are surrounded by the ICM. They are not the ICM.

The techniques that we have used (micro-lensing) which can detect larger forms of MACHO material do tend to demonstrate that at least some of the missing mass is found in large "clumps". That technique however is physically incapable of seeing anything below a certain size because smaller objects will tend to not have any appreciable/measurable affect on the micro-lensing measurements.

That seems right.

Astronomers seem to think that that the ICM is not "lumpy stuff". I think that the reasons for this are:

• "Lumpy stuff" like stars, planets, moons, asteroids, etc. form in galaxies. They stay there except in the case of exceptional events. Some stars form between galaxies (intracluster stars). There are not 40 times as many stars between galaxies as there are in galaxies.
• "Lumpy stuff" is not dark.
  • "Lumpy stuff" emits light.
  • "Lumpy stuff" absorbs light.
  • Astronomers are really good at detecting things that emit or absorb light.

Your assertion leads to a belief that the mass in galactic clusters consists of:

• 2% in galaxies (mostly H & He).
• 14% in the ICM (mostly H & He).
• 84% in rocks in the ICM (mostly C, O and Fe).

You may (or may not) know that C, O and Fe are created in stars by fusion, i.e. H and He are converted to C, O and Fe. This means that sometime in the past the number of stars were much more than there were in these galactic clusters. So if astronomers look further away, i.e. further back into time, galaxies will (according to you) become more numerous or bigger to contain the ~40 times increase in the number of stars.

The observation that galaxies do not do this falsifies your idea.

 

[edd]

Your assertion leads to a belief that the mass in galactic clusters consists of:

• 2% in galaxies (mostly H & He).
• 14% in the ICM (mostly H & He).
• 84% in rocks in the ICM (mostly C, O and Fe).

You may (or may not) know that C, O and Fe are created in stars by fusion, i.e. H and He are converted to C, O and Fe. This means that sometime in the past the number of stars were much more than there were in these galactic clusters. So if astronomers look further away, i.e. further back into time, galaxies will (according to you) become more numerous or bigger to contain the ~40 times increase in the number of stars.

The observation that galaxies do not do this falsifies your idea.

We're back to the point that if he believes nothing in modern astronomy he's unconvinceable - if he doesn't believe in the BB, or BBN, we can't argue with him that elemental abundances began at H and He and trace Li and evolved from there in stars.

 

[Reality Check]

Another possible problem for your "lumpy stuff" idea.
If it is correct then there are about 40 times the mass of the Milky way in "lumpy stuff" between the Milky Way and neighbouring galaxies, e.g. the Andromeda Galaxy.

• The "lumpy stuff" is not MACHOs which by definition are in the galatic halo.
• The "lumpy stuff" is not black holes, neutron stars, white dwarfs or very faint red dwarfs since these are ruled out by micro-lensing.

That leaves smaller stuff as "lumpy stuff", e.g. unassociated planets, rocks or dust. If there was only a little bit of this stuff then it would not have been detected (yet!). But you are asserting that there are essentially 40 Milky Ways of "lumpy stuff" between us and the Andromeda Galaxy.

But the Andromeda Galaxy is well observed.
Why have astronomers not noticed 40 Milky Ways of "lumpy stuff"?

P.S.
Dust is unlikely in the ICM:
Far-Infrared Emission from Intracluster Dust in Abell Clusters

The ISOPHOT instrument aboard ISO has been used to observe extended FIR emission of six Abell clusters. The raw profiles of the I_(120 um) / I_(180 um) surface brightness ratio including zodiacal light show a bump towards Abell 1656 (Coma), dips towards Abell 262 and Abell 2670, and are without clear structure towards Abell 400, Abell 496, and Abell 4038. After subtraction of the zodiacal light, the bump towards Abell 1656 is still present, while the dips towards Abell 262 and Abell 2670 are no longer noticable. This indicates a localized excess of emitting material outside the Galaxy towards Abell 1656, while the behavior in Abell 262 and Abell 2670 can be reconciled with galactic cirrus structures localized on the line-of-sight to these clusters. The excess towards Abell 1656 (Coma) is interpreted as thermal emission from intracluster dust distributed in the hot X-ray emitting intracluster medium. The absence of any signature for intracluster dust in five clusters and the rather low inferred dust mass in Abell 1656 indicates that intracluster dust is likely not responsible for the excess X-ray absorption seen in cooling flow clusters. These observations thereby represent a further unsuccessful attempt in detecting the presumed final stage of the cooling flow material, in accord with quite a number of previous studies in other wavelengths regions. Finally, the observed dimming of the high-redshift supernovae is unlikely be attributable to extinction caused by dust in the intracluster or even a presumed intercluster medium.

(emphasis added)

 

[DazzaD]

Ya, well, when they use terms and energy exchange mechanisms that Alfven referred to a "pseudoscience", and they can't explain simple things that Birkeland empirically explained 100 years ago, it's very hard to believe that they have a real good grasp of plasma physics. I've yet to meet a single astronomer that has actually read "Cosmic Plasma" by Alfven.

OK. I will bite again.

I don't know of a single 'expert' in plasma physics that advocates in plasma cosmology but I did know, say, 20 or so experts in plasma physics that were following CDM models.

I took a few courses in plasma physics so know the basics required but I have also seen the in depth detailed stuff that "explains" how the Sun works. In plasma cosmology I have not seen anything even remotely approaching that level of detail, and most of the advocates of plasma cosmology that I have spoken to in the past do not even have the capability to pass an A Level maths exam (and therefore would be unable to comprehend the plasma physics required, either by Alfen or by modern cosmology).

In addition, I wonder if those who still advocate plasma cosmology do so for reasons other than directly related to the scientific method and evidence (as I understand it Alfven originally didnt like the idea of the "big bang" for reasons other than it didnt explain the data, i.e. his "religious" beliefs if you will... I may well be wrong though).

This is important to the thread as I believe the proposed mechanism by MM does not enjoy anywhere near enough "direct experimental verification here on Earth" as MM seems to prefer as does say a lambda-cdm model.

http://en.wikipedia.org/wiki/Alfvén-Klein_model#Alfv.C3.A9n_and_Klein_cosmologies

Yes... I know Wikipedia isn't exactly a scientific bible but I believe the paragraph "Comparison to mainstream cosmology" neatly fits my understanding of Plasma Cosmology.

Yes... in the 90s I did read books such as "The Big Bang Never Happened" and "Plasma Cosmology" and in them I saw very little evidence or details that match the variety of observations (e.g. galaxy formation fits, homogeneity, nucleosynthesis, and, for me the most interesting, the existence of the cosmic microwave background - in detail, not a hand waving argument that "radiation will be emitted in annihilations").

This is important to this thread in my opinion because the refusal to accept the evidence given by surveys and experiments, regardless of what your pet theory is, is holding us back in some of the details here.