Lambda-CDM theory - Woo or not?

[Reality Check]

Nope. That's exactly why I hold no set beliefs about large scale cosmology. The concept "I don't know and maybe never will know" is just fine by me. I do like Alfven's bang theory, but I'm not emotionally attached, nor would I necessarily say it's the "best" theory I've ever seen.

You have not heard of the scientific method.
This is the basis of modern science.
Basically a theory that fits the evidence is considered to be correct until new evidence falsifies it. The falsified theory is eventually replaced by another theory that explains the old evidence and the new evidence.

Alfven's bang theory made predictions for the X-ray background (falsified) and could not explain the istropy of the CMB. That is why so few cosmologists treat it as correct.

Your theory doesn't fit the data any better than Alfven's theory. Aflven's theory doesn't claim to "know" the actual age of the original physical universe.

BBT does fit the data a lot better than Alfven's theory, e.g. the power spectrum of the CMB is not addressed at all by Alfven's theory.

False. You *ASSUMED* this part completely.

False. You *IGNORED THE EVIDENCE* for this part completely.
When we detect matter acting in 2 different ways in colliding galactic clusters under the same forces then the matter is two different kinds of matter.

I'm not ignoring it at all. Birkeland predicted that ions and electrons would make up more mass than all the stars in the universe. It's not surprising to me in any way.

Look at the diagram again and do a little research. Actually you will not so I will tell you: The surface mass density of the IGM is 0.01 gm/cm squared (from memory). This is 1% of the the background in the diagram.

So have another look:
Of course you are ignoring the fact that there is dark matter (in fact most of it) between galaxies as this surface mass density diagram shows.http://scienceblogs.com/startswithab...on0024_500.jpg

What this shows you is that yes, there are spikes where the individual galaxies are. But the cluster is dominated by this giant spherically-distributed mass that's present everywhere, both where there are galaxies and where there aren't. And that has got to be dark matter.

Why does it do that if not because it's "dustier" than you originally thought? Maybe because there's more iron than you thought? Suddenly the same number of atoms absorbs double the light? How does that work exactly? Why should I *STILL* trust any of your numbers after we know that the universe is twice as bright as you thought?

It is either dustier or there is more. So what?
ETA: The actual paper (here is its abstract) is about interstellar dust grains - not individual atoms in the ISM. So the cause of the blocking of the light is possibly a different distribution of grain size than previously thought.

What effect do you think the "brightness of the universe" has?
Are you under the impression that the brightness of galaxies are commonly used to measure their distance? You would be wrong. There might be an effect on the Tolman surface brightness test. Otherwise it is just an update to the magnitudes in the catalogs.

If your argument is this one result makes you distrust all numbers in astronomy then you are being especially ignorant of science. All numbers in science change as more evidence is collected. That is how science works.
For example the age of the Earth has been recalculated many times. Are you going to throw away geology because of this?

Now please cite the paper that states that the ISM is denser than currently measured.

 

[Ziggurat]

That is false. He never tried to detach his theory from GR, nor to explain everything from GR. It's completely compatible with GR.

I don't care what he tried to do. He never showed that his cosmology is consistent with GR. He couldn't, because it's not. Whether he understood this, was mistaken about it, never considered it, or ignored it, I don't know and don't care. His cosmology cannot be reconciled with the Einstein field equation.

So what? What makes you think you *SHOULD* try to stuff the EM field into GR in the first place?

Electromagnetism fits rather naturally into General Relativity (a conclusion which should be obvious given the development history of the subject). No "stuffing" is required. And you're the one who is (incorrectly) claiming that inclusion of electromagnetism can change the conclusions of GR.

No, they are not mutually exclusive. They are mutually *INCLUSIVE* to GR and MHD theory. You're the one that is being "exclusive" as in being exclusively emotionally attached the the idea that GR is everything there is to know about the universe or that everything should revolve around GR.

You can keep making this claim, but it's never going to be true. You cannot make Alfven's cosmology a valid solution to the Einstein field equations. It doesn't matter whether or not "GR is everything": if you can't match the field equations, it's inconsistent with GR. No ifs, ands, or buts.

No. You get either a bang *OR* a crunch or some other force must be involved.

Nope. Observations preclude an infinitely old collapsing universe, and other forces can only stop collapse if they match the form of a cosmological constant with an exact value. Which you have disavowed as a possibility. And which are also precluded by observation.

The fact you excluded the crunch part only shows YOUR ignorance, not mine.

Not so. It only shows that I didn't want to waste my time on such a trivially falsified option.

That is simply a false dichotomy fallacy. Alfven never *EXCLUDED* GR, nor did he ever suggest there was anything wrong about GR. You make that up.

Doesn't matter. His ideas are still inconsistent with it, whether he intended or understood that inconsistency or not.

 

[Tubbythin]

Still, I can't be sure that every star, larger or smaller than our own sun is necessarily unaffected by solar composition. In fact, I couldn't necessarily even be sure that all stars of our own sun's size necessarily have the same total mass. A lot would depend on how the elements arrange themselves internally as well as externally. We can't even see planets yet directly, so anything small in size is going to be "dark matter".

Planets are much fainter than the stars they orbit. That's why they are difficult to spot.

For all I know the universe is eternal and we all agree it's already been here for billions upon billions of years. I don't see how that really helps your argument.

Well, if wikipedia is to be believed. By billions upon billions I should have said ~ 10³² years. You're probably the onlyone participating who might believe the Universe is that old.

IMO all the lensing data demonstrates is that it's likely that the answer lies in some form of "missing mass", rather than perhaps MOND theory.

So you disagree witht he conclusion in the papers RC linked to. Can you tell us what the groups did wrong?

It's thicker than we realize evidently. I suppose that is why the galaxies are now thought to be twice as bright as before.

And?

Please elaborate for me a bit.

Don't have time at the minute. Read RC's papers he linked to.

I just meant that unless electrons somehow makeup a huge percentage of the universe in terms of mass, I would expect current techniques could otherwise identify other types of charged ions already. Maybe I'm giving them too much credit. If however electrons make up a significant portion of the ISM, it might be a lot trickier to locate that mass.

Electrons are probably the easiest particles to identify.

I guess I'll wait till I hear you explain the weak lensing thing.

I don't have time at the minute. Try reading the papers.

Well, the concept of 'viable' here seems to be rather subjective. I really don't see how it's "viable" to "make up" a new form of matter in an ad hoc manner and start assigning it 'properties' based on what we "need" it to do to fix our otherwise dead theory.

Erm. Well for starters it isn't ad hoc.
Its as viable as "making up" extra quarks when the three quark model couldn't explain all the observations. Its as viable as adding the displacement current term to Ampere's law. Its as viable as "making up" the photon to describe the photoelectric effect. They are all falsifiable solutions to explain unexpected behaviours in observations. I don't see you rejecting the existinence of the photon though. All calling its properties "ad hoc". The benefit of 20-20 hindsight is a wonderful thing.

I'd be thrilled to entertain the idea of you could demonstrate it actually exists in nature, and has the "properties" you suggest. If not, it seems like you're fudging the numbers and making up magic properties to fit the math formulas.

If it seems like that then you haven't been looking closely enough.

Unidentified mass or matter is find by me, but the term "dark" is too vague and it now has "mythical" qualities being assigned to it.

How is "dark" vague? Seems to fit the bill quite nicely imo. The fact that you can't seem to concentrate properly when its given a name other than the one you would like it to be given is nobodies problem but you're own. And if all you can do is argue over semantics then you really are stuggling.

For instance, MACHO forms of 'dark matter' have no special "properties" required. The properties assigned to such forms of DM come straight from physics and controlled experiment. Nobody just "made it up" as they went.

Got a MACHO in your lab have you?

That puts "real" limits on it's usefulness of course, but that is life. SUSY oriented forms of "DM" however are purely hypothetical.

So was the photon, so was the gluon, so was the Z boson, so were the W bosons, so was the top quark. They were all hypothetical once upon a time.

The "properties" being assigned to them are not something we have learned via experimentation, but are "assumed" based more on "need" than upon direct examination.

Nobody is "assuming" anything. People are observing AND experimenting. And this gives us restrictions on what the particles can be. Much like we had restrictions on the top quark long before a top quark was ever created in the lab.

The term is now far to vague and far too mystical.

The only one talking about mysticism is you. And again, you're just arguin over semantics.

You're assuming a lot of things. starting with the idea that your mass estimates were or should be accurate.

Its not an assumption. An assumption would be doing something once and then not repeating it or trying a different method. Or not doing it at all.

You can only "find" where lensing occurs. [\Quote]
Nope. The rotation curves tell us where it is pretty well.

Unless MOND theory applies?

MOND cannot explain the bullet cluster.

The only "property" it exhibits is "missingness". You might "imagine" it has other properties but you cannot demonstrate a single one of them in a controlled experiment.

Of course we can. For a start it cannot radiate much. You don't need to make it in a lab to see that?

No, the study of matter is something I have a great deal of respect for. I'll therefore let you use any known form of matter, and use any "property" you can think of that has been lab tested.

How very kind of you.

It's when you try to go outside the lab, and try to claim you found proof of some kind of exotic material that
I will complain.

Complain all you want. Nobody is going to tak ethe slightest bit of notice of you if the best you can manage is basically "I don't like the name".

Sure, but MOND theory can. You can't use that as final argument. Sure, maybe I'll let you claim you know where to find it by these rotation curves,

MOND cannot explain the bullet cluster. Or at least not as far as I've seen any MOND theory.

but you still haven't found it, and you still can't say for sure what "form" it takes. It's still just "unidentified flying mass".

That's what makes science interesting, moving in to the unknown.

There are not "multiple independent experiments" or any controlled experiments to verify properties like invisibility

Its there. We can't see it. Therefore its invisible.
And by the way, the neutrino is invisible.

or the ability to pass right through ordinary matter,

What, like the neutrino?

or the ability to have no effect at all on photons,

You mean like the neutrino?

the ability to "decay" into something leaving gamma rays or x-rays or whatever the claim of the day might be.

You mean the things that make the theories falsifiable?

All of these things are written about and discussed and published in "dark matter" papers. That's pretty "weird" and "made up" if you ask me.

Its weird that some exotic particle isn't really all that exotic after all?

Even if you do eventually find a SUSY related form of matter (a long shot at this point), it may decay into ordinary matter in milliseconds for all you know.

Indeed (though not in the MSSM form of SUSY). I thought you were trying to argue before that these things weren't falsifiable. And yet now you seem to be suggesting ways of falsifying DM particles == SUSY particles. Your line of argumeent is truly baffling.

I respect you enough to wait till you explain how anything is ruled out by lensing observations. I see no way for you to decide what form of matter is involved based on distant lensing observation. All that could possibly do is tell you roughly where the matter is located. It could still be in any "form" like a MACHO variety form of DM.

Read RC's papers.

Doesn't it make you the least bit uncomfortable making up the properties just to make it fit some math formulas?

Nope. That's what happened with most of the standard model. Just look how successful that's been (try counting all the Nobel prizes).

Shouldn't we look to particle physics here and wait and see if we even find SUSY particles

We are. "Large Hadron Collider" mean anything to you?

and see what properties they may actually posses *before* we simply "assign" them based entirely on "need"?

No harm in working out where is best to look. It beats looking at things in a random, haphazard manner.

How exactly can we do that? We don't seem to find evidence of them being destroyed or created inside of our planet as expected by some WIMP papers, and I don't see any evidence of them in solar emissions either. How exactly do we falsify them since we've never seen them in a controlled experiment and we find no evidence of them in the ways we expected to?

Try reading the paper.

How?

Try reading the paper.

I have no personal problem with you using any form of neutrino that you have identified in nature via controlled experimentation. I'll give you plenty of latitude on that one to be sure because I know that some types of neutrino detection are possible.

Well thank you. Sadly I'm rather busy with other things.

The paper that edd linked to yesterday also *PRESUMES* that the galactic mass measurements are correct just like every other DM theory on the planet. Until or unless you can rule out dust, dead stars etc, I don't really see how any of the exotic forms of matter even warrant serious consideration.

This is irelevant. Your claim was that DM candidates were unfalsifiable. I pointed you in the direction of this paper in order that you could see that you were wrong. You have now chosen to pretend we were referring to this paper for some other reason. I'll take that to mean that you have realised that you cannot justify your previous claim that "nothing is falsifiable".

 

[Reality Check]

Micheal Mozina, you seem to be obsessed about calling dark matter "missing matter".
This is wrong. Dark matter is "measured matter" that just happens to not interact with electromagnetic forces (is dark).

You would have been correct in 1933 when Zwicky found that the movement of galaxies in galactic clusters meant that there was a lot of unseen matter (he calculated this as 400 times the visible matter in the Coma Cluster). Astronomers were expecting that this would turn out to be ordinary matter that they just could not see with their current apparatus.

You would have been correct in late 1960s and early 1970s when Vera Rubin showed that the rotation curves of galaxies suggested that there was unseen matter.

You are wrong now since the weak gravitational lensing technique over the last 10 years has measured the actual distribution of matter in galactic clusters, i.e. measured bith normal matter and dark matter.

You are totally wrong now since there have been 2 observations of dark matter separating from normal matter in galactic cluster collisions.

 

[Michael Mozina]

You are totally wrong now since there have been 2 observations of dark matter separating from normal matter in galactic cluster collisions.

So? You still haven't actually "seen" it have you? You still haven't identified the matter in any way. You've only seen some lensing patterns are that indicative of and consistent with the idea that there is mass that is located in places where you can't see any mass. It's still "missing" and you haven't "seen" it directly. That much was known from the start based on the rotation patterns. The could probably work out where they may expect to find that mass too from only the rotation patterns.

The point I've been trying to make is that your lensing data does suggest to me at least (some may still disagree) that there is in fact additional mass inside those distant galaxies that you have yet to identify. This sort of puts MOND theory on the back burner in that respect. Like I said, some MOND fans might not agree, but hey, who cares what I think anyway?

There is however an important difference between proposing a know form of matter like a neutrino as being responsible for this mass vs. claiming it is made up of invisible gnomes. Whereas we can all agree that there is "controlled" experimental evidence that neutrinos exist, none of your SUSY particles have been verified nor have any of their "properties" (like longevity) been demonstrated. You're welcome to claim that the missing matter (unidentified matter if you prefer) is made of any know form of matter. If however you make extraordinary claim about the type of matter that exists "somewhere out there", I will expect "extraordinary" evidence to support that idea from the rest of science. You're way out on a limb on the notion of "non-baryonic' exotic matter.

Frankly the DM thing is the least of your worries. Your make believe "dark energy" was purely an ad hoc assertion that is absolutely, positively impossible to falsify. The same is true of inflation. Those two metaphysical bad boys are *WAY* more of a problem than DM. DM could be resolved any number of ways that are entirely "scientific". Hell, you could even get lucky in future collider experiments for all I know. I kind doubt it mind you, but even I would admit that it's not beyond possibility that you may some day find evidence for *SOME* new form of matter. Now mind you, it may not be long lived enough to prop up your theory, but hey, anything is possible.

DE and inflation however we literally made up in human imagination and there is no way on Earth to verify or falsify these ideas.

 

[Michael Mozina]

Planets are much fainter than the stars they orbit. That's why they are difficult to spot.

Sure, but dead stars would also be difficult to spot. Anything that isn't emitting a lot of light is going to be missed completely. The dust in the galaxies and in between galaxies could also block (evidently does) more light than you realize and some of these stars may be much larger than you realize. There are many possible reasons why these mathematical models may be incorrect.

Well, if wikipedia is to be believed. By billions upon billions I should have said ~ 10³² years. You're probably the onlyone participating who might believe the Universe is that old.

I simply don't profess to know the age of the universe at all. I know it is many billions of years old at the very least.

So you disagree witht he conclusion in the papers RC linked to. Can you tell us what the groups did wrong?

Well, "wrong" in what sense? I see nothing wrong with the basic lensing theories, nor anything wrong with deducing that there is some form of matter that is responsible for that lensing process. I see no evidence that any of that matter is 'non-baryonic' with the exception of neutrinos, which we all seem to agree is one form of non-baryonic matter that actually does exist in nature.

Electrons are probably the easiest particles to identify.

Yes and no. Yes, they create patterns and magnetic fields in plasma and they scatter light too, but that presupposes that you *WANT* to find them, and you realize what you're looking at. When they spot a 'slinky' in space, that *SHOULD* make them realize that electrons and current flow are involved in the process, but they didn't say a word about it. It's all "magnetic yada yada yada", and not a mention of a single electron.

Erm. Well for starters it isn't ad hoc.
Its as viable as "making up" extra quarks when the three quark model couldn't explain all the observations.

There are no more particle physics interactions that we do not profess to "understand" in ordinary (standard) particle physics. SUSY theory is not required to explain any observation from the study of particles.

The benefit of 20-20 hindsight is a wonderful thing.

Everything on your list are things we can physically test for and that were typically proposed due to something seen in a *CONTROLLED* test that could otherwise not be explained. Compare and contrast that to pointing at distant objects in the sky and slapping on behaviors to new forms of matter only so they will fit into the theory. It's completely different.

I'm going to skip a bit of the redundant or unimportant parts by the way.

Got a MACHO in your lab have you?

A MACHO mass form makes no real extraordinary claims. We already know we've found planets we could not see with our older technology and we all know we'll see more when the technology improves. There is nothing "extraordinary" in that proposal. If however I claimed it was due to invisible friends, that would be an extraordinary claim and would require extraordinary supporting evidence.

So was the photon, so was the gluon, so was the Z boson, so were the W bosons, so was the top quark. They were all hypothetical once upon a time.

Each of these things was proposed due to what was learn in *CONTROLLED* tests.

Nobody is "assuming" anything. People are observing AND experimenting. And this gives us restrictions on what the particles can be. Much like we had restrictions on the top quark long before a top quark was ever created in the lab.

But there is nothing missing from standard particle theory with the exception of the Higgs. Everything else has been seen and identified and accounted for now. There's no need for additional particles or any verified evidence for them.

MOND cannot explain the bullet cluster.

Fine. All that demonstrates is that there is matter in these galaxies that your theories did not account for. I still have no idea what that material is made of.

Of course we can. For a start it cannot radiate much. You don't need to make it in a lab to see that?

My "missingness" comment was supposed to by humorous by the way. Ok, fine it doesn't radiate much in the way of photons. We'll go that far.

I'm going to stop here for now so I can get something to drink.

 

[Reality Check]

So? You still haven't actually "seen" it have you? You still haven't identified the matter in any way. You've only seen some lensing patterns are that indicative of and consistent with the idea that there is mass that is located in places where you can't see any mass. It's still "missing" and you haven't "seen" it directly. That much was known from the start based on the rotation patterns. The could probably work out where they may expect to find that mass too from only the rotation patterns.

Wrong yet again.
Astronomers have literally seen it. It has been seen directly for over 10 years in many observations.
Gravitational lensing is a standard technique in astronomy to measure the density of galactic clusters. It is almost as standard nowadays as using a telescope (perhaps a better comparison are the various interferometers in operaiton such as the European VLBI Network sine there is a lot of post-processing of the data).

The point I've been trying to make is that your lensing data does suggest to me at least (some may still disagree) that there is in fact additional mass inside those distant galaxies that you have yet to identify. This sort of puts MOND theory on the back burner in that respect. Like I said, some MOND fans might not agree, but hey, who cares what I think anyway?

The point that you have totally missed is seen when you look at the actual distribution of matter in a galactic cluster. Here is the picture again. This time look at it and note

1. The minimum density of the spaces between the galaxies is a couple of orders of magnatude above that of the IGM.
2. The enourmous bulge in the middle, again mostly outside of the galaxies.

There is however an important difference between proposing a know form of matter like a neutrino as being responsible for this mass vs. claiming it is made up of invisible gnomes. Whereas we can all agree that there is "controlled" experimental evidence that neutrinos exist, none of your SUSY particles have been verified nor have any of their "properties" (like longevity) been demonstrated. You're welcome to claim that the missing matter (unidentified matter if you prefer) is made of any know form of matter. If however you make extraordinary claim about the type of matter that exists "somewhere out there", I will expect "extraordinary" evidence to support that idea from the rest of science. You're way out on a limb on the notion of "non-baryonic' exotic matter.
...snipped usual DE/inflation rant...

No one states that dark matter is made of invisible gnomes. Where did you get that dumb idea ?

Nobody knows what dark matter is made of. We can measure its properties and that tells us what is can and cannot be.
Dark matter is observed to act differently to baryonic matter in galactic collisions. That is the "extraordinary" evidence that you demand.
These observations are evidence that dark matter is nonbaryonic matter.

And there you go again with your silly obsession with "controlled" experimental evidence .
The uncontrolled experimental evidence (i.e. observations) that the universe provides us is just as good as the controlled experimental evidence that we can produce. The only difference is the amount of control - more control = more ability to explore the parameters of the experiment.
It would be very nice to be able to collide galactic clusters together in a controlled manner - maybe you can put a proposal into NASA!

 

[Wangler]

13.7 billion years is not assumed. It is a calculation from the WMAP data using the BBT.

From your link:

"Calculating the age of the universe is only accurate if the assumptions built into the models being used to estimate it are also accurate. This is referred to as strong priors and essentially involves stripping the potential errors in other parts of the model to render the accuracy of actual observational data directly into the concluded result. Although this is not a valid procedure in all contexts (as noted in the accompanying caveat: "based on the fact we have assumed the underlying model we used is correct"), the age given is thus accurate to the specified error (since this error represents the error in the instrument used to gather the raw data input into the model)."

If you need to assume the model used is correct, it seems to me that the age determined is "assumed".

If "assumed" is too strong word, perhaps "inferred" would be a better description?

MM, would you be happy if it was stated that the age of the universe is inferred to be 13.7 billion years, based upon models derived from observational evidence?

 

[brantc]

"All the time" starts to lose meaning when you reach t=0.

LOLOLOLOLOL

Freaking classic!!!!

 

[Reality Check]

From your link:

"Calculating the age of the universe is only accurate if the assumptions built into the models being used to estimate it are also accurate. This is referred to as strong priors and essentially involves stripping the potential errors in other parts of the model to render the accuracy of actual observational data directly into the concluded result. Although this is not a valid procedure in all contexts (as noted in the accompanying caveat: "based on the fact we have assumed the underlying model we used is correct"), the age given is thus accurate to the specified error (since this error represents the error in the instrument used to gather the raw data input into the model)."

If you need to assume the model used is correct, it seems to me that the age determined is "assumed".

If "assumed" is too strong word, perhaps "inferred" would be a better description?

MM, would you be happy if it was stated that the age of the universe is inferred to be 13.7 billion years, based upon models derived from observational evidence?

The problem is that MM believes that only experimental evidence from controlled experiments is valid. Thus the uncontrolled observations of the CMB (we cannot switch the CMB on or off) are wrong !

It is better to say that the WMAP calculation of the age of the universe is inferred to be 13.73 +/- 0.12 billion years, based upon models derived from observational evidence.
And

The age of the universe based on the "best fit" to WMAP data "only" is 13.69±0.13 billion years.

 

[Reality Check]

One wonders if MM wuld accept a detection of dark matter by Fermi (Could Fermi detect dark matter within a year?).

 

[Michael Mozina]

One wonders if MM wuld accept a detection of dark matter by Fermi (Could Fermi detect dark matter within a year?).

Well, let's look at what they are trying to detect, shall we?

The Fermi Gamma-ray Space Telescope could detect the telltale signs of dark-matter annihilation in as little as a year, if calculations by UK and US astrophysicists prove correct.

The calculations, which are the first to take into account the relative velocities of dark-matter particles, suggest that dark-matter annihilation is many times more prevalent than has been predicted before.

So evidently they are simply *ASSUMING* another "property" of DM, namely annihilation. Did they actually demonstrate that DM annihilates in a controlled experiment anywhere? Oooooops. No, they simply came up with another alleged "property" of DM so they can slap some math on the idea and point at the sky. Sorry, that's never going to be a real "controlled" experiment. Here however is my very favorite part:

Past simulations of dark matter for a galaxy like our own Milky Way have always predicted annihilations to be so rare that telescopes would barely be able to detect the resultant gamma-rays and other particles above the universe’s background. Last year, however, the European satellite PAMELA and the international balloon-borne experiment ATIC recorded excesses of positrons and electrons respectively, hinting at dark-matter annihilation.

So in other words, the old "predictions" expected to see virtually nothing, but now that they launched a balloon and found annihilation signatures, they have every intent of now attributing these events to something that they have never shown to even exist, let alone that it emits gamma rays. This is pure "made up" math formula and another perfect example of "point and the sky and add math" exercise. Never mind the fact that Alfven predicted annihilation signatures due to matter/antimatter reactions and we happen to see these same signature is large "clouds" in the center of even our own galaxy. Never mind the fact that even our own sun and the even the Earth create such signatures. No matter what, anything they now see in terms of matter/antimatter annihilation signals, it will necessarily now be considered evidence that "Dark matter did it".

The article continues....

Kuhlen, together with Piero Madau at the University of California in Santa Cruz, US, and Joseph Silk at the University of Oxford, UK, decided to see whether these observations could be explained if dark-matter annihilation rates were boosted by an effect known as the Sommerfield enhancement.

Now this statement is really funny. Not only do they not have any evidence that annihilation actually takes place in "dark matter", they now intent to "boost" the non-demonstrated rate of annihilation using an enhancement process that they have also never tested in any way. In other words, we're simply adding math till we get what we are after, not because the properties of this form of matter have been identified and we know for a fact that the effect is enhanced under specific conditions. It's purely an artificial ad hoc assumption that the Sommerfield enhancement even applies. It's purely a fictional relationship.

In this effect, a long range force

A long range force? Like what?

— which would manifest as either a conventional weak-force boson or a new force carrier

Oh, a THIRD and FORTH assumption have now been made as to what it will manifest as, and it may involve a whole *NEW* carrier

More ad hoc assertions completely devoid of empirical support.

— increases the rate of annihilations when the dark-matter particles are moving slowly.

Oh, another ad hoc assertion. It has to now be moving "slowly".

Kuhlen’s group applied several different models of Sommerfield enhancement to a simulation of the Milky Way that contained more than a billion particles to see how the gamma-ray flux would be affected.
Seeing subhaloes

For the greatest enhancement, the researchers found that more than 400 subhaloes would be detectable to the Fermi space telescope — which was launched in June 2008 — after one year, and after ten years the figure would rise to over 900. But even for the most conservative model, the researchers found that after a year five subhaloes would be visible.

The news is likely to excite astrophysicists, many of whom have spent decades searching for dark matter’s smoking gun.

So now any form of annihilation signatures we can't identify are now going to be attributed to, and assumed to be related to, "dark matter". This whole relationship series of "properties" was contrived in a completely ad hoc manner. There is no observed annihilation signature from "dark matter". Period. There is no effect that is known to increase that rate because it's never been show to occur even once, let alone more than once. This whole line of reasoning is purely a logical fallacy of begging the question from beginning to end, not to mention the fact it's based upon a half dozen or so non sequiturs.

A) If dark matter exists
B) and it lives long
C) and it creates annihilation signatures
D) and the Sommerfeld force applies
E) and we throw in a whole new force of nature just for kicks
F) and DM moves "slowly"
G) then we can match these gamma ray observations
H) therefore A)-G) must be true.

 

[Michael Mozina]

Wrong yet again.
Astronomers have literally seen it.

If you have literally seen it then it isn't "dark matter" by definition.

It has been seen directly for over 10 years in many observations.

No. At best you could say it's been "inferred" from lensing data for 10 years.

Gravitational lensing is a standard technique in astronomy to measure the density of galactic clusters.

It's not allowing you to "see" dark matter directly. At best it an *INDIRECT* kind of evidence. You aren't seeing it, your seeing it's EFFECT on photons.

You can't even tell the difference between a *DIRECT OBSERVATION* from an inferred presence that is derived from lensing data.

 

[Michael Mozina]

From your link:

"Calculating the age of the universe is only accurate if the assumptions built into the models being used to estimate it are also accurate. This is referred to as strong priors and essentially involves stripping the potential errors in other parts of the model to render the accuracy of actual observational data directly into the concluded result. Although this is not a valid procedure in all contexts (as noted in the accompanying caveat: "based on the fact we have assumed the underlying model we used is correct"), the age given is thus accurate to the specified error (since this error represents the error in the instrument used to gather the raw data input into the model)."

If you need to assume the model used is correct, it seems to me that the age determined is "assumed".

If "assumed" is too strong word, perhaps "inferred" would be a better description?

MM, would you be happy if it was stated that the age of the universe is inferred to be 13.7 billion years, based upon models derived from observational evidence?

I'd be happier sticking with the authors explanation about the "assumptions" that are being made.

 

[Michael Mozina]

Nobody knows what dark matter is made of.

Then how do you know any of it is "non-baryonic" other than say perhaps the neutrino mass?

We can measure its properties and that tells us what is can and cannot be.

No, you can't "measure" it from a point at the sky exercise. You'd have to have a controlled test to "measure" any physical properties of matter. You can't do that if you can't even see it from a huge distance.

Dark matter is observed to act differently to baryonic matter in galactic collisions.

No it doesn't. How does it act "differently" in any way?

That is the "extraordinary" evidence that you demand.

It's just an "extraordinary claim".

These observations are evidence that dark matter is nonbaryonic matter.

No, they are not. All you know is that the mass that is there causes photons to change their paths. That is all that you know from this data. You literally made up the rest of the "properties" you're assigning to the material.

And there you go again with your silly obsession with "controlled" experimental evidence .

Like science as a whole doesn't put value on that process?

The uncontrolled experimental evidence (i.e. observations)

Observations are not "uncontrolled experiments". They are "uncontrolled observations".

that the universe provides us is just as good as the controlled experimental evidence that we can produce.

Absolutely false. How did you intend to demonstrate that dark matter annihilates? Let me guess? You're going to skip that part entirely and just *ASSUME* it's true? How about that new force of nature they threw in there for fun? That's good too?

The only difference is the amount of control - more control = more ability to explore the parameters of the experiment.

You can't determine cause/effect relationships in distant uncontrolled observations. You can't for instance demonstrate that DM annihilates and generates gamma rays. That is purely an ad hoc assertion, and no amount of pointing to the sky at gamma rays is going to change that fact.

It would be very nice to be able to collide galactic clusters together in a controlled manner - maybe you can put a proposal into NASA!

I'd be happy seeing them generate even a *SINGLE* annihilation event from DM in a controlled experiment. That's never happened. Now they intend to point at the sky a gamma rays, they slap some math to the side of a half-dozen different non sequiturs and then you expect me to simply accept this nonsense? Please.

 

[Reality Check]

Then how do you know any of it is "non-baryonic" other than say perhaps the neutrino mass?

Since you are too lazy to look this up:

The most direct observational evidence to date for dark matter is in a system known as the Bullet Cluster. In most regions of the universe, dark matter and visible material are found together, as expected because of their mutual gravitational attraction. In the Bullet Cluster, a collision between two galaxy clusters appears to have caused a separation of dark matter and baryonic matter. X-ray observations show that much of the baryonic matter (in the form of 107–108 Kelvin gas, or plasma) in the system is concentrated in the center of the system. Electromagnetic interactions between passing gas particles caused them to slow down and settle near the point of impact. However, weak gravitational lensing observations of the same system show that much of the mass resides outside of the central region of baryonic gas. Because dark matter does not interact by electromagnetic forces, it would not have been slowed in the same way as the X-ray visible gas, so the dark matter components of the two clusters passed through each other without slowing down substantially. This accounts for the separation. Unlike the galactic rotation curves, this evidence for dark matter is independent of the details of Newtonian gravity, so it is held as direct evidence of the existence of dark matter

Or perhaps you do not understand the explanations given in the links, here is my attempt to explain:

Consider a galactic cluster. It has a lot of gas in the intergalactic medium.
Consider two galactic clusters that are colliding.
What happens if the gas in the clusters is a mixture of baryonic and nonbaryonic matter? Baryonic matter interacts with with all the 4 forces. Nonbaryonic matter does interacts weakly (or not at all) with electromagnetism.

The baryonic matter in each cluster will be colliding and interacting electromagnetically. This will form shock waves, slow the gas up and heat up the gas. The heated gas will emit X-rays. Thus the Chandra X-ray observatory will observe this heated baryonic matter.

So astronomers pointed Chandra at the Bullet Cluster. They saw the shockwave and heated gas. This means that they had measured the position of all of the gas that had interacted electromagnetically, i.e. baryonic matter.

Most of the nonbaryonic matter will pass through the baryonic and nonbaryonic matter.

The question is what the distribution of all types of matter is in the Bullet Cluster?

There is another technique to measure the distribution of matter in a galactic cluster - weak gravitational lensing. This was done with the Bullet Cluster. The result was that the majority of the mass was actually concentrated to either side of the heated gas.

So we have

• The baryonic matter that has slowed down and is in the center of the cluster.
• Nonbaryonic matter that has not slowed down and is to either side of the heated gas.

This is direct evidence that the majority of mass in galactic clusters is nonbaryonic matter. This matter just happens to not emit light (it does not interact electromagnetically). Thus we call it dark matter.

And then there is the other observation.

ETA
If you do not like the "mixture of baryonic and nonbaryonic matter" starting point then work the logic backward:

1. We have the observation that most of the matter is to each side of the heated gas.
2. To get there it must have not interacted electromagnetically (or not much) with the gas in the middle when it passed through it.
3. This means that the matter is nonbaryonic.

ETA2
Even simpler:
Big blob of stuff A.
Big blog of stuff B.
Blob A hits blob A.
If the stuff is all the same stuff then the result is another blob of stuff.
If the stuff is a mixture of two kinds of stuff, one of which interacts weakly with the other, then the result is 3 blobs since the weakly interacting stuff passes through the other stuff.
We see 3 blobs.

ETA3
The posibility that the weakly interacting stuff is MACHOs is small since they have been effectively ruled out by observations.

 

[tusenfem]

Your theory doesn't fit the data any better than Alfven's theory. Aflven's theory doesn't claim to "know" the actual age of the original physical universe.

Well, this is a bit of semantical play. Because Alfvén writes in Worlds-Antiworlds in e.g. the caption of Figure 4c on page 17:

The primordial state is assumed to be a very large, very diluted cloud wiech by gravitation to contracts towards the center. Its different parts pass each other millions of light-years apart, after which they rush out again. The minimum size was reached 10 billions years ago.

Which sounds like a "bouncing" universe, which he describes on page 23:

According to the second class [my note: i.e. the non Big Bang class] of explanations, a primeval state of extremely tenuous matter is postulated. Under the influence of gravity, this giant cloudl of gas begins to contract. when it reaches a diameter of perhaps one billion light-years, it expands once again and the galaxies move outward as they are doing now.

Therefore, one can say that according to Alfvén's model the current universe can be estimated to be on the order of 10 billion years old, as that is when the expansion from a very small cloud began.

Indeed, it does not say where or when the "primeval tenuous gas cloud" came from, but for all purposes, the start of the expansion can be taken as the age of the visible universe in this model.

And to be nitpicky, maybe in the first quote of Alfvén I should have written is *ASSUMED* to be.

I'm not ignoring it at all. Birkeland predicted that ions and electrons would make up more mass than all the stars in the universe. It's not surprising to me in any way.

Can we please start to get evidence of the claims by Birkeland. Can you start giving the page numbers of his book where he makes these claims? And please do the same in the electric universe thread, because you make loads of claims that Birkie said this and Birkie calculated that, but when one finally finds something that resembles your claim, it turns out to be different as you say. So please start quoting Birkeland and don't just say "read the book" or "it's in the book", quote page numbers.

 

[tusenfem]

Alfven's bang theory made predictions for the X-ray background (falsified) and could not explain the istropy of the CMB. That is why so few cosmologists treat it as correct.

There is an old paper by Hunter (1967) discussing the Alfvén-Klein cosmology, published in MNRAS. Old, so no new stuff in there, so this should appeal to MM, who seems to like old stuff better than new stuff. The abstract by Hunter reads:

An approximate treatment fo the Alfvén-Klein metagalxy is presented with a view of determining whether this cosmology could account for the background black-body radiation in the Universe. it si shown that no non-rotating cosmological model of the type would have been able to establish a black-body radiation field at the epoch of minimum radius and then re-expand to infinity.

Here is the paper by Alfvén. Unfortuantely, I have no link to the Alfvén & Klein paper.

Then at the end Hunter concludes:

In the previous sections it has been shown that no non-rotating metagalactic model of the type proposed by Alfvén and Klein would have been able to establish a black-body radiation field at the epoch of maximum compression and re-expand to infinity. It is therfore conclude that, if general relativity is correct and if the observed background radiation really represents a cosmological black-body radiation field, then the cosmology of Alfvén and Klein cannot describe the observed Universe statisfactorily. This conclusion can be altered only if ic can be shown that rotation markedly influences the nature of gravitatinal collapse in general relativity^* or if alternative mechanisms can be suggested for producing a background, black-body radiation field in Alfvén and Klein's metagalaxy.

^* In this connection, Penrose (1965) has shown that departures from spherical symmetry (such as those which would be introduced by rotation) cannot prevent gravitational collapse from continuing once an object falls within its Schwartzschild radius, provided that the departures are not too large.

 

[Reality Check]

Can we please start to get evidence of the claims by Birkeland. Can you start giving the page numbers of his book where he makes these claims? And please do the same in the electric universe thread, because you make loads of claims that Birkie said this and Birkie calculated that, but when one finally finds something that resembles your claim, it turns out to be different as you say. So please start quoting Birkeland and don't just say "read the book" or "it's in the book", quote page numbers.

I suspect that MM is referring to page 720 in the book where Birkeland states:

It seems to be a natural consequence of our points of view to assume that the whole of space is filled with electrons and flying electric ions of all kinds. We have assumed that each stellar system in evolutions throws off electric corpuscles into space. It does not seem unreasonable therefore to think that the greater part of the material masses in the universe is found, not in the solar systems or nebula, but in "empty" space.
Let us see how thickly we should have to imagine iron atoms, for instance, distributed in space between the sun and the nearest star, a Centauri, if, in a sphere with the distance 4.4 light-years as radius we assumed a mass equal to that of our solar system to be evenly distributed.
The mass of our solar system may be estimated at 2 X 10^33 grammes (see Young, General Astnonomy, pp. 97 and 603). The distance to a Centauri is 4 X 10^18 centimetres, and the volume of the said sphere about the sun would thus be 2.7 X 10^50 cubic centimetres.
If the mass of our solar system be distributed over this sphere, there will be 7.5 X 10^- 4 grammes per cubic centimetre. If the mass of an iron atom be put at 5.6 X 10^-3 grammes, we find that there will fall a iron atom upon every 8 cubic centimetres of the sphere in question.
It seems as if no known facts can prevent us from assuming by hypothesis that the average density of these flying ions and uncharged atoms and molecules might very well be, for instance, 100 times greater than that found above.

This is not that far off the average density of the ISM (a million particles per cubic meter) but only because the mass of the solar system basically condensed from a comparable volume of gas in the first place.

 

[Michael Mozina]

Most of the nonbaryonic matter will pass through the baryonic and nonbaryonic matter.

This is a silly argument IMO. Due to the extreme distances between stars in a given galaxy, any "collision" between galaxies will result in full solar systems passing right through each other virtually undisturbed. Depending on the relative speed of the collision, the likelihood of solar systems in the galaxy even being influenced much by a star in the colliding galaxy is small. Most stars and solar systems will not actually "collide", but pass right through each other. All this lensing data tells me is that you grossly underestimate the amount of mass inside stars and solar systems, and you probably have the ISM about right. In no way does this demonstrate that DM is nonbaryonic. You *ASSUMED* that.