Fermi and dark matter

[ben m]

Yep. "Magnetism" is "ok" by you folks. Anything that combined the *WHOLE EM FIELD* (like the term "electromagnetic fields") is "never discussed". You guys are so predictable.

There is no mechanism for generating nor sustaining electrostatic fields in these systems. There is a mechanism for generating and sustaining magnetic fields; magnetic fields are directly observed.

 

[ben m]

So evidently we have another "natural" source of high energy gamma rays, and we have no need for "dark matter did it" explanations related to very high energy gamma rays.

Please note that Fermi sees Cyg X3 (a pulsar) as it sees many pulsars. It does not mistakenly associate them with dark matter.

Your whole thesis seems to revolve around "the Fermi team is trigger-happy on discovering dark matter", but every link you provide refutes this.

Anyway: does the observed Fermi galactic-center haze have the spatial and spectral properties of pulsar gamma ray emission? No it does not. You can't "explain" a phenomenon that looks like X by pointing out that there other phenomena look like Y.

 

[Reality Check]

Evidently the answer is "everywhere".

http://www.spacedaily.com/reports/Cosmic_Dig_Reveals_Vestiges_Of_Milky_Ways_Building_Blocks_999.html

Happy Thanksgiving.

Evidently the answer is "in Terzan 5" (a globular cluster) according to MM.

FYI MM: Terzan 5 is inside our galaxy. The Milky way has dust clouds in it. That makes it harder to see things in the Milky Way and less easy to estimate the masses of obscured parts of the galaxy.

The Bad Astronomer has a good post on Terzan 5.

It’s just over 19,000 light years away, toward the galactic center. That area is lousy with thick patches of dust, making it very difficult to see anything, like trying to see a forest through a thick fog.

Happy Thanksgiving.

Once you have digested your turkey perhaps you can explain exactly why dark matter cannot be exotic matter.
We already know that dark matter cannot be anything that you have suggested, e.g. rocks.
We already have evidence that it acts differently than normal matter.

 

[Michael Mozina]

There is no mechanism for generating nor sustaining electrostatic fields in these systems.

Ben, the whole universe might have an electromagnetic field who's origins lie beyond our little visible sliver of the visible universe. So what if we don't understand the "mechanism"?

There is a mechanism for generating and sustaining magnetic fields; magnetic fields are directly observed.

The moment charged particles begin to move around it becomes an 'EM" field Ben. Space is not a "sterile' magnetic environment, nor is it "neutral", it's "current carrying" plasma.

For example, our own sun presumably has a strong magnetic field, but it's cause is *ELECTROMAGNETIC* in nature, and it's physical manifestation in the sun's plasma atmosphere is also *ELECTRO*magnetic in nature. You guys keep trying to sterilize an *ELECTRO*magnetic process, and remove the "electro" part so that the dreaded EU theory doesn't grow. It's bizzare behavior IMO, but I've watched it go on now for years.

Anything and everything is "ok" as it relates to explaining gamma rays with mythical particles because mythical particles fit with the party line dogma. Anything with "electro" in it is "out" and "forbidden", lest thou not be published and shunned forever from mainstream publications.

 

[Michael Mozina]

Evidently the answer is "in Terzan 5" (a globular cluster) according to MM.

No, evidently the answers are 'out there' pretty much all around us because our technologies have always been extremely limited, but they keep being improved over time. As a result, we're going to continue to identify more and more ordinary matter over time.

FYI MM: Terzan 5 is inside our galaxy. The Milky way has dust clouds in it. That makes it harder to see things in the Milky Way and less easy to estimate the masses of obscured parts of the galaxy.

Yes, but that did not stop us from 'estimating' it improperly to begin with. That's my whole point. The universe is more dusty than we realize, and it absorbs and blocks more light than we realize. It's not that the mass is found in some exotic form, it's that we are incapable of identifying all normal matter in even our own physical galaxy, let alone distant ones.

The Bad Astronomer has a good post on Terzan 5.

No thanks, I prefer "good" astronomy where you get to speak freely and question authority openly in scientific integrity.

Once you have digested your turkey perhaps you can explain exactly why dark matter cannot be exotic matter.

Because no forms of exotic matter are known to exist. From the standpoint of empirical physics you have one strike against you from the outset. There's no way you can claim that our current technologies enable us to fully identify all objects in space. We have to "estimate" a lot of stuff, based on a slew of questionable "assumptions" that may or may not be accurate. To date I have no evidence that any exotic forms of matter exist. When you find some that fit all your necessary qualifications, let me know. I'll change my tune. Until then I have better things to do that play around with mythical particle formulas.

We already know that dark matter cannot be anything that you have suggested, e.g. rocks.

No you don't know that. I will take up that topic in another week or so. I need another week to finish up what I'm working on at work and then I'll be happy to bust that show of yours. You keep *oversimplifying* (that's your whole trick by the way) every process to make it "fit" some preconceived formulas you've seen, and you've spent little or no time being even the least bit creative about the layouts of matter in space, or the processes that bind them.

We already have evidence that it acts differently than normal matter.

No, you do not. Ordinary "pebbles" in a distant intercluster medium are going to be "dark" to our technologies. As it relates to this specific thread, you have *ZERO* and I mean "no" physical evidence that exotic matter emits anything, let alone gamma rays.

 

[Tubbythin]

Yes, but that did not stop us from 'estimating' it improperly to begin with. That's my whole point. The universe is more dusty than we realize, and it absorbs and blocks more light than we realize. It's not that the mass is found in some exotic form, it's that we are incapable of identifying all normal matter in even our own physical galaxy, let alone distant ones.

Dust cannot possibly be the answer. Dust blocks out light. Thta's precisely why we it can be difficult to study the centre of our own galaxy in the optical. If we were in a halo of dust we wouldn't see other galaxies Not to mention the fact that dust wouldn't form a halo.

Because no forms of exotic matter are known to exist.

Huh??? Exotic matter is, by definition, difficult to observe. But many many exotic forms of matter have certainly been made. Positronium, lithium-11, muonium, J/psi, antihydrogen...

From the standpoint of empirical physics you have one strike against you from the outset. There's no way you can claim that our current technologies enable us to fully identify all objects in space. We have to "estimate" a lot of stuff, based on a slew of questionable "assumptions" that may or may not be accurate.

The fact that we can see other galaxies is not a questionable assumption.

To date I have no evidence that any exotic forms of matter exist.

This is obviously false. See above.

No, you do not. Ordinary "pebbles" in a distant intercluster medium are going to be "dark" to our technologies.

Pebbles that don't emit or absorb in any measured wavelength. That's some pretty exotic pebbles you got there.

 

[Tubbythin]

Ben, the whole universe might have an electromagnetic field who's origins lie beyond our little visible sliver of the visible universe. So what if we don't understand the "mechanism"?

 

[Michael Mozina]

Dust cannot possibly be the answer.

It can be "part of" the answer.

Dust blocks out light. Thta's precisely why we it can be difficult to study the centre of our own galaxy in the optical. If we were in a halo of dust we wouldn't see other galaxies Not to mention the fact that dust wouldn't form a halo.

Yes, and evidently it *does* block out a higher percentage of light than we first realized according to those recent papers. Dust does in fact have a greater influence on our measurements than we first realized. If these distant galaxies are twice as bright as we first realized, don't you figure that is going to have an impact on our "guetimates" about the amount of standard baryonic material in a galaxy?

Huh??? Exotic matter is, by definition, difficult to observe. But many many exotic forms of matter have certainly been made. Positronium, lithium-11, muonium, J/psi, antihydrogen...

These are all based upon standard particle physics theory and most/all of them enjoy empirical support. "Difficult" doesn't necessary seem to apply to hypothetical, non standard SUSY theory. "Darn near impossible" seems to be more applicable to SUSY theory. LHC is probably your only hope, but there's no guarantee that any new particle found by LHC would in any way relate to SUSY theory.

The fact that we can see other galaxies is not a questionable assumption.

How much light we observe and how much is blocked is based upon a "questionable" assumption, one that's been challenged relatively recently. The amount of small stars in a galaxy per large stars has also been based upon questionable assumptions that have also been recently challenged. A lot of what we think we know about distant galaxies are based upon questionable assumptions.

 

[DazzaD]

Yes, and evidently it *does* block out a higher percentage of light than we first realized according to those recent papers. Dust does in fact have a greater influence on our measurements than we first realized. If these distant galaxies are twice as bright as we first realized, don't you figure that is going to have an impact on our "guetimates" about the amount of standard baryonic material in a galaxy?

No.

Because some of those "guestimates" dont rely at all upon how much dust there is or where it is or how much it "blocks" light.

These are all based upon standard particle physics theory and most/all of them enjoy empirical support. "Difficult" doesn't necessary seem to apply to hypothetical, non standard SUSY theory. "Darn near impossible" seems to be more applicable to SUSY theory. LHC is probably your only hope, but there's no guarantee that any new particle found by LHC would in any way relate to SUSY theory.

Can you outline the key differences then between "standard particle physics theory" and "non-standard SUSY theory"?

Or does your definition each and every time amount to "I have seen it, check, that ones ok, I have not seen that personally, no way it can be the case"?

How much light we observe and how much is blocked is based upon a "questionable" assumption, one that's been challenged relatively recently. The amount of small stars in a galaxy per large stars has also been based upon questionable assumptions that have also been recently challenged. A lot of what we think we know about distant galaxies are based upon questionable assumptions.

By definition an assumption is questionable.

I would like to hear how a purely electromagnetic approach does as good a job or better though.

Without referring to how "the standard model is in disarray and is grasping at straws because we have not fleshed everything out", how is it that the amazingly successful standard model can quantitatively and in great detail account for a such a wide variety of phenomena that a purely electromagnetic approach cannot even dare to match at present?

I dont know a single astrophysicist who seriously believes they know exactly how much light is blocked or that all distances to galaxies are set in stone and wont be challenged by some future experiment.

Anyone who has worked in the field understands the complexities of the issues but to take a particular (few) papers and then to contend that the whole subject is falling down around its ears is a bit too much I would argue.

 

[Tubbythin]

It can be "part of" the answer.

No, it can't.

Yes, and evidently it *does* block out a higher percentage of light than we first realized according to those recent papers. Dust does in fact have a greater influence on our measurements than we first realized. If these distant galaxies are twice as bright as we first realized, don't you figure that is going to have an impact on our "guetimates" about the amount of standard baryonic material in a galaxy?

Not much, no. The rotation curves tell us that the distribution of mass does not reflect the distribution of visible mass. No amount of dust is going to change that.

These are all based upon standard particle physics theory

And SUSY is the simplest extension to the standard model that can explain some of the standard model's shortcomings.

and most/all of them enjoy empirical support.

Right. But they didn't before they were made (obviously). And yet they exist. How can it possibly be that things that once lacked empirical support were found to exist?

"Difficult" doesn't necessary seem to apply to hypothetical, non standard SUSY theory.

I'm not talking about non-standard SUSY theory. I'm talking about the MSSM, the simplest implementation of supersymmetry.

"Darn near impossible" seems to be more applicable to SUSY theory.

Why? What do you know that those physicists at CERN don't? I'd be quite surprised that somebody who knows little about particle physics could have strong evidence of the non-existence of supersymmetric particles and yet those who are dedicating their careers to the search for them are completely unaware of it.

LHC is probably your only hope, but there's no guarantee that any new particle found by LHC would in any way relate to SUSY theory.

A fairly meaningless statement.

How much light we observe and how much is blocked is based upon a "questionable" assumption, one that's been challenged relatively recently. The amount of small stars in a galaxy per large stars has also been based upon questionable assumptions that have also been recently challenged. A lot of what we think we know about distant galaxies are based upon questionable assumptions.

All I've seen is some papers suggesting dwarf galaxies may have more mass than some thought. That in now way changes the dark matter picture.

 

[ben m]

Ben, the whole universe might have an electromagnetic field who's origins lie beyond our little visible sliver of the visible universe. So what if we don't understand the "mechanism"?

a) No, EM fields propagate at the speed of light. If it generates a field here, it has to be within the visible universe.

b) That doesn't sound like the field you keep invoking to cause "discharges" on stars and whatnot.

The moment charged particles begin to move around it becomes an 'EM" field Ben. Space is not a "sterile' magnetic environment, nor is it "neutral", it's "current carrying" plasma.

You've tried to hold this argument dozens of times, MM. This thread is not the place to restart it. Do you want to get back to dark matter and Fermi?

 

[ben m]

It can be "part of" the answer.

No it can't. We've been through this a dozen times. There may be unseen baryons (and new CMB/BBN physics) which increase the baryon budget by 10%, 20%, etc., over what is known today. There cannot be unseen baryons which increase the budget by 500%.

Keep this in mind: current baryon budgets, based on star/gas/dust counting, tend to err very low. BBN and CMB constraints tell us that 4% of the Universe is in baryons. Star/gas/dust mass counting, done naively, tends to locate about 2%-3% of this material "easily". A lot of recent work (having nothing to do with dust, and fairly little to do with stars---it's mostly a question of cold gas distributions), which you would probably find in your enthusiastic Google searches for "missing mass", is involved with getting the visible budget balance up *from* 2-3% to the full expected 4%. There no work whatsoever suggesting that newly-discovered baryons are pushing the baryon budget higher, nor suggesting that some of the nonbaryonic dark matter mass is actually baryons.

Keep that in mind next time you Google. Astronomers expect to need to find some more baryons in order to complete accounting for 4% of the Universe---and indeed they are doing so, gradually. Astronomers have completely ruled out, repeatedly, the hypothesis that baryons make up 24% of the Universe.

 

[Reality Check]

No, evidently the answers are 'out there' pretty much all around us because our technologies have always been extremely limited, but they keep being improved over time. As a result, we're going to continue to identify more and more ordinary matter over time.

Since the discovery of dark matter in 1933 astronomy has managed to measure more and more ordinary matter. They passd the point of dark matter being stars a couple decades ago. Stars are 11% of the mass of galactic clusters. The measured energy/mass of the universe is

• 0.4% stars
• 3.6% intracluster meduim
• ~23% dark matter
• ~73% dark energy

Doubling the number or mass of stars does not effect the need for dark matter. You need to show that it is possible for astronomers to be out by a factor of 60 for the number or mass of stars. Yu have failed to even get close.

Because no forms of exotic matter are known to exist.

Wrong: Dark matter acts as if it is exotic matter. Thus exotic matter is "known to exist".

 

[Aitch]

Wrong: Dark matter acts as if it is exotic matter. Thus exotic matter is "known to exist".

The problem is, if I'm interpreting MM correctly, the only way he'll believe in dark matter is if you give him a little glass* jar labeled 'Dark Matter' and containing something really strange.

* a really special sort of glass, obviously.

 

[Reality Check]

The problem is, if I'm interpreting MM correctly, the only way he'll believe in dark matter is if you give him a little glass* jar labeled 'Dark Matter' and containing something really strange.

* a really special sort of glass, obviously.

That is the problem withh MM's personal definiton of empirical - it does not agree with the one that scientists use. As I asked in a previous (of course ignored by MM) post

Originally Posted by Michael Mozina
Got a gram of "dark matter"?

Got a gram of quarks?
Got a gram of the Sun's core?
Got a gram of the degenerate matter in a neutron star?
Got a gram of neutrinos?
Got a super massive black hole in your lab?
Got a gram of antimatter? (Fermilab in 20 years of operation has produced about 2.3 billionth of a gram).
Got a gram of W bosons?
Got a gram of quark-gluon plasma?

I really should have mention that fact "exotic matter" is not the leading candidate for dark matter. The leading candidate is SUSY particles. We know that the Standard Model has flaws, e.g. cannot account for the observed neutrino oscillations (evidence for massive neutrinos). The addition of supersymmetry (SUSY) to the standard model is one way to fix its flaws. SUSY has weakly interacting massive particles that are as "exotic" as any other particle, e.g. electrons.