Fermi and dark matter

[Reality Check]

Baloney! That is physically impossible. Somehow you're going to have to add mass to account for that additional brightness. As TBT notes, even in the most conservative way of "adjusting' the numbers, some adjustment will absolutely be required.

That is why I said "IMO as a (non-astronomer)".
As TBT notes there will be an insignificant (in terms of astronomical measurements) change in the masses of galaxies. The mass due to main sequence stars will go up by 20%.



You know that (Dark Matter Part I: How Much Matter is There?):

1. Gravitational measurements show that 25% to 30% of the universe is mass.
2. The measured mass of stars are only about 0.5% of the mass in the Universe.
3. The measured mass of the intergalactic medium is 3.6% of the mass in the Universe.

Can you understand that 0.4% is about 60 times less than 25%?


Can you understand that even 1% is less than 25%?

 

[DeiRenDopa]

It does have an effect - the intrinsic brightness of many celestial objects may have been underestimated. That is what the paper states.

IMO (as a non-astronomer) I would say that this has *NO* effect whatsoever on our mass estimation of a galaxy.

Baloney! That is physically impossible. Somehow you're going to have to add mass to account for that additional brightness. As TBT notes, even in the most conservative way of "adjusting' the numbers, some adjustment will absolutely be required.

Once again your (complete?) blindness to (unwillingness to consider?) the quantitative aspects makes your posts ridiculous.

If you truly think that either an environment dependent IMF, or a dustier ISM, or both, renders the results of the many different kinds of observations (each of many different objects, obtained using different techniques) wrt CDM wildly wrong (i.e. out by at least six sigma), then put fingers to keyboard, write a paper, and get it published.

To take just one example: the CDM in a rich cluster is in the IGM, which is where most of the ordinary ("baryonic") mass is too. Is an environment-dependent IMF going to change that? No. Is a dustier ISM in all galaxies in the cluster going to change that? No. (BTW, you do realise, don't you, that massive amounts of dust in the IGM of rich clusters would be screamingly obviously).

Back to Fermi.

AFAIK, the planned Fermi CDM annihilation (or similar) searches concern the MW bulge (and, possibly, the tiny CDM-rich dwarf satellite galaxy Segue I).

Will an environment-dependent IMF substantially reduce the estimated mass of CDM in the MW bulge? No (you do know why, don't you?).

Will a dustier than previously thought ISM substantially reduce the estimated mass of CDM in the MW bulge? No (you do know why, don't you?).

So, wrt the test that this thread is - I guess - supposed to be about, neither of the two recent results which you cite makes any significant difference.

Oh, and don't you think it would be wise to hold off pinning your hopes on just two recent papers ... at least until later ones corroborate their results? You see, as si has pointed out several times, there are essentially three kinds of result from this sort of test; namely, incorrect conclusions (bad data, bad analyses, etc), new models using existing theories, and new theories. With solar system objects, and gravity, there are examples of all three: Pluto (deviations in the orbit of Neptune went away, no tenth planet needed), Neptune (apply Newtonian gravitation), and Vulcan (theory of gravity wrong, GR is better).

But the mass estimation of galaxies is only one part of the detection of dark matter. Most of the normal matter in the universe turns out to be intergalactic medium, i.e. plasma.

Ya, and evidently it's "twice as dusty" too.

No, only the ISM is (or may be) ...

Your whole argument is predicated upon an *accurate* "guestimate" of the amount of "normal" matter in a galaxy, and these recent papers demonstrate that our estimates of normal mass in a galaxy has some
"serious" flaws.

As I have shown, for rich clusters, the mass in the constituent galaxies is pretty much irrelevant.

I could repeat this exercise at a larger scale - cosmology - and the result would be the same ... independent of estimates of the mass of galaxies, there are several sets of independent observations - and analyses - which yield consistent results wrt CDM.

 

[DSo]

The *important* difference is that even the very postulation of a neutrinos came about as a direct result of *EMPIRICAL EXPERIMENTS* which directly measured the energy output of the beta decay process.

And what happens to your argument if and when DM particles are observed in experiments here on earth?

 

[Michael Mozina]

I think your (total?) inability to grasp that theories are quantitative means you cannot, and will not, understand this.

I think your inability to grasp the fact that math alone doesn't demonstrate that something exist in nature means you cannot and will not understand this, but......

It doesn't matter one iota how many many formulas you slap on to the term "God matter". It doesn't matter how many times you point at the sky with those math formulas and claim "God matter did it". Nothing but an empirical demonstration of "God matter" is going to demonstrate that God matter exists and has the properties you claim it has.

What Newton did (among other things) was develop a theory which could account for the observed motions of the Sun, Moon and planets - quantitatively.

Until Newton, no one expected that the heavens would follow rules that are the same as things on the Earth did,

Gah! It's the fact that gravity *DOES* show up on Earth that differentiates "gravity theory" from "God matter theory", not the math!

and following the MM approach, positing that masses attract each other, according to an inverse square law, is just as much a hypothetical as DM.

The existence of gravity is not "hypothetical", it's real and I can experience it personally. That math he came up with could be "right", or it could be "wrong" but the fact that gravity isn't shy around the lab, and it occurs here on Earth, means that we have some hope of confirming or falsifying the math related to any gravity theory. Even if that math (or some other math) is demonstrated to be wrong, "gravity" will not cease to exist in nature, nor will "gravity" stop being a part of "physical reality".

Gravity is *QUALIFIED*, not simply *QUANTIFIED*. Newtons understanding of gravity is quite different than GR, and both of them may one day be replaced with a QM theory about gravity for all I know. In no circumstance will the mathematical model of gravity be the thing that makes it 'real' and makes it have a "real effect" on 'real things". Gravity theories will always enjoy *qualitative* support, even if none of the current mathematical models of gravity survive the next 100 years of technological advancement.

Empirical physics works in a lab even if we don't have a mathematical model to describe it yet. Empirical physics doesn't *NEED* lil ol me to understand the math in order to manifest itself in nature. I can feel gravity and experience gravity, and therefore I have no doubt it is "real", that it "exists in nature" and has some effect on nature, even if I put very little faith in the long term viability of the current mathematical models that describe it.

 

[Michael Mozina]

And what happens to your argument if and when DM particles are observed in experiments here on earth?

That would depend on what "properties" they are shown to have. If for instance these hypothetical particles immediately decay into some ordinary form of matter, my criticism is still valid. If they interact with light my criticism is still valid. If they dont' pass through ordinary matter my criticisms are still valid.

Those 'properties' that keep getting slapped onto DM theory are purely ad hoc properties that are designed to "fill the gaps" on a "custom fit' basis. They are all "made to fit' an otherwise dead theory in an effort to claim that current galactic mass estimates are correct. Nothing about SUSY particles is known, not even if they exist. IMO the odds that they exist at all is low, but definitely worth "checking" anyway. I certainly support the LHC experiments that are designed to look for them.

The odds however that something does exist and has all those ad hoc properties is highly unlikely IMO. It's a lot more likely that we simply blew the mass estimates in a big way and we simply don't have clue how to fix it and our technology is still pretty limited.

If and when we find some SUSY particles and if and when they are shown to have all those claimed properties, then it would be appropriate IMO to point at the sky and claim SUSY particles did it. Until then you compounding hypothetical properties on top of hypothetical entities. That is a religion IMO, not 'science".

 

[DeiRenDopa]

Now here is the crux of the story … All of this was done well BEFORE the neutrino was directly observed.

How is this ANY DIFFERENT from the situation now?

The *important* difference is that even the very postulation of a neutrinos came about as a direct result of *EMPIRICAL EXPERIMENTS* which directly measured the energy output of the beta decay process.

Approx two decades earlier the reverse ... the postulation of GR came about as a direct result of ... what? Certainly no "in the lab" experiments!

The other particles in the decay process were directly measured in the experiment and the amount of left over energy could *only* (no other possible option existed) be caused by a new particle, or a failure in a "law" of physics. No other particle we had identified could account for that specific amount of energy.

Fast reverse to a couple of decades prior ...

The success of Newtonian gravitation in finding Neptune was known to all, and some patchy success seemed to be in hand wrt finding Vulcan (to account for the anomalies in Mercury's orbit). Along comes a radical new theory (of gravity), and claims to be able to account for the anomalies in Mercury's orbit. But, to the MM clones of the day, this radical new idea cannot be tested "in the lab". By the MM definition, it is purely hypothetical ... and the 1919 solar eclipse expeditions? What a joke! The existing theory accounted for the results just as well ...

That "unidentified mass" in a distant galaxy could be caused by anything. There was never a "controlled experiment" performed that directly measured the actual normal mass in those galaxies.

Nor will there ever be ... so all astrophysics is non-science?

We simply "estimated" the amount of normal mass in a galaxy based on a whole range of assumptions. That distant missing mass doesn't *REQUIRE* a new form of matter to exist.

Think early years of the 20th century, think GR ... the anomalies in Mercury's orbit, and the solar eclipse observations do not *REQUIRE* a new form of geometry to exist.

No laws of physics "require" that we postulate a new and exotic form of matter. Nothing absolutely necessitates that we postulate an exotic new form of matter. Our mass estimates are simply wrong for all we know because our technologies are still very limited. We can't actually "count" the number of stars in a galaxy we "estimate" them based on lots and lots of lots of questionable assumptions.

Just as one does not require forces, momenta, energy, work, etc, etc, etc ... angels and fairies and demons will do just fine to explain the observed behaviour of the real world (i.e. your description is not one that includes science ...)

Whereas neutrinos were discovered (and first postulated) via empirical physics in the lab, SUSY particles have not.

So between ~1930 and 1957, no observed neutrinos.

Perhaps it will be next year that SUSY particles are observed "in the lab"?

Perhaps it will be within a decade that MW DM particles are observed in underground detectors?

Helium was first postulated via observations of the Sun (it was later found here on Earth); certain meta-stable states of doubly ionised oxygen are postulated via observations of nebulae (and application of quantum mechanics), none has been observed "in the lab".

Whereas neutrinos were *necessary* to keep laws of physics from being violated, SUSY theory is not.

GR was not *necessary* to keep laws of physics from being violated.

Whereas neutrinos have a known source, SUSY particles do not. There's no comparison because we have not and never could perform a "controlled experiment" to weigh the amount of normal matter in a galaxy. That's the key difference.

Just so that I don't misunderstand ... because (Newtonian) gravity can account for the observed motions of the planets (etc) is completely irrelevant - we have not, and never will, be able to perform a "controlled experiment" with planets "in the lab". Did I get it right?

 

[DSo]

That is a religion IMO, not 'science".

So all the people working in this field are practicing religion then? Oh, but wait if their ideas turn out to be validated in the lab then it is science?

Weird logic. What's your point in all of this?

 

[DeiRenDopa]

I think your inability to grasp the fact that math alone doesn't demonstrate that something exist in nature means you cannot and will not understand this, but......

It doesn't matter one iota how many many formulas you slap on to the term "God matter". It doesn't matter how many times you point at the sky with those math formulas and claim "God matter did it". Nothing but an empirical demonstration of "God matter" is going to demonstrate that God matter exists and has the properties you claim it has.

So if you'd been on the relevant "Royal" society of the time, you'd have canned Newton's work?

[...]

Until Newton, no one expected that the heavens would follow rules that are the same as things on the Earth did,

Gah! It's the fact that gravity *DOES* show up on Earth that differentiates "gravity theory" from "God matter theory", not the math!

Um ... did you miss the part about how "gravity" did not mean - then - what it means today?

Did you not grasp that - until Newton - "gravity" was not a physical law, a law of nature, a natural force, ....?

The thing which you insist "*DOES* show up on Earth" is a theoretical explanation for a bunch of observations ... no reason to suppose it has anything to do with mass, rather than, say, the spirits of Earth and Water (and the spirits of Fire and Air are ruled by quite different gods).

Did you also miss the part about dark energy (in the form of Λ) being just as much "gravity" (which shows up here on Earth) as a ball of lead?

and following the MM approach, positing that masses attract each other, according to an inverse square law, is just as much a hypothetical as DM.

The existence of gravity is not "hypothetical", it's real and I can experience it personally.

Not so.

What is real, and what you experience, are the spirits of Earth and Water; "gravity" is a piece of hypothetical fiction, merely some magic math nonsense dreamed up by someone with far too much idle time on their hands.

The planets travel on their courses due to the rules of the heavens, beyond the reach of even the spirits of Fire and Air.

That math he came up with could be "right", or it could be "wrong" but the fact that gravity isn't shy around the lab, and it occurs here on Earth, means that we have some hope of confirming or falsifying the math related to any gravity theory. Even if that math (or some other math) is demonstrated to be wrong, "gravity" will not cease to exist in nature, nor will "gravity" stop being a part of "physical reality".

You have obviously been far too heavily influenced by these natural philosophers ... I tell you again, "gravity" does not exist, it is a fiction, hypothetical ... what makes heavy things fall is their Earth spirits; what makes things rise is their Air (or sometimes Fire) spirits.

Gravity is *QUALIFIED*, not simply *QUANTIFIED*. Newtons understanding of gravity is quite different than GR, and both of them may one day be replaced with a QM theory about gravity for all I know. In no circumstance will the mathematical model of gravity be the thing that makes it 'real' and makes it have a "real effect" on 'real things". Gravity theories will always enjoy *qualitative* support, even if none of the current mathematical models of gravity survive the next 100 years of technological advancement.

Empirical physics works in a lab even if we don't have a mathematical model to describe it yet. Empirical physics doesn't *NEED* lil ol me to understand the math in order to manifest itself in nature. I can feel gravity and experience gravity,

You keep banging on about this hypothetical nonsense!

You CANNOT "feel gravity", you CANNOT "experience gravity"!

What you feel, and experience, is the Earth spirits.

and therefore I have no doubt it is "real", that it "exists in nature" and has some effect on nature, even if I put very little faith in the long term viability of the current mathematical models that describe it.

Perhaps it's time for you to tell us all what "gravity" is?

 

[Michael Mozina]

So if you'd been on the relevant "Royal" society of the time, you'd have canned Newton's work?

No, I would have said: Well Sir Isaac, I can certainly feel "gravity' as you call it so your gravity theory is well "qualified", and I can see that your quantitative work applies very well here on Earth in empirical experiments too. I can't say for sure that the planets and stars work as you claim they do or that your math will stand the test of time, but "bravo".

Um ... did you miss the part about how "gravity" did not mean - then - what it means today?

Did you not grasp that - until Newton - "gravity" was not a physical law, a law of nature, a natural force, ....?

But we all experience it. Did you miss that part about the fact I can "experience" "gravity" here on Earth? Did you notice that a rock in the lab experiences it too? Did you miss that part about how I can "feel" it and "see' it have an effect here on Earth and therefore I have no problem with you mathematically quantifying it, and I can check your work if I want to? It doesn't even matter one iota whether I "percieve" it as a "force" or a "curvature", I do in fact "feel" gravity every single day. It's fully "qualified" in every empirical way. FYI, I'm not really interested in how you personally think other people thought of gravity prior to Newton. That sounds like a useless trip down denial lane. We experience gravity. It's well "qualified" and shows up in real labs on Earth.

"Electrical current" is also highly "qualified". We can see it's direct effect on plasma in lab. You are therefore welcome to point at the sky and claim "electricity did it" if you like. You might be right or wrong, but at least it's a well "qualified" theory. I know from empirical experiments that neutrinos exist so you're welcome to point at the sky and claim neutrinos did it too. Ditto on the right or wrong aspect, but at least I won't cry foul about a lack of qualification.

I can't see any empirical evidence to suggest that SUSY particles exist or have any of the various properties that you suggest. You can't show me a single controlled instance of a bit of dark matter generating one single gamma ray on Earth, but you expect me to believe "dark matter spirits in the sky did it." Notice a key difference related to *qualification*?

 

[Michael Mozina]

So all the people working in this field are practicing religion then?

In the sense that proponents of Lambda-CDM hold beliefs that are predicated upon multiple leaps of faith in 'unseen entities', yes, it's 96% religion in fact.

Oh, but wait if their ideas turn out to be validated in the lab then it is science?

How would that be different from any other 'religion' in your opinion?

Weird logic. What's your point in all of this?

My point of all this is that we know for a fact that FERMI sees our own sun. We know for a fact that suns and planets emit gamma rays in space. We know that every galaxy contains hundreds of billions of such objects. We know that Thomson and Compton scattering happen and that space is "dusty". We know our universe is huge and our technology is still rather primitive. If there really is any valid reason why you expect me to believe 'dark matter did it", I'd like to see some evidence. So far all I see are handwaves and a lot of silly nonsense about how all these properties "could be" found and *one day" your "religion" might become a "science". I think any "believer" in anything could say exactly that same statement, so I really don't see how you figure it's a helpful or useful argument.

My point is that "dark matter" isn't necessary. It's not likely. It's not even empirically supported in a single instance on Earth, not ever. On the other hand "electrical discharges" do release these wavelengths of light and we see them coming from every major body in our solar system. It's hardly surprising then that FERMI sees gamma rays from our galaxy and there is no evidence at all that anything seen in Fermi images has anything at all to do with "dark matter". There's no empirical connection. It's all a giant "act of faith".

 

[DSo]

My point of all this is that we know for a fact that FERMI sees our own sun. We know for a fact that suns and planets emit gamma rays in space. We know that every galaxy contains hundreds of billions of such objects. We know that Thomson and Compton scattering happen and that space is "dusty". We know our universe is huge and our technology is still rather primitive. If there really is any valid reason why you expect me to believe 'dark matter did it", I'd like to see some evidence. So far all I see are handwaves and a lot of silly nonsense about how all these properties "could be" found and *one day" your "religion" might become a "science". I think any "believer" in anything could say exactly that same statement, so I really don't see how you figure it's a helpful or useful argument.

My point is that "dark matter" isn't necessary. It's not likely. It's not even empirically supported in a single instance on Earth, not ever. On the other hand "electrical discharges" do release these wavelengths of light and we see them coming from every major body in our solar system. It's hardly surprising then that FERMI sees gamma rays from our galaxy and there is no evidence at all that anything seen in Fermi images has anything at all to do with "dark matter". There's no empirical connection. It's all a giant "act of faith".

That's not a point. That's a rant. Maybe even a rant against modern science?

What are you trying to accomplish after 100's of posts on this subject?

 

[Michael Mozina]

That's not a point. That's a rant. Maybe even a rant against modern science?

What are you trying to accomplish after 100's of posts on this subject?

I'm trying to convert you all to form of empirical physics called "EU theory".

 

[Michael Mozina]

I mean, Λ is part of a math formula for gravity, I can point to the sky and say 'gravity did it', and show that the mathematical model matches nature's expression of gravity very well.

Now all you have to empirically demonstrate is your claim that gravity does repulsive tricks.

 

[DeiRenDopa]

I'm trying to convert you all to form of empirical physics called "EU theory".

Well, if that's true, then you're doing a sterling job ... of persuading readers that "EU theory" is, at best, pseudo-science (if not actually anti-science) ...

 

[Michael Mozina]

The *important* similarity is that even the very postulation of dark matter came about as a direct result of *EMPIRICAL EXPERIMENTS* which directly measured

Sorry, I missed this earlier. Evidently you don't comprehend the difference between a "controlled experiment' with real control mechanisms, and a "simple observation" where no control mechanism are involved.

[*]The motion of galaxies in galactic clusters.

All that demonstrates is that we blew our mass estimates.

[*]The motion of stars in galaxies.

Ditto

[*]The distribution of matter in galactic clusters.

Ditto.

[*]The distribution of the intergalactic medium in galactic clusters.

Then there are the
[*]*EMPIRICAL EXPERIMENTS* that may have indirectly measured dark matter here on Earth.

Such as? If you're referring to neutrinos, neutrinos already have a proper scientific name.

*EMPIRICAL EXPERIMENTS* that are being done now to directly measured dark matter here on Earth.
[/LIST]

That seems to be your one and only rational response IMO. Of course even here you evidently "assume" or "have faith" in the idea that not only will they find such a thing, it will also just happen to have all those specific properties you need it to have. That's quite a leap of faith.

 

[DeiRenDopa]

No, I would have said: Well Sir Isaac, I can certainly feel "gravity' as you call it so your gravity theory is well "qualified", and I can see that your quantitative work applies very well here on Earth in empirical experiments too.

(bold added)

Such as? The ones on "gravity", I mean ...

BTW, are you sure Newton - or any of his contemporaries - would know what you're talking about ("I can certainly feel "gravity' as you call it")?

I can't say for sure that the planets and stars work as you claim they do or that your math will stand the test of time, but "bravo".

Um ... did you miss the part about how "gravity" did not mean - then - what it means today?

Did you not grasp that - until Newton - "gravity" was not a physical law, a law of nature, a natural force, ....?

But we all experience it.

No we don't.

How many times to I have to tell you!

When you fall, it's the Earth spirits.

When you rise, when submerged in water, it's the Water spirits.

When hot air rises, it's the Air spirits, infused with Fire spirits.

And so on ...

What you "experience" is falling, or rising (when submerged in water), or floating (when on water). The feelings are quite different, and distinct.

Further, your experience is a poor guide ... how do you think flight simulators (to take just one example) give you the fully authentic feeling of falling? of accelerating upwards ('against gravity')?

Did you miss that part about the fact I can "experience" "gravity" here on Earth? Did you notice that a rock in the lab experiences it too?

If said rock is floating in mercury, it is not experiencing gravity.

The leaves in my back yard, on a windy day, do not experience gravity.

The fish in my neighbour's aquarium do not experience gravity.

And so on.

"Gravity" is hypothetical, something made up by natural philosophers ...

Did you miss that part about how I can "feel" it and "see' it have an effect here on Earth and therefore I have no problem with you mathematically quantifying it, and I can check your work if I want to? It doesn't even matter one iota whether I "percieve" it as a "force" or a "curvature", I do in fact "feel" gravity every single day. It's fully "qualified" in every empirical way. FYI, I'm not really interested in how you personally think other people thought of gravity prior to Newton. That sounds like a useless trip down denial lane.

Actually, it's an interesting example of how easily we fully internalise the results of centuries of physics, and how hard it is to recognise that things like "gravity" are not what we experience, or feel ...

We experience gravity. It's well "qualified" and shows up in real labs on Earth.

"Electrical current" is also highly "qualified". We can see it's direct effect on plasma in lab.

Same deal, ditto wrt interactions mediated by gluons and the W's and the Z, ...

You are therefore welcome to point at the sky and claim "electricity did it" if you like. You might be right or wrong, but at least it's a well "qualified" theory. I know from empirical experiments that neutrinos exist

But you didn't, certainly not before 1930 ... and you may know that SUSY particles exist too, perhaps as early as 2011 ...

so you're welcome to point at the sky and claim neutrinos did it too. Ditto on the right or wrong aspect, but at least I won't cry foul about a lack of qualification.

That's great news!

So there will be no more screeds denouncing the Λ version of dark energy, nor any cosmological models which incorporate it? After all, Λ is merely one part of a mathematical equation which describes gravity, and can be shown to exist, by pointing to things in the sky ...

I can't see any empirical evidence to suggest that SUSY particles exist or have any of the various properties that you suggest.

But the day they turn up in LHC experimental results you will, right?

And the day XENON (or another DM detector) records DM particle footprints you will, right?

You can't show me a single controlled instance of a bit of dark matter generating one single gamma ray on Earth, but you expect me to believe "dark matter spirits in the sky did it." Notice a key difference related to *qualification*?

No I can't, and don't, see that ... "gravity" is purely hypothetical, as is "electric current". All you are doing is cherry picking from the centuries of physics that which you wish to call "*qualification*"; this is not objective, is not independently verifiable, and is internally inconsistent.

IOW, the very antithesis of science.

 

[Michael Mozina]

Well, if that's true, then you're doing a sterling job ... of persuading readers that "EU theory" is, at best, pseudo-science (if not actually anti-science) ...

Ya right, talk about political spin doctoring.

Electrical discharges show up in a lab DRD, so unlike your beloved dead inflation deity, your dark evil energy theories and your dark matter invisible stuff, EU theory cannot ever be a form of pseudo-science. How could *ANYTHING* be worse that 96% metaphysics?

In any given application, EU theory could be right or it could be wrong, but electricity definitely shows up in a lab and in nature. You might whine about quantification, or lack thereof, but you can't even dispute the fact that electrical discharges emit gamma rays in nature, right here on Earth and many places inside this solar system. As it relates to what we observe in Fermi images, electrical discharge theory will always be a "better" scientific theory than "dark matter did it".

 

[Tubbythin]

So, just out of curiosity, why did you subjectively decide to assume that there were the same number of point sources (just larger) rather than simply doubling the number of point sources?

I didn't. You said:

If it's "twice as bright" as we realized, why wouldn't that equate to a doubling of the number of stars and solar systems in a galaxy?

I was giving some indication of why.
Have your factor of 2 for all I care. You've successfully shown that even if we have made such a mistake, DM is still an absolute necessity.

 

[Michael Mozina]

But you didn't, certainly not before 1930 ... and you may know that SUSY particles exist too, perhaps as early as 2011 ...

But the day they turn up in LHC experimental results you will, right?

Most of that last post isn't worth responding to, but this comment warrants a response. Unlike the dead inflation deity, 'dark matter' does have one redeeming quality. It's existence or lack thereof can be' put to a real empirical test. What's going to happen if 2013,14,15 roll around and there's no confirmation of a SUSY particle? What then? Will you 'give up your faith"? Will you accept that "electrical discharges" might be the real culprit of some distant gamma rays?

When you can show me some something more than some math formula, and you have some empirical physics to compare it with, let me know. Let me know if it has all those nifty properties you keep assigning to it, like longevity and gamma ray vision and the ability to pass through walls in a single bound. Until that time your beliefs are based upon blind faith in 'unseen things'.

 

[Tubbythin]

Please read my response to Dso. It's not just a question of "could we empirically demonstrate it" at the moment they were proposed, it's the fact that no laws of physics are at stake without a SUSY particle, and no empirical experiment requires that a SUSY particle exist.

Very well:

The *important* difference is that even the very postulation of a neutrinos came about as a direct result of *EMPIRICAL EXPERIMENTS* which directly measured the energy output of the beta decay process.

This isn't a difference. The requirement of DM comes from "*EMPIRICAL EXPERIMENTS*" that measure the mass in visible matter, the distribution of mass in visible matter, the mass in invisible matter and the distribution of mass in invisible matter.

The other particles in the decay process were directly measured in the experiment and the amount of left over energy could *only* (no other possible option existed) be caused by a new particle, or a failure in a "law" of physics.

No other particle we had identified could account for that specific amount of energy.

No known SM particles or MACHO objects can account for the galactic rotation curves and cluster rotation curves.

That "unidentified mass" in a distant galaxy could be caused by anything.

This is of course so blatantly false I won't bother to say anymore.

There was never a "controlled experiment" performed that directly measured the actual normal mass in those galaxies.

There have been plenty.

We simply "estimated" the amount of normal mass in a galaxy based on a whole range of assumptions.

Independent measurements give the same results. Even the error bars imposed by any simplifying assumptions cannot possibly account for the roation curves. Remember, these rotation curves don't only tell us how mcuh but in what distribution the DM is found.

That distant missing mass doesn't *REQUIRE* a new form of matter to exist.

Yes, it does.

No laws of physics "require" that we postulate a new and exotic form of matter.

Sure we do. If we want to keep our law of gravity that is absolutely what we must do. There is simply no other alternative that is consistent with the observational facts.

Nothing absolutely necessitates that we postulate an exotic new form of matter.

Well no. We could change out law of gravity. But you don't want to do that either.

Our mass estimates are simply wrong for all we know because our technologies are still very limited. We can't actually "count" the number of stars in a galaxy we "estimate" them based on lots and lots of lots of questionable assumptions.

Then how come different, independent mass estimates agree? How come the different mass distribution measurements agree? The discrepancy between the visible matter and the galactic roation curves isn't even particularly difficult to see. It can probably be done in an undergrad lab.

Whereas neutrinos were discovered (and first postulated) via empirical physics in the lab, SUSY particles have not.

The Universe is our lab Michael. Unless you want to reject the whole of astronomy.

Whereas neutrinos were *necessary* to keep laws of physics from being violated, SUSY theory is not.

Not specifically SUSY, no. But some kind of non-SM particle.

Whereas neutrinos have a known source, SUSY particles do not.

Sure they do. They'd be residues of the Big Bang. Just like most of the helium we have in the Universe. Now, remind us. How was helium discovered?

There's no comparison because we have not and never could perform a "controlled experiment" to weigh the amount of normal matter in a galaxy. That's the key difference.

Sure we can. Its been done.You just have no idea what "controlled experiment" means.

What specific "control" mechanism are you referring to?

Take your pick. Say... measuring the radial profile of HI in a spiral galaxy. Please explain to everyone how this is not a controlled experiment.

By the way, don't think I haven't noticed that you completely ignored my corrections to your wild assertions about physicists making wild assertions

Let's recap:

Correction: One of the things you *NEED* from you ad hoc gap filler is longevity because without it, your theory is toast. You therefore "made up" a "necessary property" for your mythical gap filler, in this case longevity.

Completely wrong. The properties of SUSY particles come QM, not from DM.

It was a property you created based on *NEED* not upon "observation" in a lab.

Nope. Completely wrong. The properties of SUSY particles come QM, not from DM.

Even if we do ever find a SUSY particle in a collider experiment, how do you know it's going to last even a full millisecond before reverting into something we already know about? Pure faith? Ad hoc need? What?

Nope. Completely wrong. Many (most?) SUSY theories have a lightest stable particle. This is a conclusion drawn from QM plus the SM, not from DM observations.

Now, are you going to retract your wild, ignorant, stupid and completely wrong allegations?