Fermi and dark matter

[Reality Check]

You forgot the whole "cause/effect" benefit of "controlled experiments".
...snip...
You can't do that with pure observation, you can't necessarily isolate a "cause".

Actually there is no guarantee that you can isolate a "cause" from controlled experiments either. Some experiments are impossible or too expensive to do. For example what is the 'cause' of cosmic rays and what controlled experiment do you propose to establish it?

Here is a "pure observation": Light from stars have absorption lines in them. Can you isolate a 'cause' for these absorption lines?

It's evidence of "missing mass" or 'unidentified mass'.
...snip...

Just measuring the the mass distribution is evidence of "missing mass". The evidence that the mass is not normal matter is: the three observations of dark matter separated from normal matter: Bullet Cluster,MACS J0025.4-1222 and Abell 520.

Yes there is. The leap of faith is similar to the UFO scenario. You are assuming that because we cannot identify the object, it must *NECESSARILY* be from another planet. In my analogy, yes, it's currently "unidentified", but it could be (and probably is) from *THIS* planet. You're making a huge assumption to claim that the missing mass is anything other than ordinary matter.
[/qote]
No there is not.

Ah, here's where the ridicule begins? What up with that? If you can't beat me via empirical physics, try a personal attack? You must be getting desperate.

It is not a personal attack. Any intelligent person can see that the three observations (empirical physics!) of dark matter separated from normal matter (Bullet Cluster,MACS J0025.4-1222 and Abell 520) are overwhelming evidence for dark matter.

Sure but you refused to consider that fact that the missing mass could be ordinary matter. You refused to actually "confirm" any of the properties of your metaphysical brand of "dark matter". You simply "assumed" all of them on an "as needed" basis to fill the gaps of your otherwise failed mass calculation theory. Even when there is evidence presented to you that we may have underestimated the number of stars in galaxies by a large factor, you still *assume* that new and exotic matter is necessary or required. Why?

Because:
Gravitational measurements show that 25% to 30% of the universe is mass.

1. The measured mass of stars are only about 0.5% of the mass in the Universe.
2. The measured mass of the intergalactic medium is 3.6% of the mass in the Universe.

I can understand that 0.4% is about 60 times less than 25%?
I can understand that even if astronomers are out by a factor of 2 then 1% is less than 25%?
I can understand that even if astronomers are out by a factor of 10 then 4% is less than 25%?
I can understand that even if astronomers are out by a factor of 50 then 20% is less than 25%?

Can you?

 

[Michael Mozina]

Fair point.

I don't think Michael's seen it though, and arguably a second hand experiment relayed by verbal means is less reliable than one relayed by photons directly from the experiment, which is what an astronomical observation is.

I really don't grasp why you (lots of astronomers) call these simple observations "experiments". There is no control mechanism in an "observation" and therefore there is no way to determine "cause" in these types of "observations". We observe gamma rays. Period. We aren't controlling them. We aren't controlling the voltages, the amps, the number of "dark matter" particles, or anything of the sort. We therefore have no clue as to "cause" of the gamma rays.

The empirical difference between our positions is that I can physically demonstrate a "cause/effect" relationship between "discharges" and gamma rays. Even still I can't "experiment" with the idea in space. I can "look for evidence" but since I have no control of distant events, and limited technology, there's no cause/effect determination that is possible from this simple "observation" of gamma rays.

 

[DeiRenDopa]

Now we're into repeat mode ...

EITHER you trash GR, because it cannot be demonstrated "in the lab", and insist that astronomers try harder to find Vulcan.

OR you accept that GR is a better theory of gravity (than Newton's) BECAUSE it can do the numbers on the sky, DESPITE the fact that no one can demonstrate it "in the lab"*

Bzzt. False dichotomy fallacy. Minus 5 points for you. Is it true that we use Einstein's theories in GPS systems? I've heard that statement before but I've never actually checked it out.

Dude, the point of this exercise is to see - using historical examples - if your approach works.

GPS etc came many decades after Pound/Rebka, and neither of these - nor any other test of GR - involves creating planets orbiting the Sun "in the lab", in order to observe the perihelia.

Imagine an MM clone writing in the 1920s, 1930s, 1940s, - you get the idea - Pound/Rebka, GPS, artificial satellites, space probes, the HST, etc, etc, etc are all in the far future (if imaginable, credibly, at all).

During this period the MM clone would have written just as you have done, concerning "gravity", controlled experiments "in the lab", a perfectly good alternative explanation that astronomers were not spending time on (Vulcan)*, etc, etc, etc.

I accept "GR theory" (the way Einstein taught it) with the constant of gravity set to zero. I'm not into your blunder theory variation that is stuffed with magic because I've never seen gravity do repulsive tricks.

You don't get to pick and choose ... unless you admit, openly and honestly, that you are being non-scientific (i.e. subjective, idiosyncratic, and inconsistent); gravity with Λ does just as good a job of accounting for 'numbers in the sky' as GR did for the orbit of Mercury.

Ready to make the big admission, MM? That all your posturing amounts to non-science, pure and simple?

* well, that would have been the ignorant claim; the reality, of course, may have been quite different ...

 

[Michael Mozina]

Actually there is no guarantee that you can isolate a "cause" from controlled experiments either.

I suppose it depends on the experiment but what's the point of having a control mechanism if you aren't trying to isolate cause?

Some experiments are impossible or too expensive to do. For example what is the 'cause' of cosmic rays and what controlled experiment do you propose to establish it?

Well, EM fields have been known to accelerate charged particles to very high speeds, so I'd guess the EM field is responsible for many of them.

Here is a "pure observation": Light from stars have absorption lines in them. Can you isolate a 'cause' for these absorption lines?

Not from the observation itself, but I might be able to do that in controlled experiments here on Earth.

Just measuring the the mass distribution is evidence of "missing mass".

It still tells you *nothing* about it's composition.

The evidence that the mass is not normal matter is: the three observations of dark matter separated from normal matter:

That is not 'evidence that the mass is not normal matter". All that is is 'evidence" that most of your 'missing mass" in likely to be contained inside of solar systems. That's hardly "big news" to a guy that believes in heavy element suns.

We're now going around in circles because you refuse to acknowledge that all this lensing data tells us is where this 'missing mass' is located and maybe a little bit about it's composition. If most of that "missing mass" is in the form of "clumps" (suns, planets, moons, comets, asteroids, etc) the matter is not likely to interact with "clumps" in the colliding galaxy. Evidently most of our 'missing mass' follows the infrastructure of the solar systems, not the ISM. That's all your colored diagrams show us. Everything else you said is "imagined". You "imagine" these color represent something they do not. They do not tell us which of the matter is contained in ordinary elements from the periodic table and which are not. They only tell us where our mass estimates are most flawed, and evidently it's not the ISM where we're really off the mark. Like I said, that is hardly news to me personally.

 

[Michael Mozina]

You don't get to pick and choose ... unless you admit, openly and honestly, that you are being non-scientific (i.e. subjective, idiosyncratic, and inconsistent);

Well, choosing to trust empirical physics is in fact a "subjective" choice I suppose. It is however completely consistent and it is entirely "scientific". I do get to "pick and choose" to have beliefs, or lack of belief based on whether or not an idea can be empirically demonstrated. There's nothing "non-scientific" about empirical physics.

gravity with Λ does just as good a job of accounting for 'numbers in the sky' as GR did for the orbit of Mercury.

Ya, and "gravity" shows up in a lab too DRD. Gravity however does not do any of repulsive tricks in empirical tests.

Ready to make the big admission, MM?

Sure. Care to now make the big admission that you cannot demonstrate that the term "dark matter" is anything other than ordinary matter you can't identify yet? Care to make the big admissions that exotic forms of "dark matter" cannot be shown to emit anything under any circumstance because it's never happened in the whole history of Earth as far as you know?

That all your posturing amounts to non-science, pure and simple?

Your dead inflation deities and dark stuff amounts to non-scientific religion, pure and simple. Like a YEC, you "hope" (and evidently pray) that your beliefs will "one day" be vindicated via empirical physics, even though today you are completely without empirical support of your beliefs. Like YEC only Lambda-CDM and YEC require "faster than light expansion". Pure coincidence?

 

[DeiRenDopa]

Dude, your gross ignorance is showing.

There is ~seven decades of effort, strenuous effort, spent on exactly this.

Only after all such avenues had been investigated, and came up empty, did CDM really come into its own.

How about those two revelations I mentioned? Ooops?

I look forward to your reading your paper on this; until then ...

IIRC, one of the first sets of HST observations was aimed at determining if there were sufficient red dwarfs in the halo to account for the known missing mass ... there weren't (and MACHO, OGLE, etc, etc, etc subsequently, and independently, verified this result).

So ultimately a lot of the missing mass turns out to be related to "dust" and the "assumption' related to how many small stars to small stars we can expect to observe.

Repeating your misunderstandings doesn't magically turn them into physics, MM.

I guess you really don't comprehend the difference between "empirical physics' and stuff someone just makes up in their head.

I understand that the MM approach is subjective, idiosyncratic, and inconsistent ... i.e. that it is not science.

Let's do a test: should you cease posting - here or anywhere on the internet - for an extended period, can you honestly say that anyone (a particular person, or persons) could carry on making the case you are making? If not, then haven't we just demonstrated that your approach is, in fact, subjective, and idiosyncratic?

I guess you have it in your head that our mass estimates for galaxies is "correct", but I just provided you with two papers to demonstrate that this is a false assumption and our mass estimate numbers could be off by several multiples.

Repeating your misunderstandings doesn't magically turn them into physics, MM.

 

[DeiRenDopa]

Ooops. [...]

IMO there's still a "cause/effect" issue going on that has absolutely nothing whatsoever to do with "dark energy". Why? Because "dark energy" doesn't do anything to plasma in a lab whereas the EM field does.

But, as we have seen - over and over and over again - your "O" is subjective, idiosyncratic, and inconsistent.

Got a paper or three in the works, MM? Where you show - using numbers etc - that the EM field (and plasma) will do the trick? If not, why not?

 

[DeiRenDopa]

Well, choosing to trust empirical physics is in fact a "subjective" choice I suppose. It is however completely consistent and it is entirely "scientific". I do get to "pick and choose" to have beliefs, or lack of belief based on whether or not an idea can be empirically demonstrated. There's nothing "non-scientific" about empirical physics.

[...]

So, is the prominent 500.7 nm emission line, seen in many nebulae, due to nebulium, or [OIII]?

Do neutron stars exist?

Is SgrA* an SMBH?

And so on.

Can you explain, again, please how this works? Specifically, what are the objective, verifiable, consistent rules regarding extrapolation beyond "in the lab" environments?

 

[Reality Check]

If you want to continue this discussion then it should be in the previous thread where you stated this "missing matter" stuff.
Maybe you can answer the simple question about colliding blobs that you have been avoidig since 18 July 2009 (108 days and counting).

Alternately I could post the question here but I thnk that counts as cross-posting.

It still tells you *nothing* about it's composition.

It tells you that is is not normal matter.
It tells you that you have to do experiments and observe more to find out what the composition of dark matter actually is.

That is not 'evidence that the mass is not normal matter". All that is is 'evidence" that most of your 'missing mass" in likely to be contained inside of solar systems. That's hardly "big news" to a guy that believes in heavy element suns.

You have just claimed that stars are 60 times more massive than astronomers have measured.
That is about the silliest thing that you have said. I hope that you are joking.

You are still ignorant of the fact that measurement show most of the visible matter in the universe is not in stars (0.4%). It is in the intergalactic medium (3.6%).

You are still ignorant about the fact that the three observations of dark matter separated from normal matter (Bullet Cluster,MACS J0025.4-1222 and Abell 520) are about the intergalactic medium (most of the mass in the galactic clusters).

We're now going around in circles because you refuse to acknowledge that all this lensing data tells us is where this 'missing mass' is located and maybe a little bit about it's composition.

The lensing data for non-colliding galactic clusters tells us that there is 'missing matter" located mostly between galaxies. It tells us little (or nothing) about its composition.

But the lensing data for the Bullet Cluster,MACS J0025.4-1222 and (maybe) Abell 520 tells us that most of the intergalactic medium (and so most of the mass) in those clusters acts differently from normal matter.
This non-normal matter acts as if it interacts weakly with other matter (possibly only electromagnetically). It passes through the normal matter and forms blobs to each side in the observations.
(see this post for the simple question that you hv

If most of that "missing mass" is in the form of "clumps" (suns, planets, moons, comets, asteroids, etc) the matter is not likely to interact with "clumps" in the colliding galaxy.

Still displaying your ignorance:
intergalactic medium not stars,
Colliding galactic clusters not galaxies.

Evidently most of our 'missing mass' follows the infrastructure of the solar systems, not the ISM. That's all your colored diagrams show us.

And yet more ignorance.

Have a look at The Camera that Changed the Universe: Part 4

What can you learn from this? Well, other than all sorts of things about the lensed galaxies, you can learn about dark matter! You see, gravitational lensing only cares about mass, and so we can figure out where -- in a cluster like this -- the mass is distributed. The results are breathtaking.

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.

Emphasis added for those who cannot understand that the diagram shows massive amounts of mass outside of galaxies.

If I remember rightly, the density of the inergalactic medium in this surface density diagran is about 0.1 gm/square cm.

 

[Michael Mozina]

Maybe you can answer the simple question about colliding blobs that you have been avoidig since 18 July 2009 (108 days and counting).

You're a trip. I have not 'avoided' you on this issue at all, in fact I've been in your collective face about it for years. In all that time not one astronomer has been able to round up even a single gram of this magic matter stuff, and yet you expect me to believe you anyway.

It tells you that is is not normal matter.

It tells you *nothing of the sort*! You simply *assumed* that it is not "normal matter". All you know is that our technologies are limited and you can't "see" all the matter in a galaxy. Big deal. Nothing unusual there.

It tells you that you have to do experiments and observe more to find out what the composition of dark matter actually is.

Well, I 'sort of' agree with you, at least in the sense that it is still relevant and necessary to explain the "missing mass'. Again however there is zero empirical evidence that any of that missing mass is anything other than 'normal matter'.

You have just claimed that stars are 60 times more massive than astronomers have measured.

Actually no, I said they were more abundant than you realize and most of your "missing mass" tracks with the solar system infrastructure according to the lensing data.

I'm going to skip some of the redundant stuff.

This non-normal matter acts as if it interacts weakly with other matter (possibly only electromagnetically).

Well duh! If two solar systems pass by one another at a couple millions of miles per hour at a couple light years distance, they aren't likely to interact with each other "strongly". In fact they may hardly interact at all. Again, let me state emphatically that you know absolutely nothing at all about the composition of that unknown material based on this information..

It passes through the normal matter and forms blobs to each side in the observations.

With enough velocity and momentum, normal matter "passes through" normal matter too. So what? Solar systems are typically separated by light years. In in a high speed galaxy "collision" it's highly unlikely that the solar system infrastructures will directly collide. Even if a few stars or planets actually do actually slam into one another, the vast majority of objects in the solar systems will not collide but pass right through to the other side. In no way is that behavior "mystical" or "magical" or even "unexpected". So what? Ordinary matter would be expected to "pass through" any sort of 'collision' process in "vast quantities", whereas particles in the ISM might actually "collide".

That is entirely consistent with the core stellar infrastructure passing right through the other galaxy. Based on the distances between stars, that is hardly surprising. A "direct hit" between two stars is an astronomically low probability.

We're going around in circles now because you absolutely refuse to acknowledge that the reason we cannot 'see' this material is due to the limits of our technology. The reason we can't tell what it's made of is due to the limits of our technology. You can't tell what type of matter is 'missing', and you certainly cannot tell what it's made of from millions if not billions of light years away. You are simply "assuming" that this is some sort of exotic material. That is a pure act of faith on your part. You don't know that. You *assumed* that. You don't know that our galaxy mass estimates are anywhere near accurate so you really have no idea how much normal material is present, let alone be sure if you need anything other than normal material.

I showed you evidence that the universe is much brighter than we expected and galaxies are likely to have far more smaller stars per large star than we used to believe. The net result is that we may easily be able to double or triple the amount of normal matter in a given galaxy (like your collision galaxies), demonstrating that a lot of that 'dark matter' is composed "normal matter" despite your wild claims to the contrary.

An unidentified flying objects isn't *NECESSARILY* from another planet. Likewise "missing mass" isn't "SUSY material" (with all the ad hoc properties you assigned to it all willy nilly).

 

[Michael Mozina]

What exactly were you expecting to "see" anyway?

Considering the distances involved with solar systems, they will most likely pass through one another. Likewise, even the distance between particles in the ISM could be substantial and not even individual atoms/ions in the ISM would necessarily "collide". Even much of the the material in the ISM could 'pass through' ordinary matter. I fail to understand exactly what it is about this image that you find surprising in terms of what to expect from normal matter (like that dust and doubling of point sources).

 

[DeiRenDopa]

[...]

It tells you that is is not normal matter.

It tells you *nothing of the sort*! You simply *assumed* that it is not "normal matter". All you know is that our technologies are limited and you can't "see" all the matter in a galaxy. Big deal. Nothing unusual there.

Are you sure?

Can you describe a distribution of normal matter, in a rich cluster of galaxies, which is consistent with all relevant astronomical observations?

An order of magnitude "consistent with" will do (for now).

If you can't, what objective, independently verifiable basis is there for your claim?

It tells you that you have to do experiments and observe more to find out what the composition of dark matter actually is.

Well, I 'sort of' agree with you, at least in the sense that it is still relevant and necessary to explain the "missing mass'. Again however there is zero empirical evidence that any of that missing mass is anything other than 'normal matter'.

Only in the sense that astronomical observations do not constitute "empirical evidence".

If you discount such observations, why do you bother writing posts about astronomy?

[...]

It passes through the normal matter and forms blobs to each side in the observations.

With enough velocity and momentum, normal matter "passes through" normal matter too. So what? Solar systems are typically separated by light years. In in a high speed galaxy "collision" it's highly unlikely that the solar system infrastructures will directly collide. Even if a few stars or planets actually do actually slam into one another, the vast majority of objects in the solar systems will not collide but pass right through to the other side. In no way is that behavior "mystical" or "magical" or even "unexpected". So what? Ordinary matter would be expected to "pass through" any sort of 'collision' process in "vast quantities", whereas particles in the ISM might actually "collide".

That is entirely consistent with the core stellar infrastructure passing right through the other galaxy. Based on the distances between stars, that is hardly surprising. A "direct hit" between two stars is an astronomically low probability.

What happened to all the light from the stars which are the primaries of all the solar systems?

Where did all the mass which stars that have passed through the red giant-PNe stage of evolution shed go?

And so on.

We're going around in circles now because you absolutely refuse to acknowledge that the reason we cannot 'see' this material is due to the limits of our technology. The reason we can't tell what it's made of is due to the limits of our technology.

Actually, the main reason why we keep going on this merry-go-round is that you absolutely refuse to acknowledge that astronomers have many independent techniques for estimating the distribution and composition of ordinary (normal) matter in the IGM of rich clusters.

Where does this willful ignorance come from?

You can't tell what type of matter is 'missing', and you certainly cannot tell what it's made of from millions if not billions of light years away.

Of course he can ... you just don't want to listen.

You are simply "assuming" that this is some sort of exotic material. That is a pure act of faith on your part. You don't know that. You *assumed* that. You don't know that our galaxy mass estimates are anywhere near accurate

Of course he does ... you just don't want to listen.

so you really have no idea how much normal material is present, let alone be sure if you need anything other than normal material.

I showed you evidence that the universe is much brighter than we expected and galaxies are likely have far more smaller stars per large star than we used to believe.

You did not.

You cited two PRs, and when confronted with copies of the papers*, refused to read them.

Further, you have refused to show - you know, with numbers and equations - how the findings reported in those papers affect determination of the distribution of mass within a normal spiral galaxy (HINT: the need for a DM halo is just as strong with or without these papers' results).

You have also refused to cite papers - of which there are dozens, possibly hundreds - which report findings different from (at odds with) these two.

And so on.

IOW, the case you continue to present continues to be subjective, deliberately misleading, and inconsistent.

The net result is that we may easily be able to double or triple the amount of normal matter in a given galaxy (like your collision galaxies), demonstrating that a lot of that 'dark matter' is composed "normal matter" despite your wild claims to the contrary. [...]

(bold added)

"We" are waiting for you to do exactly that.

How's the paper coming along, MM?

* preprints actually

 

[Michael Mozina]

Are you sure?

Positive. You and I don't have the technology necessary to see 'everything' in a galaxy. We subjectively 'interpret' a whole lot based on a limited set of data.

Can you describe a distribution of normal matter, in a rich cluster of galaxies, which is consistent with all relevant astronomical observations?

Nope, and neither can you which is why you're stuffing the gaps with "dark matter".

If you can't, what objective, independently verifiable basis is there for your claim?

My claim of what? All I know is we have relatively primitive technology that limits our capabilities. We can't account for all the mass in a galaxy based on our current mass estimates. So what? None of these facts necessitates new and exotic "made up" matter with ad hoc properties galore. I'd say it's time to "scrap" the mass estimation techniques and start over again.

If you discount such observations, why do you bother writing posts about astronomy?

You're putting a very odd 'spin' on statements (again). I don't discount the observations of "missing mass". I "discount" your belief that you already know/knew exactly how much "normal" matter exists in any given galaxy in any of those lensing studies. All you can do here is use "flawed" mass estimation techniques, and then compare it to the lensing data "measurements", and thereby "test" your mass estimation techniques. They *FAILED MISERABLY*. Let that mass estimation technique die a natural death and try again.

If you *insist* on sticking with your old and "failed" theories of "normal mass" estimation, and want to call the difference "dark matter", ok. Don't however turn around and pretend your failed mass estimation techniques were valid all along and the difference is made up of "exotic matter" with ad hoc properties galore.

 

[Michael Mozina]

Because:
Gravitational measurements show that 25% to 30% of the universe is mass.

What pray tell is the rest made of? Please resist the need to stuff the gaps of your ignorance with useless terms like magic energy.

[*]The measured mass of stars are only about 0.5% of the mass in the Universe.

You didn't "measure" the mass of the stars, you "estimated" the mass of the stars. Those estimate were based upon a whole host of assumptions like the amount of light absorbed by dust, etc, all of which have now been shown to be "questionable" at best.

[*]The measured mass of the intergalactic medium is 3.6% of the mass in the Universe.

Again, this too is 'assumed' and/or "estimated", it is not "measured".

I can understand that 0.4% is about 60 times less than 25%?

I can understand that when a mass estimation technique is that far off, it's time to give it a proper scientific burial and call it "falsified" once and for all. Evidently we need some new mass estimation techniques that jive with the lensing data?

All the rest of your "assumption" are evidently based on the false belief that we have accurately "measured" the amount of mass in a galaxy, when in fact we never did. We "estimated' that mass, and clearly we did a pitiful job that in no way agrees with the lensing data. One of the two "techniques" for "measuring" the mass of a galaxy is wrong, and one is correct. The lensing data is most likely to be "correct". The "estimation' process is most likely to be incorrect because it is based on far many more assumptions than the lensing data.

All this information tells us ultimately is that the mass estimation techniques we use today are nearly useless at determining that actual amount of mass in a galaxy. Period.

It does *not* tells us that *BOTH* methods of determining mass are correct as you are trying to claim! That is simply an "outrageous" claim IMO.

 

[Michael Mozina]

They only tell us where our mass estimates are most flawed, and evidently it's not the ISM where we're really off the mark. Like I said, that is hardly news to me personally.

The more I think about it, the more I think this statement is less than accurate. I really don't know how much of the ISM is likely to simply 'pass through' the ISM of the other galaxy. A lot will depend on the composition and speed of the ISM, but even the majority of that material could in fact 'pass trough' the 'collision' process.

The more I think about it, the images don't even actually tell me anything more than most of the materials passes through the collision process. Period. A lot of that mass could be in the ISM or in bodies in the solar system infrastructures, but the lensing data does seem to suggest that "collisions" are more of a 'pass through' process when the momentum and angular directional components are favorable.

 

[DeiRenDopa]

Are you sure?

Positive. You and I don't have the technology necessary to see 'everything' in a galaxy. We subjectively 'interpret' a whole lot based on a limited set of data.

Sigh.

Doin' the Gish Gallop again are we MM?

"All you know is that our technologies are limited and you can't "see" all the matter in a galaxy" - that's your claim.

Now, what do you understand by gravitational lensing, MM? After all, did you not say you were a card-carrying member of the Einstein GR club?

Other readers: yeah, I know, we've been here, done this, got a dozen t-shirts ... if MM keeps up with this blatant dishonesty, I'm done ...

Can you describe a distribution of normal matter, in a rich cluster of galaxies, which is consistent with all relevant astronomical observations?

Nope, and neither can you which is why you're stuffing the gaps with "dark matter".

Thank you.

But I thought you declared astronomy not science, seeing as you can't test anything much "in the lab"; you did do this, didn't you?

Yet another demonstration of your subjective, inconsistent worldview?

Where's the science MM?

If you can't, what objective, independently verifiable basis is there for your claim?

My claim of what?

That all you need is normal matter (no CDM required).

All I know is we have relatively primitive technology that limits our capabilities. We can't account for all the mass in a galaxy based on our current mass estimates. So what? None of these facts necessitates new and exotic "made up" matter with ad hoc properties galore. I'd say it's time to "scrap" the mass estimation techniques and start over again.

And I'd say it's time for you to stop being willfully ignorant, and go learn some astronomy.

Wait ... you ignored this suggestion, what, a dozen times or more; OK, forget it.

If you discount such observations, why do you bother writing posts about astronomy?

You're putting a very odd 'spin' on statements (again). I don't discount the observations of "missing mass". I "discount" your belief that you already know/knew exactly how much "normal" matter exists in any given galaxy in any of those lensing studies. All you can do here is use "flawed" mass estimation techniques, and then compare it to the lensing data "measurements", and thereby "test" your mass estimation techniques. They *FAILED MISERABLY*. Let that mass estimation technique die a natural death and try again.

Dude, no one has tested gravitational lensing, by ~sol mass objects (much less ~trillion sol mass objects), "in the lab", so how do you know anything?

Remind me again, please, what are the allowable limits of extrapolation (of theories such as GR, from "in the lab" tests)?

If you *insist* on sticking with your old and "failed" theories of "normal mass" estimation, and want to call the difference "dark matter", ok. Don't however turn around and pretend your failed mass estimation techniques were valid all along and the difference is made up of "exotic matter" with ad hoc properties galore.

You could care less about what I - or anyone else - does, wrt astrophysical analyses ... you are trying to show - using your subjective, idiosyncratic, inconsistent approach - that all relevant astronomical observations can be accounted for - quantitatively - with distributions of normal (baryonic) matter.

So far, you have failed - miserably - to do so.

 

[Michael Mozina]

Now, what do you understand by gravitational lensing, MM? After all, did you not say you were a card-carrying member of the Einstein GR club?

I know enough about it to believe that it works as advertised in the sense that matter will cause a curvature of spacetime that can act as a lens in some cases. I'll even go so far as to let you use that method to "test" your "galaxy mass estimates". Oh look, according to the lensing data, your mass estimate technique failed miserably. Now what?

 

[DeiRenDopa]

Now, what do you understand by gravitational lensing, MM? After all, did you not say you were a card-carrying member of the Einstein GR club?

I know enough about it to believe that it works as advertised in the sense that matter will cause a curvature of spacetime that can act as a lens in some cases. I'll even go so far as to let you use that method to "test" your "galaxy mass estimates". Oh look, according to the lensing data, your mass estimate technique failed miserably. Now what?

Huh?

Lensing observations tell you what the mass of the lens is (and, in some cases, its distribution).

These observations, combined with many others (of several different kinds), are consistent with the existence of a great deal of 'non-baryonic' (not normal), cold mass. The distribution of this kind of mass is consistent with it having a very low electromagnetic cross-section, i.e. behaving as cold, dark, collisionless, mass.

And, let's not forget, consistent ... quantitatively.

Which brings us right back to the paper you're working on ... showing that the amount of, and distribution of, normal matter (in rich clusters, galaxies of many kinds, etc, etc, etc) required to be consistent with the lensing observations is such-and-such, AND showing that this amount, and distribution, is consistent with ALL relevant other astronomical observations ...

How's that paper coming on, MM?

 

[Reality Check]

You're a trip. I have not 'avoided' you on this issue at all, in fact I've been in your collective face about it for years. In all that time not one astronomer has been able to round up even a single gram of this magic matter stuff, and yet you expect me to believe you anyway.

I will post it here so everyone can see the simple question that you have been avoiding for 3 months.

It tells you *nothing of the sort*! You simply *assumed* that it is not "normal matter". All you know is that our technologies are limited and you can't "see" all the matter in a galaxy. Big deal. Nothing unusual there.

The assuption is that normal matter acts normally. The IGM interacts gravitationally and electromagnetically. The other stuff in the colliding galaxic clusters does not interact electromagnetically. That is not normal

Well, I 'sort of' agree with you, at least in the sense that it is still relevant and necessary to explain the "missing mass'. Again however there is zero empirical evidence that any of that missing mass is anything other than 'normal matter'.

There is no missing mass. Gravitational lensing has given us good maps of the mass distruction in galactic clusters. The colliding galactic clusters have separated the IGM from the dark matter and shows that dark matter interacts weakly or not al all with normal matter.

Actually no, I said they were more abundant than you realize and most of your "missing mass" tracks with the solar system infrastructure according to the lensing data.

What lensing data?

The lensing data that I have supplied to you is about galactic clusters.It shows that most of the mass in a galactic cluster is

1. Not in the galaxies.
2. Not in the intergalactic medium.

Well duh! If two solar systems pass by one another at a couple millions of miles per hour at a couple light years distance, they aren't likely to interact with each other "strongly". In fact they may hardly interact at all. Again, let me state emphatically that you know absolutely nothing at all about the composition of that unknown material based on this information..

Well duh! ou ignorance is astounding.
Astronomers know this. They know that when galxies collide the solar systems in themn do not collide and do not interact "strongly".
But one more time:
Let me state emphatically: The observations are of the colliding intergalactic medium in colliding galactic clusters.
Is that loud enough for you?
Can you read that?
Do you understand that the observations are nothing to do with solar systems?

 

[Reality Check]

Can Micheal Mozina answer a simple question

First asked 18 July 2009
Here is the question:

1. A is a big blob of gas.
2. B is a bib blob of gas.
3. Blob A hits blob A.
   • If the gas is all the same stuff then the result will be another blob of gas.
     It is probable that some of the gas will not not collide. In that case there will be blobs of gas to each side. The size of these outlying blobs will reflect the amount of gas that did not collide. See the point below about why insignificant amounts of normal (baryonic) matter will not collide.
   • If the gas is a mixture of two kinds of gas , one of which interacts weakly with the other, then the result will be 3 blobs since the weakly interacting gas passes through the other gas.
     The size of these outlying blobs will reflect the amount of gas that did not collide plus the amount of weakly interacting gas.
4. We see 3 blobs.
   The outlying blobs contain most of the matter in the bolbs A and B.
5. Thus the gas is made of two kinds of gas, one of which interacts weakly with the other.

Any problems with this analysis with what is going on with the majority of the matter in the Bullet Cluster and MACS J0025.4-1222 (and even Abell 520)?

Remember that astronomers can calculate the probability of atoms in the ICM colliding as they travel millions of light years through each cluster. I do not know the exact number but expect it to be high (an atom travels millions of light years through a medium containing about 1 atom per cubic meter - you do the math!).
Thus the amount of gas that did not collide is tiny. The outlying blobs are thus mostly weakly interacting gas, i.e. particles that collided but did not interact strongly.

If you cannot find any problems then you agree that these three observations are evidence that there is matter that does not interact like baryonic matter. This we call nonbaryonic matter.