Dark Matter

[athinker]

JMJones0424,

 

"Observations" exist in variety. The rotational speed is a variety of observation. The radiational effects are another. The rotaional speed is a physicaly reliable measure of mass as you would have to adjust the laws of motion according to Newton if it were not. As far as any certain measure it is reliable. (Except for high G areas like very near the sun. That is not the case we are talking about here). In fact the "dark matter" concept itself is acknowledgement that the mass of the galaxy is distributed not concentrated in the center like the solar system. There is no argument there. The issue is not a rotational problem. My argument is it is a misnomer to call it a rotational anomaly. The rotation is what it is. The issue is that the mass in the core is more luminous by mass than the mass in the disk. The current fad of calling the less luminous mass in the disk exotic "dark matter" that we have never seen before overlooks the issue of why matter is luminous to begin with. There are many misrepresentations of the issue that say most of the mass of the galaxy is in the disk. This is not born out by any obsevation whatsoever, rotational or otherwise. Let alone that any mass is made of dark matter.

 

The mass distribution graph is derived from the flat rotational graph of opticly observed stars and gas clouds. We measure the rotational speed of a star or gas cloud near the edge of the galaxy. from this we can know the mass of the galaxy inside the orbit of the star. We then measure the rotatinal speed of a star 5000 light years closer to the center and from that we can derive the mass of the galaxy inside of its orbit. We subtract that mass from the mass derived from the outer star's speed and get the mass of the "ring" between the edge star and the inner star. We divide that mass by the area of the ring to get a mass concentration. We do this in concentric rings to the center to get the mass distribution. If we did the same thing with the rotational speeds of the planets of the solar system we would find that 99% of the mass is inside the orbit of Pluto and also inside the orbit of Mercury. We would therefore know that there was very little mass between Pluto and Mercury. Even if there was an object in the orbit of Mars ten times the size of the sun we would know it was very low mass. We would know it was a gas cloud or something.

 

There don't need to be numbers to the sides of the graph because this mass distribution graph would be the same for any disk of matter with a flat rotational velocity curve.

[JMJones0424]

My argument is it is a misnomer to call it a rotational anomaly. The rotation is what it is. The issue is that the mass in the core is more luminous by mass than the mass in the disk. The current fad of calling the less luminous mass in the disk exotic "dark matter" that we have never seen before overlooks the issue of why matter is luminous to begin with.

 

OK, I think I understand your approach now. Of course, the rotational anomaly exists only if you start from the assumption that the mass of the galaxy being observed can be correctly derived from "luminous mass" (which you have previously clarified to mean any matter that can be observed through electromagnetic interactions, elsewhere referred to as baryonic matter (?)). If you make your baseline the observed rotational velocity, then obviously there is no anomaly with observed rotational velocity. Please note, that while scale is not required, labeling the two axes would have made it a lot easier for me to grasp the first time what you were representing. Regardless, I think I have a grasp of the graph now.

 

The mass distribution graph is derived from the flat rotational graph of opticly observed stars and gas clouds. We measure the rotational speed of a star or gas cloud near the edge of the galaxy. from this we can know the mass of the galaxy inside the orbit of the star. We then measure the rotatinal speed of a star 5000 light years closer to the center and from that we can derive the mass of the galaxy inside of its orbit. We subtract that mass from the mass derived from the outer star's speed and get the mass of the "ring" between the edge star and the inner star. We divide that mass by the area of the ring to get a mass concentration. We do this in concentric rings to the center to get the mass distribution

 

So, it seems to me that if you were to take any y value in your graph and compare that mass with the amount of mass that we can observe through electromagnetic interactions at distance x from the galactic core, you should find that your mass value y is on average considerably higher than the "luminous mass" that we observe, right? This then is the mystical dark matter. So as you have constructed it, there is not a rotational anomaly, but rather a "luminous mass" anomaly.

 

I don't see how this changes the problem fundamentally though, as rotational velocity and mass are linked. While your graph is different, there is still the question of missing mass, a whole heck of a lot of it.

 

I still don't understand what you propose makes up the missing mass. It appears to me that you are counting on interstellar gas, while this can be ruled out by observation. Or am I still misunderstanding you?

[athinker]

JMJones0424,

 

The issue is how we detemine what luminance value a particular quantity of mass should have. If we arbitrarily assume that all baryonic mass, regardless of its density, distribution or intrinsic luminosity is the same as any other quantity and we compare the luminace value of core mass to disk mass regardless of their intrisic luminosities assumiing them to be the same and we find they are not then we have the problem that we have.

 

The problem is in defining all baryonic mass as having the same luminance value. It doesn't.

 

If you define baryonic matter that way then any matter that doesn't have the same luminosity is dark matter.

 

Just to be sure I understand your position. How do you define dark matter?

 

How do you define the "rotational problem" or "luminosity problem"?

 

To be clear, I'm not saying there is any "missing mass" to be accounted for by closer examination for interstellar gas or the invocation of dark matter. I'm fine with assuming that astro science knows exactly how much baryonic matter there is in the disk and the core.

 

There is missing luminance in comparing the disk to the core which can be accounted for, but is not being accounted for, by higher fusion to mass ratios in the core. Higher intrinsic luminosity of matter in the core due to fusion. Even if you say that only 10% of the mass in the core is stars then comparing it to mass in the disk where only 2% is in stars would give you missing luminosity in the disk compared to the core. If you say the non stellar matter in the core is hotter than the disk, same thing. All normal matter.

[JMJones0424]

Alright, now we're getting somewhere! I feel I understand where you are coming from now.

My definitions... I think they are relatively standard?

Dark matter is all matter that is transparent (invisible, non-existent, non-interacting, etc.) to electromagnetic forces. I assume that it is also unaffected by the strong and weak nuclear forces, but I may be way off base there.

 

Baryonic matter is all matter that is not dark matter, or all matter that is affected by electromagnetism.

 

How do you define the "rotational problem" or "luminosity problem"?

This is two sides of the same coin. We have two observations that are theoretically linked, however at least one of these three things must be incorrect. Either A.) our audit of the quantity of matter is incorrect (if matter is limited only to baryonic matter), B.) our observation of rotational velocity of almost every galaxy and cluster of galaxies must be incorrect, or C.) our theory on how we relate mass to rotational velocity must be incorrect.

 

Dark matter proponents obviously hold that option A.) is invalid; MOND and other theories propose C.) is incorrect. You appear to agree with B.) and C.), but take a different path on A.), and this is where I am still unclear on what you are saying. If you start by measuring mass distribution based on rotational velocity, you should end up with far more mass than is observable through electromagnetic interactions. This is equivalent to starting with the amount of mass that is observed to interact electromagnetically, and then determining that it is insufficient to produce the observed rotational velocity.

 

Are you calling into question stellar nuclear physics? What exactly are you proposing accounts for the tremendous disparity in observed mass due to rotational velocity (and, importantly, also through gravitational lensing) and observed mass due to electromagnetic interactions?

 

The problem is in defining all baryonic mass as having the same luminance value. It doesn't.

Please elaborate, as I don't understand what you mean here.

 

Thank you for taking your time with me, but I must get some work done today, I will be awaiting eagerly your response this evening.

[athinker]

JMJones0424,

 

 

 

 

I'm having a problem understanding you. Mainly because your definitions are circular. Tall men are not short, short men are not tall. True though that may be it's sophistry as far as the question I asked.

What I disagree with is the claim that astrophysicists are detecting, by a correct interpretation of the luminosty distribution of its baryonic interactions, all the baryonic matter that exists in the galaxy.

 

What they appear to be saying, what I disagree with, is that all baryonic matter has the same luminosity to mass ratio. I disagree that they are correctly calibrating their interpretive conclusions about the baryonic matter interactions to mass ratios in the disk without addressing the fact that there are, by a higher fusion to mass ratio in the core, more baryonic matter interactions to mass, and therefore more luminance to mass, in the core than in the disk.

 

Before they can say that there is some unusual non baryonic matter they have to show very conclusive evidence that the mass that is being detected by newtonian physics cannot be accounted for by conclusive baryonic evidence. The evidence they are presenting is not conclusive as they are not addressing the cause of varying baryonic observables, radiation from baryonic interaction, variable mass to fusion ratios

 

I'm not even discussing other invocations of "dark matter" astrophysicists use to solve other mysteries. Only the "galactic rotation problem".

 

You say

"This is equivalent to starting with the amount of mass that is observed to interact electromagnetically, and then determining that it is insufficient to produce the observed rotational velocity."

 

No it's not. Are you playing with me? Yes, by observing an object like a star or gas cloud by its light I'm observing it "to interact electromagnetically". But I'm not starting with its electromagnetic interaction to determing its mass. I'm using specific point like object's "electromagnetic interactions" to determine its position and its motion. It could be massless as far as I care. I'm using its position and motion to determine the mass of something else, the mass inside its orbit.

 

Except for those who erroneously say that most of the mass of the galaxy is in the disk I have no disagreement with the amount of mass in the galaxy or the distribution of mass as computed by an analysis of the rotational curve. I disagree with those who conclude that astropysicists are properly calibrating their conclusions about their "electromagnetic interaction" detection method.

 

Would yoiu agree that if there is a higher fusion to mass ratio in the core than in the disk that there would be a higher luminance to mass ratio in the core as well? Would you agree that a conclusion about the luminance to mass ratio in the disk that does not address the facts about the cause of the higher luminance to mass ratio in the core but is using the luminace to mass ratio in the core as a referance come to a conclusion about the luminance to mass ratio in the disk that is an erroneous conclusion?

 

For future referance when I write luminosity I'm talking about electromagnetic interaction, detectable baryonic interaction even if it's undetected or not detected properly or the detection is not interpreted properly.

 

I didn't answer your question about A B and C because A is a misstatement of the issue and I disagree with B and C. I don't agree that B and C are the only options. I can't even say that I disagree with A as I don't understand your statement of it.

[ken hughes]

Thinking,

 

Like you, I am sceptical about the existence of CDM. As you correctly point out, it cannot be justified by the analogy of Neptune, since with Neptune, we simply "created" another planet, an additional known entity, whereas with CDM, we are "creating" an entirely new entity altogether with some very specific and demanding properties. This is a bit like the Aether before Relativity came along and we know what happened to the Aether.

Also, this "creation" goes against the guidance of Occam's razor and we have seemingly failed to pursue other explanations which do not demand the creation of new entities or the violation of known fundamental rules of behaviour. The correct interpretation of Occam's razor is not the usual "The simplest explanation is usualy the correct one", or even that "Entities must not be multiplied beyond necessity", but that "For two equally valid theories giving the correct answer, the one with the least number of new creations and which best matches known science, is usually the correct one".

I submit that the claim of CDM best matching known science is tenuous to say the least. Breaking Newtons law and having no fit within GR is clearly no good match at all.

 

The other supporting "evidence" from gravitational lensing and the 3 degree background radiation is also suspect and these could be explained in other ways if only we would try. It is simply convenient to match them all up with the CDM proposal. In principle, it is not very scientific to claim that one idea must be true just because other observations can be explained using the same envisaged mechanism. It blocks any effort to challenge the initial proposal and we might even suspect this is deliberate.

 

The challenge then is to come up with the fundamental cause for the rotation speeds that matches known science and then to calculate and confirm the observational speeds. This will have to happen before anyone in the established scientific community will even listen.

Coming up with the fundamental cause is simply a matter of applying known science and deducing what it must be. Let's try it;-

 

 

Firstly, we ask, "Is the anomaly real or is it an illusion?" The answer is it could be either or both, so let's park that one for the moment and come back to it later.

 

Secondly, "What are the available mechanisms?" Science and scientific progress is always about cause and effect but we seem to have lost sight of this in recent years.

The answer, I think we would all agree, is that it is the action of gravitation that causes the orbital motion of any entity.

 

The next question is "What causes the motion not to be, or to not appear to be, in accordance with Newton?", and this is where we have invented CDM to explain the deviation. If we now use the guidance of Occam's razor, we cannot invoke CDM and must look elsewhere or in more depth to resolve the issue.

 

The next question becomes "How can Newton's Law result in the observed rotation speeds?" and to answer this we need to use our powers of thinking, of deduction, our intelligence. We must depart from conventional wisdom into the realm of original thought. Even the fact that we are looking for an "alternative" solution seems, these days, to invoke distain from the scientific community but science and scientific progress always involves "alternatives" and if we stifle the exploration of these, we stifle scientific progress itself.

 

We might re phrase the question;- "How can Newton's Law AND the observed rotation speeds, both hold?" After all, this is the best fit with known science if we can find an answer,

 

There is only one way for this to be the case and that involves the effects of time dilation. Now, our first reaction to this idea might be that time dilation is a very tiny phenomenon and would surely have no significant effect on rotation speeds. Well, that may or may not be the case but we should not throw in the towel just because the numbers MIGHT not work. Let's get the principles established first. The theory will stand or fall when we apply the correct math.

As encouragement for you to persevere with this proposal, I suggest that although the time dilation decaying to zero at infinity has very small values indeed, the distances involved are nevertheless immense and the sheer scale of observations will make this effect more significant. In other words, the very small time rate differentials accumulate over the vaste distances and will have a noticable effect on rotation speeds.

 

Rotational speeds in any two frames can both conform to Newton within the frames themselves, whilst they may not appear to conform relatively between the frames if the time rates are different in each frame. This way, any speed we observe from the galactic center outwards will be distorted by the time rate field of the galaxy itself. Speeds will be red shifted or slowed down near the centre and outwards, relative to the intergalactic frame.

 

The next question "Is there any radial position that gives us an non distorted Newtonian predicted speed?" The answer is yes and this position is the place at which the time rate is the same as here on Earth and there is no temporal distortion of events relative to our frame when we observe stars at this radial position.

If we look at a galaxy of similar size and mass to the Milky Way, then this "Datum" position will be at the same galactic radius as the Solar system's in the Milky Way.

The Newton curve, therefore MUST pass through this point on the observed curve, so that we observe the non distorted Newtonian prediction at that radius.

 

This means we have to raise the Newton curve upwards on the graph such that it passes though this Datum point which also has to lie on the flattened observed curve at the datum radius. The shape of the Newton curve will also change slightly, due to the implied increased mass at the galactic centre. We deduce that the effective central mass of the galaxy is much greater than currently envisaged for it to produce these increased rotation speeds. The central, supermassive black hole must therefore be more massive to produce this effect. However, so far, we have only raised the curve and NOT flattened it. The curve is presently higher than observed INBOARD and lower than observed OUTBOARD of the Datum. (See my Utube video "Answer to the galactic rotation anomaly")

 

The flattening of the curve from this raised Newton curve, is due to the red shifted (reduced)speeds INBOARD of the datum position and the blue shifted (increased) speeds OUTBOARD of the datum. We have a hint of this causality from the Pioneer anomaly, in that there is a very small blue shift (increased speed) due to the time rate differential between the probes and the Earth. It is the same phenomenon as galactic rotation distortion, but on a very much smaller scale and therefore with very much smaller effects.

 

Using this logic and the appropriate math, I get the flatteneing effect on the Newton curve to match the observed. If you plot the Newton curve through the datum position with the observed curve from "www.astronomynotes.com, it becomes obvious from just looking at the shape of the curves.

Short report submitted to PHYS.Rev.Lett

[CraigD]

But have no fear. I have e-mailed the discoverer of the galactic rotation problem and asked her if she has considered the fusion issue. I doubt if she'll write me back but you never know.

Athinker, do you mean you’ve sent an email to Louise Volders?!

I don’t see that you’ve answered this non-technical question, athinker. Have you actually made an effort to contact Volders, or am I guilty of my common error of taking statement too literally, and you meant to be rhetorical, not factual?

[CraigD]

Welcome to hypograph, Ken! :)

 

... I am sceptical about the existence of CDM. As you [athinker] correctly point out, it cannot be justified by the analogy of Neptune, since with Neptune, we simply "created" another planet, an additional known entity, whereas with CDM, we are "creating" an entirely new entity altogether with some very specific and demanding properties. This is a bit like the Aether before Relativity came along and we know what happened to the Aether.

Also, this "creation" goes against the guidance of Occam's razor …

I think everybody concerned with “missing mass” problems or several scales – local (eg: the stability of the solar system, the “Kuiper cliff” problem), galactic, and trans-galactic – amateur and pros both, are skeptical of every theory addressing them. None of them are, in my experience, very satisfying, including ones that suggest there’s no missing mass to be found, but rather “weird gravity” (eg: MOND), though my intuition inclines me toward a “weird theory”. All having flaws and assumptions offensive to ‘ole Bill of Ockham and his disciples (present company included), their adjudication seems more a process of deciding which theory’s flaws are least offensive rather than which’s predictions are most accurate.

 

The CDM variation of the we-can’t-detect-it matter family of theories is by most accounts best accepted, but still full or well-acknowledged flaw. It’s the tentative beginnings of a theory, a decision to try this direction, not a mature theory with which to produce predictions to be tested with increasing scrutiny and precision.

 

Fundamentally, all questions of gravity are IMHO hampered by the lack of a computationally usable (eg finite-termed) solution to the n-body problem. Modeling gravity-dominated systems is simply hard, and in the absence of models agreeable to everybody to inform them, theoretical explanations of unexpected observations feel ad-hoc to me.

 

On a bright note, computing resources get greater and cheaper all the time, so the intractability of calculable exact mathematical solutions of any gravitational motion theory is less of a hindrance than it would otherwise be. I love computers :)

 

... Using this logic and the appropriate math, I get the flatteneing effect on the Newton curve to match the observed. If you plot the Newton curve through the datum position with the observed curve from "www.astronomynotes.com, it becomes obvious from just looking at the shape of the curves.

Short report submitted to PHYS.Rev.Lett

Cool!

 

Can you post the salient points of your math – a how-to-reproduce guide for the so inclined? I hope you agree that proof by “it becomes obvious from just looking at the shape of the curves” is a bit to informal. ;)

[athinker]

If you're interested in the formula I used to calculate my conclusion, not therory, about the rotational curve I used Newton; v<SUB>cir</SUB> = sqrt GM/r with the circular velocity v<SUB>cir</SUB> = km/s, the gravitational constant G in solar masses, M = number of solar masses and radius r in light years.

 

If you want to play with calculations to confirm my conclusions yourself I can recomend this easy to use online calculator that uses this formula. http://orbitsimulator.com/formulas/vcirc.html

 

This hypography forum spikes your browser so it won't read html tags. If you have a problem reading html tags just copy the text to a text editor, save as an html or save as txt then rename the file replacing the dot txt file type with dot html tag and open it in another browser window.

 

By the way, the n body problem is not significant in this case. It's only significant if calculating n>2 bodies in n>2 motions. IE random initial conditions. Turbulent initial conditions of motions. Orbital planes at random angles, random masses, random velocities, random distances etc. For any number n more than 2 it is exponetially more difficult. Then it is computationaly difficult. That's not the condition here. The bodies are moving in the same circular plane. Although the galaxy is made of many bodies they can be treated as one body relative to one orbiting body. n=2 so the n body problem doesn't exist in this case.

[CraigD]

Some pragmatics and an administrative apology:

 

This hypography forum spikes your browser so it won't read html tags. If you have a problem reading html tags just copy the text to a text editor, save as an html or save as txt then rename the file replacing the dot txt file type with dot html tag and open it in another browser window.

Hypography has used 3rd party forum software since its creation. It’s currently using IP.Board. All sensible such software prevents the direct injection of html, some by simply escaping all of it, (if you look at the source of the current page, you’ll notice IP.Board has simply changes “<...>” strings into “<...>” ones), some by escaping all but a safe subset of it. IP.Board allows you to markup your post text with the BBCode alternative markup language. Many BBCode tag and html element names coincide, so for practical purposes, if you’re accustom to using simple html elements like <sub>, just replace them the <> braces with [] ones, eg:

instead of X₀,

write X₀

to show X₀.

Frequently used tags can be added using the buttons above the post entry form.

 

Hypography has a LaTeX:math renderer installed, so if you know a little (or a lot ;)) of LaTeX, you can easily enter math using math or imath tags, eg:

[math]V_{cir} = \sqrt{\frac{GM}{r}}[/math] to show

 

[math]V_{cir} = \sqrt{\frac{GM}{r}}[/math]

 

The LaTeX:math package is documented and explained many places. My favorite reference is Wikipedia’s Help:Displaying a formula page, my favorite tutorial this one by John Forkosh.

 

Now the apology: We at hypography don’t make the above very easy to discover. Instead of from following a prominent “how to format your posts” link, folk must learn about BBCode and LaTeX at hypography by either inspecting (by clicking the reply button) posts with nicely formatted text, or from posts like one. Not the most user-friendly experience, IMHO, though perhaps a social filter of a sort – since it takes a bit of effort to learn, nice formatting in posts confers a subtle status boost.