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You probably want to put on your skeptical goggles and set them to maximum for this one. An Italian mathematician has come up with some complex formulae that can, with remarkable similarity, mimic the rotation curves of spiral galaxies without the need for dark matter.
Currently, these galactic rotation curves represent key evidence for the existence of dark matter – since the outer stars of spinning galaxies often move around a galactic disk so fast that they should fly off into intergalactic space – unless there is an additional ‘invisible’ mass present in the galaxy to gravitationally hold them in their orbits.
The issue can be appreciated by considering the Keplerian motion of the planets in our Solar System. Mercury orbits the Sun at an orbital velocity of 48 kilometers a second – while Neptune orbits the Sun at an orbital velocity of 5 kilometers a second. In the Solar System, a planet’s proximity to the substantial mass of the Sun is a function of its orbital velocity. So, hypothetically, if the Sun’s mass was reduced somehow, Neptune’s existing orbital velocity would move it outwards from its current orbit – potentially flinging it off into interstellar space if the change was significant enough.
The physics of the Milky Way Galaxy is different from the Solar System, since its mass is distributed more evenly across the galactic disk, rather than 99% of its mass being concentrated centrally – the way it is in the Solar System.
Nonetheless, as this past Universe Today article explains, if we assume a similar relationship between the cumulative mass of the Milky Way and the orbital velocity of its outer stars, we must acknowledge that the visible objects within the Milky Way only have 10-20% of the mass that is required to contain the orbital velocity of stars in its outer disk. So we conclude that the rest of that galactic mass must be dark (invisible) matter.
This is the contemporary consensus view of how galaxies work – and a key component of the current standard model of the cosmology of the universe. But Carati has come along with a seemingly implausible idea that the rotational curves of spiral galaxies could be explained by the gravitational influence of faraway matter, without needing to appeal to dark matter at all.
Conceptually the idea makes little sense. Positioning gravitationally significant mass outside of the orbit of stars might draw them out into wider orbits, but it’s difficult to see why this would add to their orbital velocity. Drawing an object into a wider orbit should result in it taking longer to orbit the galaxy since it will have more circumference to cover. What we generally see in spiral galaxies is that the outer stars orbit the galaxy within much the same time period as more inward stars.
But although the proposed mechanism seems a little implausible, what is remarkable about Carati’s claim is that the math apparently deliver galactic rotation curves that closely fit the observed values of at least four known galaxies. Indeed, the math delivers an extraordinarily close fit.
With skeptical goggles firmly in place, the following conclusions might be drawn from this finding:
• There are so many galaxies out there that it’s not hard to find four galaxies that fit the math;
• The math has been retro-fitted to match already observed data;
• The math just doesn’t work; or
• While the author’s interpretation of the data may be up for discussion, the math really does work.
The math draws on principles established in the Einstein field equations, which is problematic as the field equations are based on the cosmological principle, which assumes that the effect of faraway matter is negligible – or at least that it evens out at a large scale.
Perplexingly, Carati’s paper also notes two further examples where the math can also fit galaxies with declining rotational velocities in their outer stars. This is achieved by switching the sign of one of the formulae components (which can be + or -). Thus, on the one hand the effect of faraway matter is to induce a positive pressure that contains the rapid rotation of stars, preventing them from flying off – and on the other hand, it can induce a negative pressure to encourage an atypical decay in a galaxy’s rotation curve.
As the saying goes, if something seems too good to be true – it probably isn’t true. All comments welcome.
Further reading:
Carati Gravitational effects of the faraway matter on the rotation curves of spiral galaxies.
My take on dark matter is, that it is a miscalculating, stemming from our presumption that the speed of light is constant.
What if the speed of light varies through time and space?
That creates some interesting theory, at least I think so.
Antimatter is the mind and consciousness of all living entities.
You are your own universe.
Reality is where the minds (antimatter) meets the physical universe.
Interested? Then read my philosophical multiverse theory.
Google crestroyer theory and find it instantly
http://crestroyertheory.com/the-theory/
No, I’m not interested in incoherent crackpot nonsense. Thanks all the same though.
Are you on drugs?
Conclusion… this guy has just had a head explosion, because antimatter destroys matter on contact. I’d advise no one shakes his hand – Boom! Just like that!
Your metaphysical points of view are out. We am only interested in Quantum Multiversal interpretations.
So there could be a whole, entire little universe on the tip of my finger…? Wow! … Can I buy some pot from you?
That the vacuum speed of light is constant is thoroughly tested.
Antimatter destroys matter, so can’t make up minds. Minds are produced in most people by their brains. If you feel otherwise, you are welcome to it.
“You are your own universe.”
Dogs are your own universe, cats are your own universe, … I do not think it means what you think it means.
A Mathematician, a Biologist, and a Physicist are sitting in a street cafe
watching people going in and coming out of the house on the other side
of the street. First they see two people going into the house. Time passes.
After a while they notice three persons coming out of the house.
The Physicist concludes: “The measurement wasn’t accurate.”
The Biologist concludes: “They must have reproduced.”
The Mathematician concludes: “Now, if exactly 1 person enters the house, then it will be
empty again.”
LOL! I had to copy that one down. Thanks!
A Mathematician, a Physicist and a Statistician arrive for a job interview. The mathematician is interviewed first. After having a good interview the final question is, “what is two plus two?” Responding, “four” says thanks and leaves. The physicist goes through the same interview with the same final question. Responding, “a little less than 4.0001 and more than 3.9999,” says thanks and leaves. The statistician finishes the interview with the same last question. After looking over one shoulder, then the other, leans forward and asks, “what do you want it to be?”
Who is this Carati? He isn’t identified in the article. Does he have a first name? What is his background? Where does he work? Male or female?
I think that this may be the dude in question.
You can find that in the linked PDF: Andrea Carati (male name in Italy) from the University of Milan.
His name and place of employment are footnoted on pg1 (Maths Dept.- University with long name in Italian).
The Bullet cluster data pretty much supports dark matter, and I don’t see how this type of model can reproduce that. This seems to be the latest in the MOND development.
LC
However, the Bullet cluster does not necessarily only support the dark matter hypothesis, it will support other theories too, along with all the other evidence for dark matter. I agree that this model would likely fail to describe every scenario, but it is encouraging to have others thinking outside the dark matter box.
What lcrowell says, perhaps vaguely, is that cluster data supports dark matter while others can’t “reproduce that.” And that is true, see my other comments: other models fail to predict _all_ cluster data in their totality.
It is not encouraging to me that people flog a now dead horse. (Again, see my other comments on that.) It is unhealthy business and unhealthy science.
I knew you would pipe up here. Dark matter has been conceived as a source of gravity – but extra physical substance in some people’s minds is not necessary to explain the phenomena we observe. And, I’m sorry, it IS encouraging for people to look at ALL possibilities. Take 90% mass of a galaxy, spread evenly through the space it occupies as gas, now take the other 10% mass compressed into stars – do you just assume this would have the same gravitational effect as 1/9 of the gas? Anyway, whatever your thoughts are on that, more importantly, even if DM does exist, you seem to have completely closed your mind to MOND (or laws which actually don’t reference Newton at all!). I am as excited about DM as the next guy, but it doesn’t fill all the gaps. Also, don’t be a party pooper.
I wanted to correct your misrepresentation of what lcrowell and others, quite correctly, says on this, that MOND type theories can’t reproduce this without problems. This has been known for a fairly long time.
If you think otherwise you can present references on how they get around relativistic problems.
No one ‘completely closes’ their mind on possible hypotheses. (On impossible, certainly.) MOND had its chance, but eventually it failed. Similarly with DM, but it didn’t fail and it has been successful in predicting more and more structure.
I am serious about this: After the Eris simulation there is simply no gap left for alternates that can’t predict _as much or more_ as Duncan Ivry says. MOND isn’t among those because a) it only managed individual galaxies b) it is now known that most or all instants of it has fundamental problems. It is unlikely that any MOND theory would get around that.
And I am serious about this: It is generally unhealthy to keep flogging a dead horse. Astrology failed, epicycles failed, MOND failed, not because they weren’t predictive so totally wrong, but because they couldn’t predict nature so factually wrong. No one knew that at the outset, it was eventually learned.
You don’t have to agree that MOND is dead of course. But you should be aware that “encouraging” isn’t what all others think of this, and preferably why. Because this isn’t a party.
You don’t need to correct any ‘misrepresentation’. And don’t try to veil yourself sounding like you’re being pitiful! ‘Oh, you poor, poor caveman who can’t understand the truth’. For future reference I’d rather not communicate with people who make snide remarks like that – makes me think the same of you. Enjoy.
My point exactly. It may be a good model for now, but that is no indication at all that it will remain so. To imply that “the science is settled” is as silly in this case as it is in other areas.
> To entertain this is now an unhealthy business and unhealthy science.
So what you’re saying is: We have one theory that can’t be verified yet, but seem to explain things pretty good. That means that every scientist on the world should only work on that one and that one alone. No one should think about or experiment with ANY other theory concerning the same subject at all.
I have to say that your and my idea of the scientific process somewhat diverge…
Has anyone noticed the parallels that exist between today’s cosmology and that of geology in the early and mid parts of the twentieth century?
Go back and geologists then had a data problem that should have led for a hunt for hidden “dark energy” forces within the Earth. But instead geologists hounded Alfred Wegener and ignored all the evidence he collected that some slow powerful force was moving and breaking the continents apart. Today’s cosmologists are not making that mistake with today’s inexplicable data.
But will the eventual understanding of today’s “dark matter” yield a phenomena so radically changing of our fundamental concept of the universe as that of the Earth created by plate tectonics?
Such as dark matter is gravity “leaking” from another universe?
Possibly – I think there are some plausible ideas being floated suggesting that the density waves in spiral galaxies contribute to the flattened (non-Keplerian) rotation curves that are observed (by channeling angular momentum outwards). I struggle to visualise how a ‘halo’ of dark matter would achieve this so consistently in so many different galaxies – too much fine tuning seems required.
Nonetheless, the lensing effects of galactic clusters and collisions (Bullet Cluster etc) remain compelling evidence for the presence of substantial invisible matter/mass.
Using Baez crackpot index “for rating potentially revolutionary contributions to physics”, I afford this thread:
1. A -5 point starting credit.
35. 40 points for comparing yourself [the topic] to Galileo [Wegener], suggesting that a modern-day Inquisition is [not] hard at work on your case, and so on.
Sums to 35 points. =D
Really, Wegener’s then hypothesis is still unexplained from first principles: the necessary heat fluxes from primordial heat vs radioactivity hasn’t been established. Today there is hope that neutrino experiments will eventually do that:
“… The current total heat flux from the Earth to space is 44.2±1.0?TW, but the relative contributions from residual primordial heat and radiogenic decay remain uncertain. … Taken together, our observations indicate that heat from radioactive decay contributes about half of Earth’s total heat flux. We therefore conclude that Earth’s primordial heat supply has not yet been exhausted.”
This is pretty much the same situation that DM is in. We can predict and test its effects, but we don’t know the details of how to derive it from particle physics. (I.e. which particles we are dealing with.)
It is a good parallel.
Dragan Slavkov Hajdukovic also has a new theory regarding dark matter. “Quantum vacuum and dark matter.”
Quote: “…..the distribution of vacuum polarization will depend on the distribution of matter, so the apparent extra acceleration towards the center of mass will vary from one object to another, and as a function of position within the object,”
Perhaps “Carati’s” equations and Hajdukovic’s hypothesis have some correlations?
http://www.physorg.com/news/2011-11-quantum-vacuum-dark.html
Ooh, I take that!
Yes, the correlation is that it is work on a now dead subject. =D
Mr. Torbjörn are you a DM researcher?!
No, but by now even a layman can conclude that gap theories like MOND are dead, because the gap is closed. See my initial comment.
A contender to DM would need to be at least as predictive. That is a tall order, and all the work on MOND type theories has shown that it is much narrower.
Actually, no. Or rather, yes, a “contender”, or replacement for, DM would likely have to be as predictive. But a disproof of DM would take only a single counterexample. That is what happens to the vast majority of theories, after all.
Well I’m glad that YOU think the all the mysteries of the universe are now solved. I guess everyone should now just forget doing any more research because you say so.
I guess, this is not what Torbjörn said.
It is pretty close to what he said.
In fact the stories and the timing are similar enough that at first I thought this was about Hajdukovic (I hadn’t remembered his name).
But I think the timing and the apparent validation of the math also indicates that DM is not the end-all explanation that some people seem to think it is.
Has Carati tested his proposed mechanism against galaxy cluster data? As far as I’m aware, most attempts to explain dark matter’s effects on individual galaxies without invoking dark matter have been unable to explain the observed effects of dark matter on the scale of galactic clusters.
Good question!
As far as I can see Carati haven’t even tested his mechanism against galaxy data, see my comment above. Carati tested against what the ad hoc hypotheses was designed to predict, but unfortunately for Carati there were other predictions as well.
So are the graphs contrived? It’s implied the ‘theoretical curves’ result from the math – though as I say the fit is extraordinarily close.
Seen from the vantage point of my dark mattress; wearing only my most septic spectacles, I behold my Scale Expanding Cosmetological strap on and fly in the face of the bestial dogma propounded by a veritable orgy of “big bangers”. I shall be compelled to hose you. Conjecture and refutation; The Tentative Solution.
There is not only the problem how stars move in galaxies. The astrophysicist Ethan Siegel some time ago stated it on his science blog “Starts With A Bang” perfectly well, because of which I quote his statements here (a little bit paraphrasing):
“There are plenty of other experiments and observations that confirm Einstein’s General Relativity as the correct theory of gravity. If we want for cosmology to work, too, we need to add dark matter to the theory. This one addition — dark matter — successfully allows us to explain a whole host of observations, including” (1) “the large-scale structure in the Universe,” (2) “the cosmic microwave background,” (3) “the elemental abundances of hydrogen, helium, lithium and deuterium,” (4) “the motion of galaxies within clusters,” (5) “collisions between galaxy clusters,” (6) “the observed expansion rate of the Universe, and” (7) “the internal motions of spiral and elliptical galaxies.”
Yes, a whole host of observations! Any alternative theory of gravity has to explain the seven phenomena mentioned above too. And this is the minimum!
The alternatives to dark matter (DM) died when the Eris simulation showed that dark matter is necessary and sufficient to model galaxies. Then the gap to wedge in “competitors” disappeared.
Now DM predicts all relevant scales of structure formation, from cosmological (the Bolshoi simulation) over clusters to galaxies. And as Duncan Ivry notes, a real competitor would have to predict so much more that standard cosmology with DM is on top of.
If we instead look at these theories as such, they all stumble and fall on the “individual cluster effect”. That is, when they are used for cluster like the Bullet cluster collision they can explain one individual by adjusting the free parameters of the model. But then they fail to explain all others!
The same happens here. Carati hides the parameter adjustments on the “far away matter” contribution by placing them on the local matter (p 14). They are all individual for the “newtonian matter” and their prediction on its distribution is not checked against observation.
Amusingly, Carati tries to resurrect Mach’s principle, a pre-relativity non-predictive hypothesis “that the local motion of a rotating reference frame is determined by the large scale distribution of matter”.
“Frame dragging and conservation of gravitational angular momentum makes this into a true statement in the general theory in certain solutions. But because the principle is so vague, many distinct statements can be (and have been) made which would qualify as a Mach principle, and some of these are false.”
There is no such assumption in general relativity. (What I know of, not having studied it.) The cosmological principle is, as the name hints, a null hypothesis* on cosmology.
More generally, all differential equation models, which Einstein’s tensor equations belongs to, are local models. It is when you integrate them you start to look at global properties in full, such as whether remote sources can be neglected in the studied system.
—————-
* If we accept the modern use of “null hypothesis” to denote the hypothesis to test against instead of the original use, in statistics, of the hypothesis under test.
The cosmological principle is assumed when using the Einstein Field Equations to model cosmology, see for example: http://map.gsfc.nasa.gov/universe/bb_theory.html
Seems we agree now.
Sorry, but that doesn’t follow at all. “Necessary and sufficient” by itself is not strong evidence. It only means that it is a viable model for now. It hardly forms any barrier to something better coming along.
“The less we write about it, the faster the process converges onto healthy science.”
Wow. Man. Are you serious? Are you by any chance a friend of Ned Ludd?
Squelching new ideas (unless you can actually show that they are invalid) is quite the OPPOSITE of what science is about. Sorry if all those upstarts get on your nerves. I doubt your tenure is in much danger.
Too right, it is quite a bizarre way to go about science.
Here’s one for you… the solar systems on the similar plane of orbit act act with their gravitation pulling the rest of the galaxies ‘behind’ to ease rotation and in the simliar function decreasing the warp of space / time ‘friction’ for the proceeeding mass to ease orbit. Similar to how there’s decrease of pressure behind a transport truck lessening resistance directly behind it for vehicles and lowering the energy requred to travel We might be able to see this in solar systems were there planets on the opposite side of the same orbital path….
Fits better than the dark matter / energy / ether / unicorns.
1) Spacetime is not air.
2) The energy the cars behind the truck don’t need is needed by the truck to push away all that air.
So: No.
see addendum..
or if you had a basketball or bowling ball spinning really quickly and then dropped into some fairly well packed dirt… it wouldn’t just sit snug but spin some room making the space around it larger at least until the dirt settled back and it slowed down leaving room for the ball to shift around in the ‘valley’… etc…
Gravitational forces does not work like that.
A galaxy is not a dense packed solid object.
I thought the pro dark matter argument was that galaxies were ‘full of dark matter’ … filling up the spaces where matter didn’t exist? So which is it? is the cup full of dark matter / ether, or is it empty? Or is it we look at these huge collections of mass and energy through such poor instruments over too limited a timeframe, and great distances what we observe would be so distorted, the Fata Morgana would pervade any such analysis.
— I thought the pro dark matter argument was that galaxies were ‘full of dark matter’ … filling up the spaces where matter didn’t exist? —
It still does not form a solid as your example.
I propose we do some experiments. Set off nuclear and or fusion based explosions half way between here and the moon and measure any changes in expected data going to from the Lunar Ranging Retro Reflectors as light or other high speed particles pass through adn return back to earth. This will tell us more about the effects of various properties at distances where we might even begin to consider the variances that can occur to observations at cosmic distances.
the ‘truck’ is the central collective mass of the galaxy (which ‘varies’ location) the cars are the arms of solar systems ‘passing around the center’ which creates easier path to move because of its ‘clearing out’ the effect of spacetime which works to hold what would be larger masses in place. maybe a closer look at reasonable set of colliding galaxies would show some demonstrable function of such lack or proof the effect, as well confirm the above articles points.
— which creates easier path to move because of its ‘clearing out’ the effect of spacetime which works to hold what would be larger masses in place. —
I bet that you have no clue what “clearing out the effect of spacetime” even means.
i bet you can’t put forward an alternative theory that doesn’t involve unicorns.
You still have not explained what “clearing out the effect of spacetime” even means.
Ok i’m suppositioning that gravity and all other forces on particles exhibit differing properties while occupying a relatively ‘close’ around area of space when they approach certain collectives of mass. Think pulsar ‘event horizons’ or the surface of the sun how some ‘eddy’s’ spin faster than other areas, but around the area of galaxies and only on effect of mass / momentium in its relative location of over a particular period. Objects in the wake of speedily rotating galactic mass, will be able exhibit difffering properties than expected for they are in ‘fast lanes’ of fabric of space and time around these trillions of light years in volume ‘masses’. Especially when considering were talking speeds 500 km/sec.
– I am suppositioning that gravity and all other forces on particles exhibit differing properties while occupying relatively ‘close’ to an area of space when they approach certain collectives of mass. —
And how much mass per square km are we talking here? What would the average distance be between 2 particles be?
You call 500 km/s relativistic? It is fast but not that fast.
from my amateur armchair we’d need to talk masses / energy in the order of magnitude of >1 ×10 ^42 kg near the 30% radius of mass and as for density.. the density of collective solar systems would be when they approach a half to a light year distant from one another… (unless there are Vogons, then the distance might be longer. 😉
http://messier.seds.org/xtra/ngc/n2976.html is possibly the definition of the smallest conditions for the effect to occur. though… its a big ass sky.
“Relativistic” effects are not always associated with high velocities. They can be associated with other edge-cases, like extremely high mass.
I think I see what you’re getting at, but I am not sure I agree. It has long been known that there is a certain amount of “drag” associated with large moving masses (see Tipler: “Rotating Cylinders and the Possibility of Global Causality Violation”) but I do not see that these masses are large enough to cause a distortion effect: the distances between them in galactic arms are too great.
Not to mention that the relativistic effects are in relation to each other; not necessarily to an outside observer. That would have to be taken into account.
http://en.wikipedia.org/wiki/Time_dilation for example…
Nice post :))
I managed to finally located the proof and the first observation of actual dark matter.. It can be found here:
Enjoy!
wow, whoda thunk galactic rotation curves would incite so many comments?
perhaps because it so clearly demonstrates the conundrum of dark matter?
so, matter on a galactic scale must have an ‘aggregate effect’ on it’s containing volume of space.
we probably are vastly underestimating the amount of non luminous matter AND the instantaneous effect of massive bodies on one another.
how much matter has to be added to the sum to make the equations fit the observed?
What “conundrum” would that be?
There isn’t any added matter to a sum, _it is not a place holder_ as some erroneously and confusingly claim. Cold dark matter is a particulate source of gravity which is cold (so relatively heavy) and can be observed by various means. Say, gravitational lenses.
It happens to predict structure formation on all scales when the observed amount is included in the detailed models.
The observed amount is on the order of ~ 4 times the matter we already knew about. This was unanticipated (yay!) but not a “conundrum”.
Quoting article..
You probably want to put on your skeptical goggles and set them to maximum for this one.
…
With skeptical goggles firmly in place, the following conclusions might be drawn from this finding:
…
• The math has been retro-fitted to match already observed data;
• The math just doesn’t work; or
• While the author’s interpretation of the data may be up for discussion, the math really does work.
//end quote
Honestly Steve.. Having a little chuckle.. All of the above can be said of the current Dark Matter hypothesis (except the math not working – but no correlation yet in nature).
We have a large number of scientists on this planet accepting the existence of phenomena (DM/DE) which DO NOT EXIST (well the computer formula which seems a close fit to observations does currently exists but no strong correlations to observational AND experimental data).
That is, other than anecdotal observations and shaky correlations, there is no definite observational evidence linking these phenomena to experimental or mathematical models
(and please don’t show me pretty pictures like the bullet cluster
without a serious paper going into some correlations with observational/experimental data.
The only one I have found correlation I have seen so far is here:
http://www.freeimagehosting.net/35522
DM/DE are currently numbers in a computer formula. That’s it. Same as Carati’s claims….
ps. My skeptical goggles are always on. I think current scientific understanding could advance faster if other mainstream scientists worldwide followed that thing called the scientific method where a hypothesis becomes a theory – and in
all fairness DM/DE is no more than a leading hypothesis (unless anyone here knows of some strong research papers linking observed phenomena with the posit of DM…
Also how about a little less peer pressure from some members when posters rightly point out scepticism based on complete lack of proof (that is complete lack of credible correlation to observations as yet).
pss. Sorry to keep beating the same drum but we skeptics stick to our drums and keep the goggles firmly in place (Until proven wrong.. which can happen… But at least we are following the scientific method not accepting until proven and accepted by the worldwide scientific community) 😉
Here’s one example of your typical DM science paper today discussing Bullet Cluster image –
http://www.astro.umd.edu/~ssm/papers/MNRASv383p417.pdf
Title: The collision velocity of the bullet cluster in conventional and modified
dynamics, Authors: G. W. Angus1 and S. S. McGaugh
Quoting a portion of the summary:
” We have constructed specific mass models for the bullet cluster in
both CDM and MOND.We integrate backwards from the observed
conditions to check whether…”
Not to nit pick but as fine and wonderful and helpful as it is to theorize to create predictions, when do we get out of the laboratory and into nature to observe such predictions??? Or do we need to blindly accept the phenomena will never be observable because it is Dark ??? So really modern science tells us the same as the religious scholars: Trust us because it is in the books and higher authorities know this to be the case… (Sounds a bit like dogma to me??)
To keep balance and fairness I have provided link to DM proponents. Here’s one from an opponent:
http://www.toriah.org/science/big-bang/proof-of-dark-matter.htm
Here’s the summary of Eric Lerner’s information:
//start quote
Douglas Clowe’s team at University of Arizona claimed on August 21, 2006 that they found dark matter in the Bullet Cluster. They even had a picture of it. The NASA Chandra X-Ray Center called it a “direct proof” of dark matter. The story received wide publicity in the media.
…
What this paper actually provides evidence for is something very different: that in the case of this particular pair of colliding clusters of galaxies, the greater part of the mass is spatially associated with the galaxies and not with the hot intracluster gas. This evidence is that gravitational-lensing measures of total mass outline the concentrations of galaxies, which are physically separate from the main hot gas concentrations.
How do Clowe et al get from what was actually indicated to what they claimed? Only though a big assumption, which is in no way supported by their data.
The major assumption is that all of the baryonic, ordinary, matter is in the form of hot plasma or bright stars in galaxies. The paper shows that the total amount of gravitating matter, as measured by gravitational lensing, does not correlate with the amount of hot plasma, as measured by x-rays. // end quote
AND
http://milesmathis.com/bullet.html
//start quote – excerpt //
Even the opposition has been deflated by this paper, and many or most MOND supporters have backtracked, trying to save face by presenting new papers that show a mixture of dark matter and modifications. This in itself is a sign of the times, since it proves that neither side is capable of close analysis. The Clowe paper is extremely weak, as I will show below, and the fact that anyone would be cowed by it is a very bad sign for physics.
//end quote//
AND finally.. Looky what we have here:
http://chandra.harvard.edu/photo/2006/1e0657/1e0657_xray_lens.jpg
//Stat Quote – Chandra site //
Most of the mass in the cluster is shown in blue, as measured by gravitational lensing, the distortion of background images by mass in the cluster. This mass is dominated by dark matter.
// End quote
Can you spot the sentence which is an unsupported assumption?? 60 points to Torbjorn if he spots the clause 😉
This is from the Chandra X-Ray observatory site – http://chandra.harvard.edu/photo/2006/1e0657/more.html
No worries – but in this case there are data/evidence (the observed velocities). What we need is plausible theory to account for them. I don’t think MOND has a leg to stand on in the face ongoing confirmations of general relativity.
I am perhaps solo member of the density waves might explain spiral galaxy rotation curves fan club, but still think the lensing/cluster collision data are compelling evidence of invisible matter/mass.
There isn’t any added matter to a sum, there isn’t any numbers in a computer formula, _it is not a place holder_ as some erroneously and confusingly claim. Cold dark matter is a particulate source of gravity which is cold (so relatively heavy) and can be observed by various means. Say, gravitational lenses.
It happens to predict structure formation on all scales when the observed amount is included in the detailed models.
Wow again. Please don’t misunderstand: I am not claiming that a theory of Dark Matter is necessarily incorrect.
But characterizing gravitational lensing as “direct observation”??? You are going to have to explain that to me!
We ALREADY knew that a gravity-like effect is occurring. Seeing further evidence of that same gravity-like effect is not “direct observation” of a mass that may or may not be causing it, any more than the ORIGINAL observation of a gravity-like effect constitutes “direct observation”.
I am really starting to question your interpretations.
Don’t even want to interject in the main discussion at hand, but felt compelled to point out that math doesn’t much work yet on anything much passed NP complexity except in very general terms. I’d daresay math doesn’t work on most problems.
There is some really interesting stuff there!! Thanks for the links 🙂
Hi Jlinley,
A pleasure. Also refreshing to see other critical thinkers rounding the wagons. We need more physicists and people with critical thinking to question the mainstream tennant of DM being advanced as in my opinion it has become a weed in the garden which is displacing other theories when it has no right to (in terms of not having been proven yet definitively but being parroted by mainstream press as though it were)..
Also I recommend viewing the wikipedia page on
Dynamic equilibrium and
Radiative equilibrium
If these actual physically proven physics theorems were applied to a white hole singularity being torn apart by a (non) zero-point vacuum, then everything flows from there (pun intended).
It seems as though Einstein bundled together a packaged theory which goes along way towards explaining inflation/expansion by use of vacuum negative repulsion in dynamic equillibrium with matter/energy.
It’s a sign of the times that this body of work has been neglected for what is in my opinion an increasingly untenable hyposthesis (DM) in terms of having no real application in physics other than a neat computer model.
Best,
Wezley
Subject: [universetoday] Re: Astronomy Without A Telescope – Could Dark Matter Not Matter?
Hi Jlinley,
A pleasure. Also refreshing to see other critical thinkers rounding the wagons. We need more physicists and people with critical thinking to question the mainstream tennant of DM being advanced as
in my opinion it has become a weed in the garden which is displacing other theories when it has no right to (in terms of not having been proven yet definitively but being parroted by mainstream press as though it were)..
Also I recommend viewing the wikipedia page on
Dynamic equilibrium and
Radiative equilibrium
If these actual physically proven physics theorems were applied to a white hole singularity being torn apart by a (non) zero-point vacuum, then everything flows from there (pun intended).
It seems as though Einstein bundled together a packaged theory which goes along way towards explaining inflation/expansion by use of vacuum negative repulsion in dynamic equillibrium with matter/energy.
It’s a sign of the times that this body of work has been neglected for what is in my opinion an increasingly untenable hyposthesis (DM) in terms of having no real application in physics other than a neat computer model.
Best,
Wezley
Hi Wezley,
Thank you this is totally cool! I wasn’t aware of all these thought experiments into atemporality – I’m so glad you’ve introduced me to them as I thought I may have been going mad to think that time isn’t really a necessary quality of the universe 🙂 this really explains the constancy of the speed of light along with all Einstein’s postulates of SR and GR. It is simply how time, the process of motion, is measured and conceived by humans (with memory/clocks/sundials etc), or any ‘product’ WITHIN the system in question (the universe) in different regions of space, and the way clockwork as an actual mechanism progresses at a different …’rate’?! (there are no words for speed without the concept of time!) for objects at high speeds or near high gravity, which is contrary to intuition.
I think there is something about Einstein’s space-time, or the Lorentz relativistic ‘Ether’, which Einstein could not have possibly known at the time, before newly discovered particles, the advent of modern quantum physics and observed phenomena of galaxy formation invoking DM, which is just not descriptive enough to explain these observations. In the realisation of where gravity originates, that is possibly to say, how exactly matter does curve space-time, we will be able to find out whether or not this model of gravity speaks for itself…and all DM – AND possibly Dark Energy too!
I suppose all we want is to know how and why?! We just need to keep going despite any hot-headed opposition… I would like just a few physicists to keep going down the DM road, in case of the slim chance that it IS there, but the amount of ignorance in this community completely baffles me!
Best wishes!
Jethro
The wikipedia page on Dynamic Equilibrium was edited recently and has removed all link to Einstein et al… Grrrrr!!!
So here is where the correct trail can be found:
http://en.wikipedia.org/wiki/Brownian_motion
http://www.chronos.msu.ru/discussions/sorli_dynamic.html
(from this papers references)
References:
[1] Einstein A., Relativity: The Special and General Theory (1920), page 155
http://www.bartleby.com/173/
[2] Yourgrau P. (2006) A World Without Time: The Forgotten Legacy of Gödel And Einstein
[3] Sorli A., Sorli K. (2005) From Space-time to A-Temporal Physical Space,
Frontier Perspectives, Vol. 14, Num. 1.
[4] Fiscaletti D., Sorli A. (2005). Toward an a-temporal interpretation of
quantum potential. Frontier Perspectives, Vol. 14, Num. 2.
[5] Sorli A., Sorli I. (2005). A-Temporal Gravitation And Hypothetical Gravitational waves, Electronic Journal of Theoretical Physics, Vol 2, Num 5
[6] Loinger A. The gravitational waves are fictitious entities – II
http://arxiv.org/vc/astro-ph/papers/9904/9904207v1.pdf
[7] Goss. W.M. (2003). Sagittarius A* as an AGN
http://adsabs.harvard.edu/abs/2003ASPC..300..123G
There appears to be the usual confusion about gravity here. So I thought it was time to give my brief lecture on gravity and dark matter. The role of dark matter in galactic motion is not hard to see, and it only takes Newtonian mechanics to understand things.
We start with Newton’s second law of motion, force equals mass times acceleration (F = ma), with the force being Newton’s law of gravity for the force between two masses M and m F = GMm/r^2. We consider the large mass as a distribution of matter in a spherical region with volume V = (4?/3)r^3 and where the mass has a density ? so that M = ?V. So we replace M with that and get
F = G ?Vm/r^2 = (4?G?m/3)r.
This is a force which increases with radial distance. This is different from the radial 1/r^2 force we are familiar with for two bodies. We then equate the force with the mass times acceleration ma = md^r/dt^2, to use a bit of calculus. For those familiar with differential equations and some physics recognize this means the motion of a star in a galactic halo with constant spherical distribution of mass is equivalent to the motion of a mass on a spring. If this were the sole determinant of the motion of stars in a galaxy then the galaxy would rotate much as a solid disk. This “101 model” of dark matter then says the motion is the dynamics of a 2-dimensional spring system and if the motion is more or less circular (not elliptical) then a galaxy will rotate as if it were a solid disk.
However, of course there are other masses, such as stars and they tend to be clumped near the center of the galaxy. So for the motion of a star we consider the matter which is within the orbital radius, call that mass m’ and use the straight up Newtonian gravity law. The amount of luminous mass inside an orbital sphere depends on that radius m’ = m’(r). We then combine these two to get
a = dv/dt = GMm(r)/r^2 + (4?G?m/3)r.
I just threw this into Mathcad with m’(r) =m_0r and got a curve not too different from the velocity distribution illustrated here.
LC
Is it possible our models of gravity are incorrect? They are based on observation and assumptions. What if all matter does exhibit the same gravitational force? We have assumed certain things about the the cores of stars and our planets that may be incorrect.
Look at our assumption that nothing is faster than light. Why did we assume that nothing is faster than light? Because we had not observed anything faster.
It has not been assumed that nothing can move faster than light.
It all started with the observation that light seems to always move in the same speed (in a vacuum). this made absolutely no sense whatsoever until Albert Einstein showed that this can easily be explained by a transformation of 4 units (3d-velocity and time) called the Lorentz-transform. The odd thing about that transform is that it disallows travelling faster than the speed of light. But it is the only physicly explainable way to explain the constancy of the speed of light. It also gives a huger number of other observable and confirmable effects.
In order to change this, all you need to do is to demonstrate that light does not move in a constant speed (again, in a vacuum) and the job is done. This would disprove the Lorentz-transform.
Higher dimensional physics might change this, perhaps there are more variables to this after all, but none of that is yet supported (I am eagerly awaiting the end results from neutrino travels).
Actually, Occam’s (or “Ockham’s”) Razor would seem to favor Carati’s interpretation. After all, postulating that 80% of the Universe is composed of some kind of mysterious mass that does not otherwise interact with our reality is what is the more outrageous claim. I daresay you favor that interpretation merely because it is more familiar. Hardly a good way to measure scientific veracity.
What was unmentioned here is that Carati’s calculations would tend to eliminate any need for “dark energy”, too. Which, if anything, makes his idea that much more plausible.
But only if that explanation can explain more than DM. And as we are able to read above and elsewhere, it cannot. Therefore, Occam’s razor doesn’t count.
Actually, that’s not so. But we have conflation of several separate issues here.
First, William of Ockham’s rule of thumb dealt with explanations for the same phenomenon, and it presumes they are roughly equally plausible explanations, except for the “multiplication of entities”. It does not presume that one explains “more” than the other at all. But if we start from a presumption that the explanations are roughly equally “reasonable”, then Carati’s postulate is the clear winner, from the Razor’s perspective.
But as for that latter point, I am not so sure I agree. Evidence for dark matter and dark energy both has remained tenuous at best. Despite some clues that the concepts might be shown to be valid some time soon, that is all we have: hints: The fact is that so far they have not been.
I agree with your last paragraph.
On the other hand, this reminds me of the situation of the neutrino. It was theoretically invented around 1932 by Dirac (IIRC) to “save” energy conservation which seemed to be violated by the beta decay. It was eventually found in the late 1950.
The same holds (at the moment) for dark matter. We have some hints (very good hints from my POV), but a direct measurement is difficult, because it seems to be only interacting gravitationally. I can imagine such particles (which doesn’t mean that they have to be real, of course). It will be very difficult to detect them, naturally, but maybe we will succeed — or not.
The article finding is real and it actually supports the four hundreds years old de Duillier-LeSage theory, which is AWT compliant, BTW. Believe it or not, this theory is real, working well and it’s actually the only physical theory, which can explain the inverse square law on which Newton’s law and general relativity are based (the general relativity just borrowed the Newtons law into Einstein’s equation as it is, which means, even GR is actually Newton law dependent, not vice-versa as the mainstream propaganda is claiming…).
Anyway, in the Duillier-LeSage model the gravity is the effect of tachyon shielding with observable matter. These tachyons are essentially gravitational waves (Mr. de Duillier called them ultramundanne particles, which brings the multiverse concept on mind – a well 460 years before string theory!). And the dark matter is simply result of the shielding of these tachyons with all distant stars in the whole observable Universe. So it’s sorta shielding of shielding, which explains some antigravity aspects of dark matter. At the center of galaxy the distant stars are already shielded with stars at the perimeter of galaxy, so that their shielding of tachyons cannot apply there. Which explains, why the dark matter doesn’t violate Kepler’s law at the center of galaxy.
It means, if the Nicolas Fatio de Duillier would be more clever, he could derive the existence of dark matter just with using of his own insights. Which unfortunately didn’t happened (he couldn’t observe it anyway with the contemporary telescopes). Anyway, you can consider it as an independent confirmation of both de Duillier-LeSage theory, both the confirmation of both Carati’s derivation, both the observations of rotational curves of stars inside of galaxies choosen. I’ll can still draw some picture of this model – but I hope, this principle is clear enough for all of you.
The Earth is actually flat too.
Well I think its healthy discussion regardless of whether Carati is right.
Dark Matter is a theory, one which is very useful for explaining the observations of the motion of stars, but is missing one very important thing: We don’t know what the &#&*$(#$& Dark Matter is!!!!
“Although dark matter is the most popular theory to explain the various astronomical observations of galaxies and galaxy clusters, there has been no direct observational evidence of dark matter” – Wikipedia.
So that doesn’t mean Dark Matter theory is wrong at all. But one would hope, that if there is this massive amount of dark matter all around every galaxy, then we ought to be able to figure out what it is. Until we do, challenges like this will continue to appear.
@Steve You should threaten to excommunicate him – I hear that has a positive effect on keeping scientists in line with the status quo.
Ha!! Excellent.
DM is a theory based on the the failure to match our theories with observation. It was not discovered like normal scientific theories. what happened was that our theories said: x+y=z but observations show x+y=zA.
therefore we are ‘missing’ a thing called A. only time will tell if A is DM or A is a discrepancy in our calculations, or if we are missing another function, or even possibly have yet to discover a force or 2. until then, DM is hardly a theory but rather a convenient piece that makes our puzzle fit together nicely.
we are hardly close to understanding the universe so remain open to new theories. especially if the math in it is sound. after all, what else do we have to rely on but our mathematical and scientific tools? all else is just conjecture
DM is a much stronger theory than you give it credit for here. It is most definitely a theory and like many theories was created to explain a set of observations. It is well accepted for good reasons.
I too was somewhat skeptical of DM and felt much like you do, but after reading about some of the experiments that confirm it, I’m much more on board as is the majority of the scientific community. The Gravitational Lensing experiments/observations in particular are quite compelling.
So sure alternate theories are always welcome (if they are well thought out), however, they would have to be able to explain all the observations (like gravitational lensing). Of course I would love to know what DM actually is (what kind of matter is it). And of course it would be great to have more direct evidence (actually finding that matter).
I do not discount DM at all. My reply was more in support for this article and it’s findings.
The LHC is about to announce they may have found a 125 GeV Higgs which will mean the Standard Model will need to be fixed…maybe even implying supersymmetry.
The universe is filled with many more mysteries. DM has made physicists lazy and closed minded. We have yet to discover all the tools necessary for us to even begin claiming something undetectable (like DM) as the truth.
What is the REALLY extraordinary conclusion we get from this article is the idea of physisits for “a close fit”!!!
I quote: “Carati’s claim is that the math apparently deliver galactic rotation curves that closely fit the observed values of at least four known galaxies. Indeed, the math delivers an extraordinarily close fit.”
Where you people see the “close fit” ?? I am not a physisist but I can read a graph… I can accept that for the the first 5-10 kpc the experimental line and the theoretical one do have a close fit… but further down they go light years apart…
And that goes for both the DM model and the Carati’s one…
And you know what is even more amuzing? people in the comments area fighting about the two models… LOL!
@George P. Umm, don’t you see those little squares sitting right on the theoretical line?
Another armchair observation here…. Given the number of dimensions proposed by most current theories, we know that many of them are wrapped up at the microscopic level. However, given our inability to explain the large-scale structure of the universe, there may be one or more hidden at the macroscopic level, too. Our current indications that space doesn’t seem to be curved may not even be testing the right things.
So it could be that the relevant objects (things asserting what we regard as gravitational influence upon one another) are really “closer” than they appear to be on one level or another. While this might explain the galactic rotation conundrum, I don’t know how applicable it is to gravitational lensing observations, but I’m just throwing the idea out there. Until we pin down where all of the other dimensions are, I don’t know if it’s safe to assume that they’re all microscopic. Of course, they may all be microscopic and still exhibit macroscopic effects, possibly many more than we imagine, but I guess that remains to be seen.
Why would you start off your article with “You probably want to put on your skeptical goggles and set them to maximum for this one”? It makes me feel like you didn’t need to write the article at all if you don’t want to give your point a chance.
I proposed a new way of thinking.
http://www.geocities.jp/imyfujita/galaxy/galaxy01.html
Two dimentional space needs no dark matter for the flat rotation curve of the galaxy.
Iori Fujita
The obvious problem with that is that space is 3D.
I’ve had look at this, a brief one though. It is very interesting.
One thing I wonder which I would like to point out about the NGC 891 galaxy, where you mention that the dust could be dark matter… Dark matter is so called because it supposedly does not interact with electromagnetic radiation at all, I wonder if this is a translation problem or typing mistake??? In the same paragraph you mention that the condensed gravity field pushes light away. This doesn’t really comply with current physics! Could you expand on what you mean?
Your view on the structure of black holes is remarkably similar to mine – the current, most widely accepted idea of jets being born from super hot plasma are surely inconceivable, as matter at these points (around the poles) of the black hole should certainly have less energy (most obviously less kinetic energy), it should fall in to the black hole more easily, and of course in this current model there would be a higher gravitational field at the poles (under the same process as gravity darkening, which you had mentioned).
Good work!
so, we can either believe the preexisting hypothesis of dark matter, which is basically saying “well, we don’t have ANY bloody idea what’s going on, so we’re gonna add some invisible and hard to detect stuff to make the theories fit the observation”
OR
we can believe this guy with his clever mathematics, that actually eliminates the need for the ghost that is dark matter. I personally do not believe in ghosts.
Could this mystery of stellar motion in galaxies be so elusive because Science is viewing it through a strictly material lens (naturally). Therefore, Science insists(?) there MUST BE a material explanation (and there may very well be). What else would explain the outer stellar motions measured in galaxy-rims, or the dramatic gravitational lensing-effect of huge clusters – the inexplicable “weight of mass” behind the visible concentration of matter, the bending of light passing through its complex, or “lensed” around its vast enveloping halo(?).
To risk an unwelcome view, could it be an invisible FORCE, one that upholds or maintains the great star systems in spiral form and galactic shape? A sustaining power having physical effects around the enormous Island Universe assemblages – manifestations on Matter (within) and Energy (passing by them), but undetectable otherwise – not directly observable beyond its powerful affects (so far)?
There is “Dark Energy” : the expansion, acceleration of Space itself (if I understand). Is it an opposing agency to “Dark Matter” (poorly informed question, perhaps): that which reigns-in outer galaxy-disk star-fields, or influences passing “wavepaticles”(?) in space-time?
Could it be that the two “Dark” agencies are related (apart from their mystery element). One works outward from within, another works inward from without. (If I am not badly inverted!)
In the Microcosmos, the two Nuclear Forces, the strong and the weak, come to mind: they perfectly work together, so we exist in an ordered Cosmos. Are the two great “Dark” agencies separate and exclusive? Or are they complementary – working in perfect harmony in the Macrocosmos? Dual Forces working together in both the Atomic and Cosmic frontiers of our Universe – the morning study of which may be affording profoundly insightful reflections of our existence, from both ends of physical creation, which Science has only now begun to glimpse on the far horizon of its upward journey to a mountain-summit of vision (and astronomical observation).
What would the Universe be like, if there was no no spreading expansionary force, and outer stars of a system were not held fast within, but sprayed off into the night (from rotating, dissipating galaxies void of “Dark Matter”)? What would space be like without the vast stretches of time’s separating distance? ….
This interesting paragraph may be off-page, but seemed somehow in-line:
“One explanation for dark energy is that it is a property of space. Albert Einstein was the first person to realize that empty space is not nothing. Space has amazing properties, many of which are just beginning to be understood. The first property that Einstein discovered is that it is possible for more space to come into existence[?!]. Then one version of Einstein’s gravity theory, the version that contains a cosmological constant, makes a second prediction: ’empty space’ can possess its own energy. Because this energy is a property of space itself, it would not be diluted as space expands. As more space comes into existence, more of this energy-of-space would appear. As a result, this form of energy would cause the Universe to expand faster and faster. Unfortunately, no one understands why the cosmological constant should even be there, much less why it would have exactly the right value to cause the observed acceleration of the Universe.” — ( http://science.nasa.gov/astrophysics/focus-areas/what-is-dark-energy/ )
Well, the author did say “All comments welcome.”