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New Theory Challenges Need For Dark Matter
New submitter elsurexiste writes "An Italian Physicist came up with a strange way to explain anomalous galactic rotations without dark matter, instead relying on the gravitational effects of faraway matter. The article explains, '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.' As usual, these are extraordinary claims that divert from the consensus, so keep a healthy skepticism. The paper is available at the arXiv (PDF)."
I'm sorry, but "gravitational effects" won't sell popsci books. For the sake of our royalties, let's stick to dark matter.
Also there was that Galileo guy too.
(Must be all the espresso they're always drinking.)
There's no -1 for "I don't get it."
Does this explain the gravitational lensing in the Bullet Cluster?
This is the kind of theory that could have be viable prior to August 2006. When the gravity isn't pointing towards the baryonic matter, we have to postulate that there's some dark matter for the gravity to point to. Or, as Sean Carroll put it
The name "gravity" is prejudicial as it presupposes a connection between the alleged force and weight! "Intelligent Falling" is the preferred term.
ASCII stupid question, get a stupid ANSI
It's called Intelligent falling.
Disclaimer: I do experimental searches for dark matter for a living, so I may be biased in my judgement of these types of papers that crop up so often. There was a similar paper a few weeks ago from someone claiming that quantum vacuum polarization could account for dark matter PhysOrg link.
The issue with both of these explanations, is that they only address galactic rotation curves. Those are among the first and easiest to explain indications of the need for something like dark matter, but are not the strongest by a long shot. For instance, this guy's explanation can't explain things like the famous Bullet cluster , nor can they explain the evolution of structure formation or the spectrum of fluctuations in the cosmic microwave background which, in the field, are considered much stronger constraints.
The Cold Dark Matter (CDM) theory of cosmology fits all of the astrophysical measurements reasonably well, and has a nice tie-in to supersymmetric particle physics, which is one of the current leading theories. No one in the field will take any new theory seriously until it can reproduce ALL the phenomena at least as well as the current model (which of course is exactly how the scientific process is supposed to work!)
I don't understand why this theory is "implausible" and why the article is so dismissive of it. Dark Matter was created for the sole purpose of explaining the orbital momentum of stars. There is NO other evidence for it.
There is lot of other evidence for non-baryonic Dark Matter:
* Lack of MACHO gravitational lensing
* Existence of unexpected gravitational lensing in Bullet Cluster.
* CMBR measurements
* and more.
It isn't hard to modify equations to match the galaxy rotation curves, and if that was the only evidence for dark matter it wouldn't be so strongly favored.
Conventional leap of faith: this strange unseen matter exists and interacts gravitationally but somehow isn't available on Earth, cannot be created or observed or studied in a lab,
Unless supersymmetry is RP-conserving.
Electrical leap of faith: electrical processes explain the lack of mass through the electric force which is many orders of magnitude stronger than gravity and is more effective at long distances and is the only logical explanation for light-years-long jets of matter (Birkeland currents), can be observed in any laboratory with modest equipment and is known to scale both up and down, and through processes not yet understood there is enough charge separation in the Universe to provide the potential difference to cause these circuits to flow.
If you're willing to believe that far off galaxies have ridiculous amount of charge separation (something we have no theories or experimental evidence for), then believing that there are weakly interacting massive particles or other forms of dark matter can't be a stretch. Electromagnetism is strong (relatively), there would have to be something really trying to hard to convince the different charges to keep apart
I wonder how long it will be before science is forced to throw out dark matter and embrace electrical effects. Ten years? Twenty?
It's not a matter of time, it's a matter of evidence. If you can come up with a self-consistent theory that explains these electrical effects and have predictable effects that can be measured then you can have your moment in the sun.
-Bucky
Indeed, stupid scientists made a big complicated theory about forces proportional to masses and then after doing experiments and finding that things fall the same regardless of mass, they cover up their error by adding even more factors!
Occam's Razor requires us to believe that stuff all falls at the same rate because God decided that was the best rate.
Why this rate? When God created the world, He made the rate of fall exactly enough that we could walk on two legs, while all Lower creatures cannot because the Falling Speed is not tuned for them. If Falling was even slightly slower or faster, your feet would hit the ground out-of-step and would not be able to walk - co-incidence? No, proof that God made the world for Man.
A religious rant, condemning other theories as inadequate, antiquated, and conforming to orthodoxy. On the internet too. Wow, who would have anticipated that?
To be fair, using mathematical models on stuff we can see and measure seems a reasonable idea as opposed to inventing an invisible, incorporeal, magical material that we have no direct evidence even exists in order to compensate for our lack of understanding in how the Universe moves.
I just want to say- what little I do know, I've always disliked dark-matter. It always seemed to be a case of "we can't explain 'x' - so let's claim there is dark-matter and that will make our hypothesis match what we observe."
But you should realize that this technique has been used throughout the entire history of modern science, and its track record is actually quite good.
Back in the late 1700s, after the discovery of the planet Uranus, astronomers made careful calculations of its orbital elements and published a table the position of the planet in the sky over the years (and decades). As the years (and decades) wore on, they discovered a curious thing: the actual position of the planet was beginning to diverge from what had been predicted.
At this point, there were a few different explanations:
1) Perhaps the initial orbital elements were incorrect.
2) Perhaps our fundamental laws of gravity and motion were incorrect.
3) Perhaps there was a massive, as-yet-undetected eighth planet whose gravity was influencing the orbit of Uranus.
Most astronomers fell into the third camp; after all, the observations of Uranus's orbit had been made with considerable precision (for the time) and there was little reason to believe that the fundamental laws of physics would start to break down as you move further away from the sun. And so they made their calculations and narrowed down the location of this hypothetical planet to a fairly small window in the sky. After that, it was just a matter of pointing a telescope there and looking.
This is the story of the discovery of the planet Neptune.
Astronomers did not find this planet by accident. It was not discovered by a kid in the backyard with a streak of cosmic good luck. (In fact, many observers from antiquity had seen it, but had not realized what they were looking at.) They found it because they knew it had to be there.
Now, you might think that this comparison is a bit of a stretch. But it's just one example; there are countless more. Back in 1930, Wolfgang Pauli was studying beta decay in atomic nuclei. He realized that the process, as he was seeing it, could not possibly be happening unless there were (again, hypothetical) particles being emitted as a consequence. If there were not, then all sorts of fundamental principles of physics were being violated (e.g., conservation of matter / angular momentum / etc.)
This particle, eventually named the "neutrino", remained hypothetical and undetected for more than a quarter of a century until it was finally detected -- in 1956.
I could go on, but the point is that postulating the existence of something hypothetical in order to explain deviations between theory and observed results is part of the best traditions of natural science. It's not hand-waving or charlatanism. And it works more often than most people might think.
We're going down, in a spiral to the ground
They'll do anything, absolutely anything, invent any figment, totally divorce the mathematics from natural philosophy, propose strange exotic forms of matter never observed, and claim their existence is "proven" because they have a favorite explanation among multiple explanations not requiring strange exotic forms of matter.
The mysterious "Them"! A shadowy organization, nefarious and wicked.
They will do all of this, and more, to avoid admitting that "million degree gas" is conductive plasma and there is electricity in space and its attractive force is linear instead of following an inverse-square law, totally eliminating the need for any dark matter.
So Coulomb's Law is completely wrong just because PLASMA and ELECTRICITY IN SPAAAAAAAAAAACE!!! ? Why does nobody ever observe a linear attractive force for electric charge in the lab, under any conditions (including evacuated chambers and plasmas)?
And how does an incoherent shambling mess of a crackpot theory (the entire family of Electric/Plasma Universe wingnuttery) believed only by ignoramuses like yourself who don't even understand that like charges repel and opposite charges attract, a theory which has been disproven a thousand times over by real scientists doing real science, a theory which never gained any traction at all because it doesn't match how the universe observably works, solve anything at all?
Both require some kind of leap of faith. Conventional leap of faith: this strange unseen matter exists and interacts gravitationally but somehow isn't available on Earth, cannot be created or observed or studied in a lab, and is proposed to exist merely to fix a broken theory that never predicted its existence but can't get the expected results without it (Karl Popper spins in his grave...).
Nobody requires that you take a leap of faith and "believe" in dark matter. It's just the best explanation we've got right now, and last I checked, scientists are actively searching for both confirmation and disconfirmation of dark matter. If it were a faith industry, nobody would be doing either and that would be that.
Electrical leap of faith: electrical processes explain the lack of mass through the electric force which is many orders of magnitude stronger than gravity and is more effective at long distances
Trying to use the electric force to explain the observations which led to the proposal of dark matter is flatly stupid. Remember what I said just above about you not understanding that the electric force is only attractive for opposite charge? If you don't accept that, you are going against every observation of the electric force, ever. If you do accept that, then you've just disproven the electric universe theory, because the observed discrepancies from Newton's Law at cosmological scales are evidence of a consistently attractive force, like gravitation. If stars and planets and clusters and so forth were actually far enough from electrically neutral for the electric force to be a significant factor in their interactions with one another, you could never find a set of 3 objects which all attracted one another. Such objects are routinely found, therefore the electric universe theory is bunk.
So yeah, the EU theory requires a leap of faith: the kind of leap which requires you to ignore solid evidence which absolutely disconfirms the theory.
and is the only logical explanation for light-years-long jets of matter (Birkeland currents),
Calling LY-long jets of matter Birkeland currents is a perfect example of how EU true believers try to claim random phenomena as their own without rigorously linking them to EU theories. Birkeland's predictions related to the aurorae on Earth, not cosmological objects.
can be observed in any laboratory with modest equipment and is known to scale both up and down, and
Not sure about the summary, but the paper is extremely simple. I'll summarize it:
It is commonly assumed that galaxies are evenly distributed. This would mean that if you picked any galaxy at random, you could pick other galaxies whose gravitational pull totally balanced out the effect of the first one. So, overall, no distant galaxy would ever affect anything.
What is observed is that galaxies are NOT evenly distributed. There is, indeed, left-over gravitational pull. Provided the distribution of galaxies is self-similar (which is what they mean by "fractal", since "fractal" itself has no meaning here) AND a few other constraints are valid, THEN the left-over gravitational pull would be enough to explain the rotation of the stars and gasses within the galaxy. The author's analysis of the galaxies over a relatively nearby region of space suggests to him that the distribution is indeed self-similar.
(Summary off, analysis on)
Is this a new theory? As a replacement for Dark Matter, yes. In any other context, no. Shepherding moons/asteroids dominate our own solar system, creating a dynamic that would be utterly unstable without them. Shepherding galaxies and super-galaxies is a new one, but if the physics is observed in other systems then the physics must be considered sound. The only question I see here is whether the distribution of galaxies is indeed self-similar. If it isn't, the theory is wrong. If it is, then dark matter - as it is currently understood - must be wrong because you now have left-over gravity and you have to alter the dark matter theory to allow for it.
Doesn't the dark matter theory fit things well as it is? No it doesn't. Dwarf galaxies and globular clusters exhibit NONE of the signs assumed to indicate the presence of dark matter. Some don't have high-speed rotation at all. Dark matter theory cannot explain either of these and the usual answer is to say that dark matter "isn't uniform" without ever explaining why it should be missing only with certain classes of structure and not others. It's actually much easier to say that "excess" rotational velocity is a function of residual gravity and that where you have little residual gravity you have no excess rotational velocity. It is also entirely plausible to argue that "null points" are backwaters and that this explains why you get relatively few major galaxies appearing at such points but do get minor multi-stellar structures.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Are you daring to question existence of phlogiston, that glorious celestial substance that suffuses the luminous aether?
Pistols at dawn, sir.
DISCLAIMER: I am not a astrophysic, and I have the good sense to not to claim that the new theory looks like better (fits observations better) than dark matter. The scientific process will eventually sort it out (and not through an /. poll). This post is not about the theory but about the posts on it.
When Wegener postulated its theory, even if the underlying details were not fully understood, it was a scientific one because it answered to observation (size of continents, identical fossils found at different continents, etc.).
Fortunately, there was no internet then, because there would be a deluge of posts by uninformed people who didn't knew shit of what they were talking about, but felt that theory too "radical" and that they had to restore order (go read the GGP talking about "totally divorce the mathematics from natural philosophy").
The most funny things about those guys is that they would look at the abstract of a full scientific study and counter it with and abstract... "similar fossils? they have been spread by African swallows. Hey, that solves it, I am so sure that I won't ever check if this can be possible."
Nowadays, we have some amateurs who take several years of observations, heavy mathematical work and just threw out of their asses "I'd look at friction of intestellar gasses around the ejection plumes from black holes". Where is your data? Your correlation of the expected results with observations? Your predictions and/or experiments?If you have some of it, don't send it to me, publish the paper to help science, please.
Don't get my wrong, I am not annoyed by it. It could be annoying if those people were wasting someones time for this, but no scientific is going to come to /. searching for theories, so it is mostly harmless entertainment that brings a smile to my face :-)
The funny thing is that those nutjobs always leer in the same direction, opposing the "unnatural" posibilities. Are they afraid that the world is becoming too complicated? I feel there are too many camouflaged ludites out there.
And, finally, my goodbye present.
Why can't