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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.
faster than light neutrino measurements?
revolutionary-yet-pseudo-sciency sources of energy?
and now dark matter challenges?
coincidence or what?
https://www.accountkiller.com/removal-requested
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.
Well, THIS religious nutbar subscribes to the theory that gravity is really just the love felt between particles: just as absence makes the heart grow fonder, distance increases this attractive force, resulting in increased orbital velocities of stars.
Love makes the galaxy go 'round.
my, your, his/her/its, our, your, their
I'm, you're, he's/she's/it's, we're, you're, they're
Nope. A theory which explains away the dark matter MUST explain the observable effects of: http://en.wikipedia.org/wiki/Bullet_Cluster Then it should explain discrepancy between small and large galaxies.
Only after it passes these two tests it could be discussed seriously. Yet another "I can haz explain rotation curves!!!" theory is definitely not interesting.
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.
Seriously, is that the most you can add to the conversation is a cheap shot at religion?
It wasn't a shot at religion, it was a shot at religious fanaticism. There's a difference, and pretending otherwise is disingenuous at best.
I will agree that if such a claim is made it should be picked apart but can we just hold off the hostilities until it happens? For once?
Hostilities were opened a long time ago. Your objection makes as much sense as saying to the captain of a US Navy ship, "I agree that if that Japanese ship over there shoots at us, we should blow them out of the water, but can we just hold off the hostilities until in happens?" in 1943.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Translation: "I'm not bright enough to think about orbital dynamics, so I'll just try to start an offtopic religion-bashing troll thread instead."
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.
Just show the math and how it correctly models modern astronomical data.
I'll give you a hint, it doesn't even come close.
If someone is passing you on the right, you are an asshole for driving in the wrong lane.
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.
False. So completely and entirely false that I really can't see you being anything other than a troll, but on the theory that sufficiently advanced ignorance is indistinguishable from malice, I'll point out what several others have already done above: the Bullet Cluster, various details of the CMB, and at various aspects of large-scale structure in galaxy clusters, up to and including the closure of the universe itself, are all evidence for Dark Matter of various kinds.
So all you've done here is declare, "I am completely ignorant of almost all of observational cosmology and THIS is my opinion on Dark Matter..."
After reading the first half of that sentence no one who knows anything about Dark Matter is going to be the least bit interested in what you have to say in the second half.
Blasphemy is a human right. Blasphemophobia kills.
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
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.
Finally the long awaited proof that Ostriches are the work of the devil!
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)