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Scientists say dark matter doesn't exist

Abdul Alhazred

Philosopher
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That's a relief! Something about not multiplying entities.

Scientists say dark matter doesn't exist (MSNBC)

Two Canadian astronomers think there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn't exist.

Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies — stars, gas and dust — is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.

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Or maybe not.

...

Douglas Clowe, the lead astronomer of the team that linked the Bullet Cluster observations with dark matter (and now at Ohio University), says he still stands by his original claim.

"As far as we're concerned, [Moffat] hasn't done anything that makes us retract our earlier statement that the Bullet Cluster shows us that we have to have dark matter," Clowe said. "We're still open to modifying gravity to reduce the amount of dark matter, but we're pretty sure that you have to have most of the mass of the universe still in some form of dark matter."
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Any real physicists out there who can explain this better than MSNBC?

Thank you.
 
Dark matter was invoked to explain how galaxies stick together. The visible matter alone in galaxies — stars, gas and dust — is nowhere near enough to hold them together, so scientists reasoned there must be something invisible that exerts gravity and is central to all galaxies.
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This is not quite true, or it's not the whole story. Dark matter was first proposed because galaxies weren't rotating (stars weren't orbiting) the way they should if you took into account the mass of every visible object in that galaxy. In fact, they rotated as though most of the mass wasn't even in that galaxy itself, but scattered around nearby space. The problem was, we couldn't see anything there (even diffuse clouds of gas would have shown some spectral response), so they dubbed it 'Dark Matter'.

It also happens to be a convenient way to account for 'how did galaxies clump together. And it works well for that.

Some people don't like the idea of there being a whole bunch of things that we can't detect except through gravity. They'd rather alter how gravity works to account for the galaxy rotation problem.

The only problem is they can't come up with a mathematical model of that change in gravity that manages to fit the available data for galaxy rotation and galaxy clumping. The 'extra mass that we can't see' (Dark Mater) model does manage to fit most data, though there are a few possible anomalies even then.

Basically, "Dark Matter" isn't a specific, understood thing, but just a name given to something we're just barely beginning to study. So newspapers will mess up any story about it most of teh time.
 
My favorite is when Star Trek's Voyager encountered a dark matter nebula emitting electromagnetic radiation. Hello, oxymoron.
 
Anyone who remembers my "Dark matter should win the MDC" claim a few months ago:

Yeah. I get it now. I was stupid.
 
GM2, nice. The Wikipedia article on galaxy rotation curvesWP is also pretty informative; MOND is discussed as well as TeVeS and MOG. Of particular note is the fact that not only does dark matter well explain galaxy groups, clusters, and superclusters, it also does a good job when it's added to simulations of the evolution of the universe. You get distributions that look like what we see, and you don't get that from any of the modified gravity theories; we'll see if Brownstein and Moffat manage to get that.

The "Pioneer Anomaly" has been thoroughly debunked, last I checked. However, it looks like there is still some legitimate question on the subject. The Planetary Society, which is generally fairly hard-headed, is funding a project to recover and analyze the data from the Pioneer probes; this is difficult because since the launches of Pioneer 10 and 11, we have gone from punch-card and punched-tape readers to USB thumb drives. Latest update was from August of this year.

Personally, I got to go with the majority on this one; dark matter is too good an explanation. But I'm not set on it. However, it's worth contemplating the fact that there are pictures of it.
 
If the same standards were expected of the "Dark Matter" and "String Theory" theorists as are expected of the 911 Twoofers, a lot of theoretical scientists and mathmaticians would be teaching first-year/freshman physical Science courses or taking up jobs in accounting or economics.

1) A lot of claims; where's the proof?
2) A lot of coincidental events, presented in convoluted and indecypherable terms.
3) A lot of "Straw-Man" substances involved to produce the final effects.

Okay, for the record, I have more faith in any degreed Scientist's best guess than I have in any Twoofer's "documentation." But in both cases, all I'm asking for is some kind of material proof -- a smoking gun, if you will. And by material proof; show me some dark matter, a superstring, or some White House / Pentagon documents that detail the alleged involvement of America's government in planning and executing the attack on 9-11-01.

Before anyone gets excited and angry that I have dared to compare Science with Woo, let me point out that when it comes to Dark Matter, String Theory, and 911 Conspiracy Theory, the material proof has been the same. That is; nothing.
 
Not at all.

Dark matter is a well-formed and very reasonable hypothesis. When we look at the rotation of galaxies, it doesn't match the gravity we would expect from the amount of matter we observe. If gravity works at galactic scales the same way it does in our solar system - and there is no reason to think otherwise - then something that we can't detect is generating gravity. Dark matter is the term we use for this, whatever it might be.

String theory, meanwhile, is a mathematical model (or a class of mathematical models) of the way the universe works at small scales. It is not yet a testable hypothesis, so it would probably be better if it wasn't called "string theory", but the people working on it do understand the difference.
 
Fnord said:
But in both cases, all I'm asking for is some kind of material proof -- a smoking gun, if you will. And by material proof; show me some dark matter, a superstring, or some White House / Pentagon documents that detail the alleged involvement of America's government in planning and executing the attack on 9-11-01.

Before anyone gets excited and angry that I have dared to compare Science with Woo, let me point out that when it comes to Dark Matter, String Theory, and 911 Conspiracy Theory, the material proof has been the same. That is; nothing.
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The generally accepted sequence is: observe, hypothesize, test. Dark matter is a hypothesis for the observed galactic phenomena mentioned above; so is this new theory, just as many now-known particles in particle physics were originally hypothesized to fulfill missing mass/energy/spin/what-have-you conservations. Now, people will be developing tests which will establish one and disestablish the other (or possibly point out a third way), and making further observations of phenomena expected for one or the other theory; and thuswise the established theory will become a bit more real.

Be patient, young Fnord. :) Take the long view. Without the currently-proofless hypothesis, it is impossible to progress. In science there is no smoking gun, there is only another piece in the jigsaw puzzle of life. (Don't you love it when a metaphor comes together?)
 
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Fnord said:
Before anyone gets excited and angry that I have dared to compare Science with Woo, let me point out that when it comes to Dark Matter, String Theory, and 911 Conspiracy Theory, the material proof has been the same. That is; nothing.
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The ignorance is so strong, I'm left so speechless.

Read this article, and do your own research: http://en.wikipedia.org/wiki/Dark_matter

After you've researched dark matter as well as you can, then come back and tell us that the evidence is "nothing". And if you wish to continue to dismiss Dark Matter as non-existant, then please give a theoretical model that could account for the discrepancies that led to the theory of dark matter.

Thank you.
 
I’m not sure if Fnord is arguing on the same wavelength here. He literally wants to be 100% sure what the source (cause) of something is before he accepts it, no matter how much evidence of the signs (effects) are gathered. We don’t know the exact cause of gravity, but then again you can feel that every day so it’s easy to accept….. how about quantum physics? Signs of it aren't quite as common.

Perhaps he's hung up on the name since it could be just Dark Energy?
 
If he wants to be 100% sure, then he's still still demonstrating ignorance on the subject. No one is saying what Dark Matter is. We only have models that can most follow the evidence, and the best model that exists currently is the one that suggests that there may be "matter" out there that we cannot perceive. When I see a better model, I will take interest, but until then ranting about how we're not sure when no one is claiming that we're sure is pretty much a waste of time and energy.

And comparing this model with the claim that the U.S. Government killed several thousand of it's own citizens (even though all the evidence points in the other direction) is not only intentionally misleading and dishonest, but utterly disgusting in every way possible.
 
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Fnord said:
Before anyone gets excited and angry that I have dared to compare Science with Woo, let me point out that when it comes to Dark Matter, String Theory, and 911 Conspiracy Theory, the material proof has been the same. That is; nothing.
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First, as others have pointed out, you are wrong. There is a good deal of evidence suggesting that Dark Matter is, indeed real. Second, "Dark Matter" is simply the best explanation so far. Unlike the conspiracy theories you compare it with, should a better explanation present itself, it will be quickly abandoned.
 
Fnord said:
But in both cases, all I'm asking for is some kind of material proof -- a smoking gun, if you will. And by material proof; show me some dark matter, a superstring, or some White House / Pentagon documents that detail the alleged involvement of America's government in planning and executing the attack on 9-11-01.
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Take a look at the picture I linked in my post. It's currently my screen wallpaper. The dark parts are dark matter; they've mapped it by checking the distortion of galaxies behind it. The darkest parts are where the light from the galaxies behind it is the most distorted. What you're looking at is a gigantic tube-like structure, millions of light years across and hundreds of millions of light years long, with the open end pointing approximately at us. In the middle of it is a supercluster of galaxies.

That do it for you?
 
shadron said:
Be patient, young Fnord. :) Take the long view. Without the currently-proofless hypothesis, it is impossible to progress. In science there is no smoking gun, there is only another piece in the jigsaw puzzle of life. (Don't you love it when a metaphor comes together?)
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Yeah, I know ... an hypothesis is not necessarily factual, it just hasn't been demonstrated in a practical way, and that's just the nature of science.

But the Dark Matter / Superstring group is beginning to sound a lot like the twoofers -- a lot of talk about "theories" but nothing material to show for it (at least, it seems that way to me).

Oh, and thanx muchly for calling me "young!"
 
Fnord said:
Yeah, I know ... an hypothesis is not necessarily factual, it just hasn't been demonstrated in a practical way, and that's just the nature of science.

But the Dark Matter / Superstring group is beginning to sound a lot like the twoofers -- a lot of talk about "theories" but nothing material to show for it (at least, it seems that way to me).

Oh, and thanx muchly for calling me "young!"
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On Dark Matter: Well, obviously they don't seem to have material evidence if you ignore all the material evidence, but as has been pointed out to you already there is plenty of evidence. And I still don't hear you proposing an alternate theory that better explains the data.

That's how it differs from the conspiracy theories by the way, there isn't a better explanation for the data. No one is saying it's a perfect explanation, but :deadhorse you haven't given us a better one.
 
Fnord said:
Yeah, I know ... an hypothesis is not necessarily factual, it just hasn't been demonstrated in a practical way, and that's just the nature of science.

But the Dark Matter / Superstring group is beginning to sound a lot like the twoofers -- a lot of talk about "theories" but nothing material to show for it (at least, it seems that way to me).

Oh, and thanx muchly for calling me "young!"
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No. The whole point of dark matter is that it is an explanation for observations. The "something material to show for it" existed well before theories of dark matter were thought up to explain it. It is annoyingly common for people to do as you have done and group many different areas all into one lump and then say that since they haven't been proved they must be pseudoscience. There are several different groups, none of which are actually pseudoscience.

Dark energy/dark matter/inflation,etc.. These are all theories to explain observations. Observable matter doesn't seem to move how it should. This can be explained by the existence of more matter that we can't see. Very simple case of observation -> theory -> test. We are currently in the test stage. Similar for energy and inflation - they both try to explain observations.

String theory/M-theory/quantum loop/etc.. These are theories which try to explain our current theories in simpler or more elegant ways. It is not true that they have no evidence to support them - they have exactly the same amount of evidence as things like relativity. After all, it would be pretty stupid to come up with a theory that didn't explain things we have already observed. The problem is that there isn't any extra evidence to pick between them.

Imagine if relativity had been thought up a earlier so that no experiments could be done involving high velocities. It would produce exactly the same predictions as Newtonian mechanics. Would that make it pseudoscience? No. We wouldn't accept it as true, because it would give identical results as existing theory and it is generally easier to stick with the old one if the results are the same. But it would still work, and would be capable of being tested in the future. This is exactly where we are with string theory and others. They give the same results for things that we have observed, the challenge now is to make new observations to find out which theories are best.

If the worst comes to the worst, they will end up as simply interesting mathematical constructs. There is a huge amount of study into mathematical concpets that can't possibly exist, such as various different geometries, different numbers of dimensions, different kinds and shapes of universe and so on. Most of this is simply for the mathematics itself, although it often ends up providing useful insight or tools for use in the real world. Things like string theory are basically just a subset of these mathematical games which actually have a change of being true. For example, we know that the universe is not shaped like a teapot, so the description of this (yes, I have seen one) is simply a mathematical curiosity. We aren't sure that the universe isn't a multi-dimensional hypersphere, so this is considered theoretical physics rather than pure maths. At no point is any of it pseudoscience.
 
Irony said:
On Dark Matter: Well, obviously they don't seem to have material evidence if you ignore all the material evidence, but as has been pointed out to you already there is plenty of evidence. And I still don't hear you proposing an alternate theory that better explains the data.

That's how it differs from the conspiracy theories by the way, there isn't a better explanation for the data. No one is saying it's a perfect explanation, but you haven't given us a better one.
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What material evidence? Did I miss an exhibition of dark matter somewhere? Does the scientific equivalent of Wal*Mart carry spools of quantum superstrings?

By material evidence, I mean some thing that directly exhibits measurable properties, and not something that someone else believes in just because of a coincidental fitting of data. They may as well say "Goddidit."

I have no intention of giving a better theory, since I can not do so and I have not stated that I could. I am not a theoretical physicist or a mathematician, so my livelihood does not depend on convincing others that they should keep paying me to research something that I can only produce as a series of numbers on a blackboard.

In my profession (electrical engineering) proof is shown by material results, rather than by an incomprehensibly written paper in a relatively obscure scientific journal (I show them the equipment is working, rather than just write a note to a third party saying that it should). It just seems to me that saying that certain events are caused by something that can not be measured (it's invisible / theoretical / spiritual / Raelian, etc.) smacks of woo.

However, I have to admit that those scientists have greater knowledge than I do, and that they may actually be on to something. But, I'd also like to see some item or principle that I could exploit in my work. That's what I'm flogging the dead horse about.
 
Fnord said:
However, I have to admit that those scientists have greater knowledge than I do, and that they may actually be on to something. But, I'd also like to see some item or principle that I could exploit in my work.
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And I want to be king of Fnordia and wear a shiny hat.
 
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