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Dark Matter Exists

samzenpus posted about 8 years ago | from the not-just-ordinary-matter-anymore dept.

459

olclops writes "It's a big day for astrophysics. After much speculation, scientists now have conclusive proof of dark matter. This result doesn't rule out alternate gravity theories like MOND, but it does mean those theories will have to account for exotic forms of dark matter."

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Dark Matters (5, Informative)

ackthpt (218170) | about 8 years ago | (#15952458)

The announcement [slashdot.org] of the pending announcement [nasa.gov] regarding Dark Matter [wikipedia.org]

"This is the most energetic cosmic event, besides the Big Bang, which we know about," said team member Maxim Markevitch of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

I guess he's never heard of Zaphod Beeblebrox.

"A universe that's dominated by dark stuff seems preposterous, so we wanted to test whether there were any basic flaws in our thinking," said Doug Clowe of the University of Arizona at Tucson, and leader of the study. "These results are direct proof that dark matter exists."

Also a bit of info on physorg [physorg.com]

How does the Coalsack Nebula [seds.org] fit into this? It's dark and it's matter, right?

Re:Dark Matters (4, Funny)

Anonymous Coward | about 8 years ago | (#15952470)

Is it proof that dark matter exists that the link takes me to a blank page???

Re:Dark Matters (1)

gardyloo (512791) | about 8 years ago | (#15952487)

How does the Coalsack Nebula fit into this? It's dark and it's matter, right?

      "dark matter" I don't think it means what you think it means.

Re:Dark Matters (1)

ackthpt (218170) | about 8 years ago | (#15952767)

"dark matter" I don't think it means what you think it means

It's probably Pre-Dark Matter.

Re:Dark Matters (2, Insightful)

Anonymous Coward | about 8 years ago | (#15952507)

"A universe that's dominated by dark stuff seems preposterous"

But not as preposterous as the "Big Bang". Imagine all the matter of the universe compressed to the size of an electron. Well that is a fabulous explanation for observations. Any other ideas?

Re:Dark Matters (3, Informative)

cicatrix1 (123440) | about 8 years ago | (#15952668)

How's this: imagine that there is some being which created everything by magic. Did he create himself? Was he himself created? Sure it's also preposterous, but consider it as an alternative.

Blog First, Then Scientific Journals. (3, Insightful)

iamlucky13 (795185) | about 8 years ago | (#15952518)

Funny, I always figured the announcement of experimental confirmation of dark matter would first be published in a scientific journal or announced at a news conference...not on a blog shared by Mark, Claire, and Sean, whoever they may be.

* Note that I tried to go back and confirm the names and finish reading the story so I would have something intelligent to say, but apparently the user's CPU allottment only accounts for 20% of the server's total, suggesting that there may be another form of CPU cycles that don't interact with visitor's to the linked site. I think we should call these "dark CPU cycles."

Re:Blog First, Then Scientific Journals. (1)

Marxist Hacker 42 (638312) | about 8 years ago | (#15952545)

Ah well, serves them right- their server melted down from the slashdotting.

Re:Blog First, Then Scientific Journals. (4, Funny)

Ruff_ilb (769396) | about 8 years ago | (#15952688)

It didn't "Melt Down".

It underwent a resonance cascade reducing the server into its Dark-Matter counterpart.

Sheesh, get with the program here!

Re:Blog First, Then Scientific Journals. (4, Funny)

debilo (612116) | about 8 years ago | (#15952578)

Funny, I always figured the announcement of experimental confirmation of dark matter would first be published in a scientific journal or announced at a news conference...not on a blog shared by Mark, Claire, and Sean, whoever they may be.

I'm outraged -- are you really implying that we should take this proof of dark matter with a grain of salt, while there's this well-known Irish company that's using dark matter to produce free, clean and constant energy right now?

Re:Blog First, Then Scientific Journals. (0)

Anonymous Coward | about 8 years ago | (#15952592)

Excuse me sir, would you like to buy this fine bridge?

Re:Blog First, Then Scientific Journals. (1)

cicatrix1 (123440) | about 8 years ago | (#15952630)

Was that a coffee joke?

Re:Blog First, Then Scientific Journals. (1)

rtaylor (70602) | about 8 years ago | (#15952581)

It's a perceived trait only. Time within the CPU in the server stops every 1/5th of a second for a duration lasting 4/5ths of a second. A 20% quota represents the full calculating capacity of the machine.

Re:Blog First, Then Scientific Journals. (4, Informative)

wanerious (712877) | about 8 years ago | (#15952737)

Funny, I always figured the announcement of experimental confirmation of dark matter would first be published in a scientific journal or announced at a news conference...not on a blog shared by Mark, Claire, and Sean, whoever they may be.

They're physicists (I think Sean Carroll works in cosmology, formerly of the U. of Chicago, now at Cal Tech). It was announced, and the paper has been written. The blog, by the way, is really good.

Re:Blog First, Then Scientific Journals. (2, Funny)

mysticgoat (582871) | about 8 years ago | (#15952797)

Funny, I always figured the announcement of experimental confirmation of dark matter would first be published in a scientific journal

that thinking is SO twentieth century...

Re:Dark Matters (0)

Anonymous Coward | about 8 years ago | (#15952523)

"A universe that's dominated by dark stuff seems preposterous, so we wanted to test whether there were any basic flaws in our thinking," said Doug Clowe of the University of Arizona at Tucson, and leader of the study. "These results are direct proof that dark matter exists."

I don't get your quote - it seems contradictory.

Re:Dark Matters (4, Informative)

Surt (22457) | about 8 years ago | (#15952524)

In case your question is not meant to be humorous, the Coalsack Nebula is not 'dark' in the same sense as dark matter. It's conventional matter that is not well lit.

Re:Dark Matters (1, Interesting)

LiquidCoooled (634315) | about 8 years ago | (#15952599)

Thanks, where the Enlightening mod when you need one?

Though in practice, the dark matter nebula they claim to have found could simply be a much finer dust made up of former neutron star [umd.edu] particles?

Re:Dark Matters (5, Informative)

Surt (22457) | about 8 years ago | (#15952694)

I'm not an astrophysicist, so feel free to consider this only mildly informed:

What they claim to have found is a very hot galaxy undergoing gravitation not explainable by the conventionally visible matter.

All of the conventional matter in the area should be hot enough to be conventionally visible.

But since they can't see enough matter to account for the gravitation we have to conclude:

1) It's dark matter. That mysterious stuff that just doesn't interact like conventional matter, but does cause gravity.
2) It's conventional matter in some seriously surprising state that we don't understand, causing it not to be visible.

And their conclusion is that #1 is the more likely explanation. #2 seems unlikely because you would expect to observe this surprising state in the local galaxy or in experiments we perform in colliders.

Re:Dark Matters (5, Funny)

x2A (858210) | about 8 years ago | (#15952777)

"2) It's conventional matter in some seriously surprising state that we don't understand, causing it not to be visible"

What... like, being behind other matter? :-p

Re:Dark Matters (1)

Lord Ender (156273) | about 8 years ago | (#15952542)

Proof? I thought science was about skepticism. But "the results give us a high degree confidence in the accuracy of the dark matter theory" doesn't make headlines, I guess.

Re:Dark Matters (4, Insightful)

samkass (174571) | about 8 years ago | (#15952577)

Indeed, there is no such thing as "proof" in science. Merely observations that support a current theory. I guess "we observed phenomena consistent with a theory that claims dark matter's existence" even less headline-worthy.

Silly Musings..... (2, Interesting)

tempest69 (572798) | about 8 years ago | (#15952606)

I'm wondering how much "dark matter" is simply protons.. From what I remember from RadioIsotopes class unbound neutrons decay in about 15 minutes to a proton an neutron.. But I'm not sure what would happen to masses of stray protons in interstellar gas. The repulsion alone would prevent some coalesing activity, making it harder to form stars.. And they should be invisible, as there are no electrons to change energy states. So it should be perfectly transparent. But I dont have the the math to really figure out the system on that scale... Anybody want to set me straight?

Storm

Re:Silly Musings..... (5, Informative)

Xeriar (456730) | about 8 years ago | (#15952677)

There are very few free protons or free electrons, and no free neutrons (half-life of about 15 minutes before it turns into hydrogen) - nearly all interstellar matter is composed of hydrogen and helium. Beyond which, by your theory they would be generating an absolutely massive electromagnetic charge.

Beyond that, though, it's estimated that about half of baryonic matter is invisible for various reasons - thus, the Universe appears to be composed of 2% luminous baryonic matter, 2% invisible baryonic matter, 23% dark matter and 73% (and increasing) dark energy.

I'd like to post a mirror but... (4, Funny)

Enuratique (993250) | about 8 years ago | (#15952474)

...the server must have known of the impending slashdot effect and preemptively protected it's CPU from the impending meltdown

Full Paper (5, Informative)

Anonymous Coward | about 8 years ago | (#15952519)

The full paper can be found here. From the abstract: [harvard.edu]
We present new weak lensing observations of 1E0657558 (z = 0:296), a unique cluster merger, that enable a direct detection of dark matter, independent of assumptions regarding the nature of the gravitational force law. Due to the collision of two clusters, the dissipationless stellar component and the fluid-like X-ray emitting plasma are spatially segregated. By using both wide-field ground based images and HST/ACS images of the cluster cores, we create gravitational lensing maps which show that the gravitational potential does not trace the plasma distribution, the dominant baryonic mass component, but rather approximately traces the distribution of galaxies. An 8 sigma significance spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law, and thus proves that the majority of the matter in the system is unseen.

Oh, wow! (1)

PunkOfLinux (870955) | about 8 years ago | (#15952475)

Starship fuel! And... if dark matter exists... then something must exist to have created the dark matter... Onward, to Vergon 6!

Re:Oh, wow! (2, Funny)

slashbob22 (918040) | about 8 years ago | (#15952605)

Bring a heavy ship! Remember: each pound of weighs over 10,000 pounds.

Proof? (-1, Redundant)

no_opinion (148098) | about 8 years ago | (#15952483)

The only thing I see proof of here is a dark server...

I Doubt It (0)

Anonymous Coward | about 8 years ago | (#15952484)

Proof is a big word and Dark Matter is a very silly theory, I want it in the lab before I accept somthing THAT unlikely!

Re:I Doubt It (1)

exp(pi*sqrt(163)) (613870) | about 8 years ago | (#15952547)

What's silly about proposing that we can't see all of the matter in the universe?

Re:I Doubt It (5, Funny)

Twisted64 (837490) | about 8 years ago | (#15952763)

Clearly, this matter which refuses to reflect light in our visible spectrum has something to hide. Ergo, it is terrorism and must be quashed.

Dark matter and tech (1)

Lord_Dweomer (648696) | about 8 years ago | (#15952486)

So...now that we know it exists, we'll inevitably try to figure out how to harness it. I mean, its so plentiful right? Any logic-based theories as to what technologies might be developed as a result of this? I'm really curious what scientists will be able to do with this now that they have proof its real. Yes...I'm interested in the studies that will occur and what we'll learn about this, but i'm dying to see what they'll be able to make it DO...this is an entirely new form of matter here!

Re:Dark matter and tech (2, Interesting)

Vo0k (760020) | about 8 years ago | (#15952509)

It may be spread uniformly in the intergallactic space, meaning it's useless with density under a gram per cubic kilometer. Or it may form denser formations at distances that are useless. I mean, we're harnessing power of only one star out of a whole universe of them...

Re:Dark matter and tech (2)

ZombieWomble (893157) | about 8 years ago | (#15952534)

They claim proof that it's real, but they have no mention of proof of what it actually is. All this proves is that there is "something" there, and that it A) is not observable directly through our favourite tools (EM Emission) and B) It does exert a graviational force.

To draw any conclusions about the potential applications of this material is pretty much impossible until we actually work out what it is.

Re:Dark matter and tech (1)

venicebeach (702856) | about 8 years ago | (#15952591)

"They claim proof that it's real, but they have no mention of proof of what it actually is."

What kind of an answer would be satisfying there? It seems to me that we don't know what regular matter actually is.

Re:Dark matter and tech (0)

Anonymous Coward | about 8 years ago | (#15952800)

Regular matter, hell, we don't know what gravity is, but we do know there's something we can't see out there doing it.

I've always wondered about the old balls-on-a-rubber-sheet view of gravity... what if it's backwards, it's not that the ball is making the dimple in the sheet causing everything to roll towards it, what if the dimple was already there, and thats why the ball rolled to that point in the first place? If all of the matter just suddenly vanished, the gravity wells would remain, waiting for something new to fall in.

Re:Dark matter and tech (1)

x2A (858210) | about 8 years ago | (#15952819)

isn't matter just energy with gravity? We just don't understand 'how come'?

Re:Dark matter and tech (1)

ZombieWomble (893157) | about 8 years ago | (#15952843)

True, perhaps the use of "is" was a bit too emphatic, but the point remains - we still have pretty much no solid information on any properties other than the two I specified in my post.

This means that there are numerous possible explanations of the nature of dark matter - there are numerous potential explanations of how regular matter could account for this mass (brown dwarves and the like) not to mention countless theoretical forms of 'exotic' dark matter (that is, consisting of entirely new elementary particles) which it could be.

These different possible particle types all possess greatly differing properties, and so until we get a bit more information on these properties, we are effectively no closer to characterising this matter in any effective fashion, which was what I identifying what it "is".

Re:Dark matter and tech (3, Funny)

cryptoluddite (658517) | about 8 years ago | (#15952576)

I say we use it to build a dyson sphere around the entire universe. Then we can finally solve the question of whether the universe is expanding / contracting / balancing. The hard way.

Re:Dark matter and tech (1)

kfg (145172) | about 8 years ago | (#15952851)

Any logic-based theories as to what technologies might be developed as a result of this?

Dark technologies. Really, really dark technologies. Trust me, if you're a Jedi you won't like them.

KFG

Stargate? (3, Funny)

WVDominick (860381) | about 8 years ago | (#15952491)

How does this effect the Stargate program?

Re:Stargate? (2, Informative)

WilliamSChips (793741) | about 8 years ago | (#15952601)

We're one step closer to a working Zero Point Module

Re:Stargate? (1)

Capricous (847089) | about 8 years ago | (#15952662)

How does this effect the Stargate program?

Sorry, you just dreamed up the last 2 years of your life.
You didn't stand up to the military and you're not dating anyone.
But I have a Windows OS you can fix!

Re:Stargate? (1)

WilliamSChips (793741) | about 8 years ago | (#15952842)

I didn't know the Asurans posted on Slashdot...

Re:Stargate? (1)

JourneyExpertApe (906162) | about 8 years ago | (#15952670)

"How does this effect the Stargate program?"

Are you implying that it doesn't exist already? (Note: pay special attention to the word in italics ;)

Grammar Nazi Strikes Again (1, Offtopic)

Ruff_ilb (769396) | about 8 years ago | (#15952707)

the PP is correct, before anyone jumps off and gets on his case, as has happened before.

From Dictionary.com

Effect
tr.v. effected, effecting, effects

            1. To bring into existence.
            2. To produce as a result.
            3. To bring about. See Usage Note at affect1.

(e.g. "The Senator was afraid that the new policy would effect higher oil prices.")

Also, effect is often seen as a noun, meaning (among other things) a result. For example: "The Senator was afraid that the new policy would have detrimental effects on the oil industry."

On the other hand:

Affect
tr.v. affected, affecting, affects

            1. To have an influence on or effect a change in: Inflation affects the buying power of the dollar.
            2. To act on the emotions of; touch or move.
            3. To attack or infect, as a disease: Rheumatic fever can affect the heart.

(e.g. "The Senator was afraid that the new policy would adversely affect the oil prices, dragging them higher.")

Affect is rarely used as a noun, although it is much more commonly seen as a verb. Affect as a verb: "The man had a strange brand of body language that lent him an odd affect."

If you don't believe me:

Usage note from dictionary.com:

"Usage Note: Affect and effect have no senses in common. As a verb affect is most commonly used in the sense of "to influence" (how smoking affects health). Effect means "to bring about or execute": layoffs designed to effect savings. Thus the sentence These measures may affect savings could imply that the measures may reduce savings that have already been realized, whereas These measures may effect savings implies that the measures will cause new savings to come about."

Usage note from wikipedia.com:

"Do not confuse affect with effect. The former is used to convey the influence over existing ideas, emotions and entities; the latter indicates the manifestation of new or original ideas or entities. For example, "...new governing coalitions during these realigning periods have EFFECTED major changes in governmental institutions" indicates that major changes were made as a result of new governing coalitions, while "...new governing coalitions during these realigning periods have AFFECTED major changes in governmental institutions" indicates that before new governing coalitions, major changes were in place, and that the new governing coalitions had some influence over these existing changes."

Usage note from Write101.com:

"The easiest way to distinguish the two is to remember that affect is a verb (well, nearly always a verb) and effect is a noun ... well, nearly always! [...]
When affect is pronounced [uh FEKT] and accented on the final syllable, it's a verb meaning "to have an influence on."
eg Nothing they did, could affect my decision to go to the beach.
Occasionally, very occasionally, the word is used as a noun (it means a feeling or emotion, as distinguished from thought or action, or a strong feeling having active consequences) and the accent is on the first syllable [AFF ekt]. This is a term that is reserved for psychiatry and psychology:
eg In hysteria, the affect is sometimes entirely dissociated, sometimes transferred to another than the original idea.
Effect is most usually a noun and it means the result of some action or the power to produce a result. The noun is pronounced [uh FEKT] :
eg The effect of the bushfire was clearly visible.
eg The soothing music had an immediate effect on the wild beast.
This can also be a verb and it means to bring into existence, to produce a result (pronounced [ee FEKT]}"

Re:Stargate? (4, Funny)

LordEd (840443) | about 8 years ago | (#15952752)

Last time I checked, its still on my local channel 12 on at 6:00 pm. It has been completely unaffected by this discovery.

But check with your local TV listings, just in case.

Re:Stargate? (1)

WilliamSChips (793741) | about 8 years ago | (#15952822)

I assume you didn't hear this [gateworld.net] .

Re:Stargate? (1)

CosmeticLobotamy (155360) | about 8 years ago | (#15952845)

I just checked. The brooms are still in there.

More info from a server that's not on fire... (5, Informative)

mpathetiq (726625) | about 8 years ago | (#15952497)

Somehow I also think... (5, Funny)

Anonymous Coward | about 8 years ago | (#15952500)

It's a big day for astrophysics.

This Account Has Exceeded Its CPU Quota

I think it's going to be a big day for their webmasters as well.

Sweet! (5, Funny)

BigZaphod (12942) | about 8 years ago | (#15952503)

Now it's our turn to hide from the dark matter and wait for it to discover us! Come one everyone - pick a hiding spot and get to it! Hurry!

Fine - Dark Matter exists. Now tell me whether (0, Funny)

Anonymous Coward | about 8 years ago | (#15952839)

all this Dark Fiber [wikipedia.org] that they talk about really exists, 'cause I'm still stuck on dial-up :-(

and, presumably... (4, Funny)

Pike (52876) | about 8 years ago | (#15952526)

does this mean grey matter exists as well?

Re:and, presumably... (2, Funny)

JesseL (107722) | about 8 years ago | (#15952597)

It may exist, but there is very little observable evidence for it on this planet.

Re:and, presumably... (1)

dreamchaser (49529) | about 8 years ago | (#15952708)

Not on /.

Dark Matter Exists (0, Troll)

Anonymous Coward | about 8 years ago | (#15952536)

It's in space, though. And according to all of our data, it is also gay. Please see our website for more information: http://www.gnaa.us/ [www.gnaa.us]

Water (0)

netglen (253539) | about 8 years ago | (#15952541)

Dark water, flush twice.

It has to be said (1)

WhatDoIKnow (962719) | about 8 years ago | (#15952544)

I, for one, welcome our...

:wq

Re:It has to be said (1)

Shadyman (939863) | about 8 years ago | (#15952587)

No, sorry, I think you meant... :q!

Re:It has to be said (1)

jpardey (569633) | about 8 years ago | (#15952784)

...redundant overlords?

i don't believe it (4, Funny)

User 956 (568564) | about 8 years ago | (#15952551)

After much speculation, scientists now have conclusive proof of dark matter.

Well, their proof is based on the detection of gravity and gravitational fields. Every real American knows that it's not "gravity", but "intelligent falling". Gravity is a myth invented by foreign scientists to make all Americans seem overweight.

The new result, in a nutshell (5, Informative)

StupendousMan (69768) | about 8 years ago | (#15952563)

Astronomers observed a distant cluster of galaxies in optical light, with ordinary telescopes, and in X-ray light, with a telescope in space. This is an unusual cluster of galaxies, since there is clear evidence that one small group of galaxies are "interlopers:" members of a smaller cluster which fell into a larger one some time ago. Members of this interloping group are all bunched together at one side of the main cluster.

The visible light image shows the galaxies within the cluster. It also shows, much fainter and much smaller, a very large number of BACKGROUND galaxies -- these are objects way, way farther away than the big cluster. As the light from these background galaxies passes through the big cluster, it is bent very slightly by the gravitational field of the cluster. This gravitational lensing distorts the shapes of the faint, little background galaxies just a bit, but with care, we can measure the effect. We learn from the lensing where the matter is in the cluster: that is, we can figure out where the stuff which produces gravitational effects is distributed. That's part one: a map of the matter within the cluster, based on gravitional lensing.

The X-ray image shows emission from hot gas within the cluster. We have known for several decades now that large clusters of galaxies are immersed in giant clouds of very hot gas, at temperatures of millions of degrees. The gas emits copious amounts of X-rays. In most clusters, the amount of this hot gas -- its total mass -- is much larger than the amount of mass we can see in stars. That is, counting the stars in the galaxies suggests a total amount of mass-in-stars M, but computing the amount of hot gas necessary to emit all the observed X-rays yields a mass-in-hot-gas of around 10*M, ten times as much.

On the other hand, the amount of mass derived from the gravitational lensing of background galaxies is about 10 times larger still, or about 100*M. The stuff which produces the gravitational lensing does not emit visible light, nor X-ray light, nor, as far as we can tell, any electromagnetic radiation. Therefore, we call it "dark matter". It produces a gravitational force, but that's about all we know about it. (There are additional reasons for believing that this mysterious stuff is not made up of electrons, protons and neutrons, but that's another story).

This new result is interesting for this reason: the X-rays appear on one region of the cluster of galaxies, telling us that the bulk of the ordinary matter is RIGHT HERE. The map of total mass we can make from gravitational lensing appears in a different region of the cluster, telling us that the bulk of the dark matter is OVER THERE. It is very clear that the dark matter and ordinary matter are distributed in different places. This isn't too surprising, perhaps, if one small group of galaxies rammed into a big cluster -- the gas ram pressure might push on the ordinary hot gas in a different way than on the dark matter (which wouldn't feel any ram pressure at all, actually).

As Martin Hardcastle pointed out to me in a Google newsgroup a few days ago (thanks, Martin!), this is certainly not the first evidence for dark matter -- we have a number of examples in which gravitational forces are larger than the amount of visible matter would suggest -- but it is the first good case in which the distribution of the dark and ordinary matters are so clearly displaced.

Re:The new result, in a nutshell thanks (1)

cinnamon colbert (732724) | about 8 years ago | (#15952657)

i really good comment to 100 wiseass stupid comments - pretty goood for /.

Can you comment on whether the data support a candidate such as wimps, machos, etc ? (or am I betraying my ignorance with these acronyms

Re:The new result, in a nutshell thanks (2, Informative)

StupendousMan (69768) | about 8 years ago | (#15952674)

Can you comment on whether the data support a candidate such as wimps, machos, etc ? (or am I betraying my ignorance with these acronyms

This data provides no evidence for the makeup of the dark matter.

Other observations suggest that the dark matter is not Massive Compact (Halo) Objects, or MACHOs. The idea that dark matter might be composed of some sort of Weaking Interacting Massive Particle, or WIMP, is a bit out of fashion these days, but still a possibility, as far as I know.

Re:The new result, in a nutshell (1)

nherm (889807) | about 8 years ago | (#15952699)

Thank you very much for the informative comment.

I don't see any proof... (3, Insightful)

suitepotato (863945) | about 8 years ago | (#15952569)

...just supposition. After reading all this, all I see is that dark matter, which cannot be observed by any means other than gravitational effects on other non-dark-matter matter and seems suspiciously absent from everyday experience and experiment here on Earth, must exist because we think we see mass and energy behaving in a way that goes with our theories, yet we've seen it behave that way before and it is only in recent times we've decided that something is wrong with physics and we need dark matter.

Can anyone say aether? I knew you'd try...

We have next to zero understanding of the quantum vacuum, and don't know for certain if everything should pop in and out there including not only electrons and photons, but antiprotons and neutral pi mesons and everything else too. We do know it exists from many many Earth-side experiments and reams of dead trees covered in equations. We don't know how the potential fields exist which give rise to the fields we know, we don't know how any of them link in all ways to the nuclear fields which we also don't understand too well but we have loads of equations and experiments for those.

So we invent something, call it "dark matter", and look for anything we can then say matches our thought experiments and we can forgo all the careful Earth-side experiments. We just sort of treat the absence of any dark matter here or anywhere near here as one of those Hitchhiker's Guide SEPs.

More science-by-supposition and proof-by-spectacle. Show me the proof. Show me why dark matter has to exist. Prove it out with careful calculation and application to everything across the board. We've set off fifty megaton nukes for crying out loud without a single sign of anything amiss that would suggest we have a giant hole in physics requiring dark matter. We've done experiments on electromagnetic fundamentals, nuclear forces, and so on and along the way, we didn't hear of a need to invent dark matter.

But some people look at the cosmos and decide that despite not truly understanding the whole picture of physics at every scale yet, we can claim that dark matter exists and here's proof. Where in the Nine Hells does this stuff fit with the physics theories they alread promulgate as accepted science to be taught in universities?

It looks like modern aether, and it looks as though anyone buying it will be upset when someone working right along on the regular investigations into quantum physics and spacetime and so on puts it together and says, "oh, here's why that galaxy moves that way. We didn't need dark matter after all..."

Re:I don't see any proof... (4, Informative)

HappyEngineer (888000) | about 8 years ago | (#15952679)

I didn't understand it until I watched the video.

Essentially it goes like this. They see a collision and make an assumption about what it was that collided.

Then, they looked over the area and determined where the mass is right now (from our point of view).

If the assumption about what collided is correct then the result should have been a mass of hot gas that is distributed like you'd expect if a ball of hot gas collided with another ball of hot gas.

Dark matter supposedly only interacts by gravity. Normal matter interacts by gravity plus nuclear and electromagnetic forces. That means that in a collision, normal matter collides with other normal matter while dark matter is merely slowed down and pulled by gravity.

The mass distribution that they observed matched up with the mass distribution implied by the dark matter theory. It can't be accounted for with just normal matter.

The parts of the theory that would need to hold up:
- the assumed initial configuration of the matter before collision.
- the current mass distribution that they observed.
- the calculation about how the collision should behave if it's all normal matter.
- the calculation about how the collision should behave if it's part dark matter.

If those parts hold up then it's a pretty striking discovery.

Re:I don't see any proof... (1)

zed3 (995321) | about 8 years ago | (#15952696)

TFA has a rather elegant proof, as it happens. All the "careful calculation(s)" are in scientific paper, which I gather has not yet been published. This is proof of something that, while we do not know what it is made of, we have called "dark matter".
Also, fifty megaton nukes are peanuts compared to the energies and scales we're talking about here :)

Re:I don't see any proof... (1)

NewbieProgrammerMan (558327) | about 8 years ago | (#15952748)

I am curious to know why you think that setting off big nukes or making observations of EM, nuclear forces, etc. would necessarily have turned up some evidence that dark matter exists....maybe those things just don't involve dark matter. Is QM a modern aether because dropping cannon balls from a tower didn't turn up any evidence for the Uncertainty Principle?

As far as I know, dark matter is something proposed to explain observed behavior at the galaxy scale and larger, not nuclear bombs, EM, or nuclear forces. Many people have formed various hypotheses, made some observations, tried to explain those observations in terms of the available models, and voila: in this research the predictions based on the dark matter hypothesis seem to match up with observations. Sounds kinda like science to me, but what do I know?

It looks like modern aether, and it looks as though anyone buying it will be upset when someone working right along on the regular investigations into quantum physics and spacetime and so on puts it together and says, "oh, here's why that galaxy moves that way. We didn't need dark matter after all..."

If the idea of dark matter turns out to be entirely wrong, then we'll figure it out, and I'll be happy even though I "buy" the dark matter explanation for the moment. Something tells me the folks that did this research would be happy about it, too, because we'd have made progress by ruling out a candidate hypothesis. In the meantime, you're more than welcome to make observations or hypotheses of your own, since you seem to know enough to peg dark matter as a "modern aether."

Re:I don't see any proof... (1)

ChronosWS (706209) | about 8 years ago | (#15952776)

Well, this is how science works. Hypothesis, experiment, conclusion, rinse and repeat. I personally think calling it 'dark matter' tends to cause confusion that it is somehow like normal matter. From TFA, it sounds like dark matter's only shared trait with normal matter is that it causes a gravitational effect. But then maybe that is the physics definition of 'matter' in general.

Age of the Universe? (2, Interesting)

Kaenneth (82978) | about 8 years ago | (#15952584)

I had read that if the universe were infinite that the sky would be blindingly white from all the old light from old stars, which is one of the reasons that a Big Bang (or other creation) was assumed to have happened.

But if there are dark clouds that can absorb the light, could there be stars further than 13ish billion light years away, that are simply obscured?

olbers paradox (2, Interesting)

cinnamon colbert (732724) | about 8 years ago | (#15952647)

that the night sky is not the temp of the suns surface is called olbers paradox http://jersey.uoregon.edu/~imamura/123/lecture-5/o lbers.html [uoregon.edu] .
I believe the resoluiton of this paradox is one of hte outstanding successes of the expanding universe idea discoverd by hubble

I feel.. (1)

T-Ranger (10520) | about 8 years ago | (#15952588)

Less bad about the Dark Matter futures I purchased when GOOG hit $87.

So funny (-1, Flamebait)

cubicledrone (681598) | about 8 years ago | (#15952593)

Science-is-infallible types claim to know and understand the universe. For man to stand before the resplendence of creation and claim to know anything is the height of arrogance.

The truth is we know nothing, and what we do know is either incomplete or wrong.

Re:So funny (3, Insightful)

jjohnson (62583) | about 8 years ago | (#15952646)

We know nothing, and yet you can post bitchy comments to slashdot, on a computer, connected to the Internet, powered by a physical plant hundreds or thousands of miles away piping electricity directly into your laptop, and then watch a show on TV over cable distributed by satellite.

I'd hazard a guess that we actually do know a thing or two.

Re:So funny (0, Flamebait)

cubicledrone (681598) | about 8 years ago | (#15952666)

We know nothing,

Correct.

on a computer, connected to the Internet, powered by a physical plant hundreds or thousands of miles away

Oh yeah. Computers. The pinnacle of human knowledge. Right before the cursor freezes.

We know a thing or two, but we can't feed everyone. We have satellites orbiting the Earth while people live on sidewalks.

We know nothing.

Re:So funny (1)

Xayma (892821) | about 8 years ago | (#15952751)

You are assuming that with knowledge comes compassion which isn't correct. We could house everyone, however, housing everyone where they want with the conditions they want is a different matter.

Re:So funny (1, Offtopic)

bersl2 (689221) | about 8 years ago | (#15952825)

We know a thing or two, but we can't feed everyone. We have satellites orbiting the Earth while people live on sidewalks.

What are you going to do about it? Give arbitrary power to somebody, who will feed and house the poor with the wealth of the rich? You think some form of collectivism wouldn't quickly degenerate into totalitarianism?

We are what we are. We can only build on what we have previously done. There is no magic of the gods that will allow us to become a species of greater beings; that only happens through the analysis and synthesis of our environment and our own imaginations.

Please keep in mind that even the best of us have flaws, and that the worst have many, many more.

credible and accurate (5, Funny)

10100111001 (931992) | about 8 years ago | (#15952602)

This Account Has Exceeded Its CPU Quota

I haven't yet read this article due to it being slashdotted, but I'm sure it is at least as credible as the story about the new source of free energy from magnets and as accurate as the one that says goldfish are smarter than dolphins.

Re:credible and accurate (2, Funny)

Konster (252488) | about 8 years ago | (#15952654)

doo...doo...doo... Hey! Where did that cool plastic castle come from?

Question: (0)

Anonymous Coward | about 8 years ago | (#15952607)

Did they get any pictures of Nibbler?

Oh noes! (1)

alliekins (990662) | about 8 years ago | (#15952617)

And a scant few minutes later... SLASHDOTTED

Dark matter explained by Free Energy (1)

MKatz528 (996930) | about 8 years ago | (#15952663)

AP: On August 21st, 2006, three scientists who claimed the extrordinary proof of the discovery of dark matter were sued by an Irish company, Steorn, for patent infringement and copyright violation, following the company's announcement of technology to produce 'free energy.' American Physicist Josiah Willard Gibbs could not be reached for comment.

Kanye West says.. (5, Funny)

saboola (655522) | about 8 years ago | (#15952669)

George Bush hates dark matter

Re:Kanye West says.. (1)

MKatz528 (996930) | about 8 years ago | (#15952691)

So does George Allen [washingtonpost.com]

Re:Kanye West says.. (0, Insightful)

Anonymous Coward | about 8 years ago | (#15952715)

Kanye West is about as useful as used toilet paper.

MOND (4, Insightful)

MasterPlaid (731392) | about 8 years ago | (#15952692)

From the title - "This result doesn't rule out alternate gravity theories like MOND". Actually, this directly rules out MOND. That's a big part of the point of the experiment.The idea is that the mass in these clusters doesn't come from the obvious sources of visible matter (the gas), as it would in a MOND or normal gravity scenario, but rather from the invisible (i.e., dark) matter.

Re:MOND (2, Interesting)

Carmelbuck (921788) | about 8 years ago | (#15952724)

Well, AFAIK even most of the MOND folks have acknowledged that some dark matter is necessary. E.g., even when a MOND theory looks like it can explain galactic rotation curves, it doesn't fully explain galaxy clusters or come close to explaining cosmological observations.

The MOND people (generally) aren't kooks. They're just pushing in different directions, which is a good thing. But yes, this does make it even harder for them.

Re:MOND (2, Interesting)

BTO (604614) | about 8 years ago | (#15952781)

No, it's just that MOND alone can't explain this. Reality might still be accurately described by MOND + WIMPs or somesuch combination.

Dark Matter Ate My Baby (1)

CheeseburgerBrown (553703) | about 8 years ago | (#15952710)

Or, er, rather dark matter ate their server.

This suggests that dark matter may not only be dark in terms of information, but also dark in terms of disposition, ie, evil; eg Doctor Who telling off Satan in the "timeless space between worlds."

Ahem.

Dark matter has a bad attitude. That's the bottom line. It isn't seen because it doesn't want to be seen.

I suggest we all make offerings and sing around a dark matter-shaped totem, with fire and sacred wine. Ask yourself: what has good-side-of-the-force matter done for you lately? Nothing, that's what. It's time to demand a matter that delivers on the promise of nothing.

...Er, much like this post.

wheres the proof? (0)

Anonymous Coward | about 8 years ago | (#15952772)

There is no proof without some dark matter to examine.

IN SOVIET RUSSIA (0)

Anonymous Coward | about 8 years ago | (#15952792)

in soviet russia, dark matter discovers you!

(sorry...)

Think outside the box (1)

phaetonic (621542) | about 8 years ago | (#15952798)

Someone discovered the existance of Vergon 6

No proof of physical theories (0)

DoofusOfDeath (636671) | about 8 years ago | (#15952811)

You generally can't prove a physical theory, because you're not sure that the theory will hold in the future or under circumstances you didn't measure.

A better headline would be, "Dark Matter once again not disproven." :)

Well of course dark amatter now exist. (1)

3seas (184403) | about 8 years ago | (#15952840)

Since the Irish company Steorn figured out free energy thay have yet to figure out it creates dark matter
Or that its really not breaking the laws of physics.
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