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A visualization of particles jets in the CMS. Yellow is the path of the particles, while blue and red represent energy detected from the particles.  (Source: CERN/Imperial College of London)
Discovery of dark matter's behavior would solve many outstanding mysteries in physics

Dark matter makes up five times more of the universe's mass than visible matter (~25% vs ~5%), yet scientists have yet to directly observe this ultra-abundant substance.  Scientists also have yet to observe dark energy, which may well beat out normal energy in universal abundance.  This lack of direct observations means that scientists know precious little about two of the most important physical components of our universe.

That could soon change.  CERN's Large Hadron Collider, a 17-mile long circular underground track that is chilled to almost zero degrees Kelvin, is recording incredibly violent collisions, the likes of which haven't been seen since billions of years ago.  Those collisions will likely produce exotic substances like dark matter, which will be analyzed by the LHC's instruments, unlocking long debated mysteries of physics.

Scientists think they are making progress in the hunt for the SUSY – also known as supersymmetric particle, or 'sparticle'.  Scientists believe the sparticle may be the mysterious dark matter, given its theoretical stability.

In order to detect sparticles, scientists must probe the matter resulting from the collision for the absence of energy and momenta signals -- the sign that a sparticle was produced, rather than a standard particle.  This lack of energetic emissivity is the reason why dark matter is dark -- it does not transfer energy to photons, like standard particles.

More specifically, the researchers are trying to detect a "jet" of particles traveling in the same direction, post proton-beam collision, that lack a significant amount of detected energy and momentum.  

Professor Oliver Buchmueller [profile], a faculty member at the Department of Physics at Imperial College London who is doing research at CERN, describes the LHC team's findings, stating [press release], "We need a good understanding of the ordinary collisions so that we can recognise the unusual ones when they happen. Such collisions are rare but can be produced by known physics. We examined some 3-trillion proton-proton collisions and found 13 'SUSY-like' ones, around the number that we expected. Although no evidence for sparticles was found, this measurement narrows down the area for the search for dark matter significantly."

The CMS (compact muon solenoid) detector was co-designed by faculty at the Imperial College, one of Europe's best physics schools.  

Professor Geoff Hall [profile], another Imperial College physics faculty member working at CERN, describes the recent detection of "SUSY-like" streams of particles, stating, "We have made an important step forward in the hunt for dark matter, although no discovery has yet been made. These results have come faster than we expected because the LHC and CMS ran better last year than we dared hope and we are now very optimistic about the prospects of pinning down Supersymmetry in the next few years."

Later this year, physicists will run more trials, which they hope will verify the existence of dark matter in the stream.  They also hope that the theory of supersymmetry will be verified as an accurate description of dark matter, allowing the Standard Model of particle physics to be officially extended.

Looking ahead there's also much hope that the higher-energy collisions might yield a legendary Higgs boson, which would offer much more insight into the behavior of the universe.  The LHC's other major detector -- ATLAS (A Toroidal LHC ApparatuS) -- was designed to search for the Higgs boson.



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RE: Wait
By Azethoth on 2/1/2011 9:45:35 PM , Rating: 3
Thats just wrong. The whole point about dark matter is that it barely interacts with regular matter. Possibly only through gravity. Neutrinos are other (already observed and proved objects) that barely interact. They are created in the sun and trillions pass through you and through the entire earth all the time and only very infrequently do they collide with something.

As for dark matter being undetectable, thats not correct either. We can see its gravitational effects and there are observations of some galaxies after they collided where the dark matter can be "seen" to be doing its own thing separately from what the regular matter (suns and gas) are doing.


RE: Wait
By ShaolinSoccer on 2/2/2011 4:29:01 AM , Rating: 2
Or maybe you're just seeing "gravitational effects"? How can you or any scientist on this planet possibly know what gravity does on a galaxy or on a universal scale? How do you know there is a big bang? What if there are multiple big bangs? Then what? We can only see so far in the universe and the data we see at that range isn't enough to really prove anything! So what if we see galaxies spreading apart? That doesn't mean there is only ONE big bang. That only means we can "observe" what we can from our perspective. For all we know, all the data we have collected about our universe could be totally wrong. Quit acting like it's automatically right just because someone went to school and says it's right. We don't even have a clue what black holes are or if they even exist. All we see are massive emissions of xrays from where we think black holes are, jets shooting away from their poles or objects orbiting them. All these "theories" are interesting but you cannot EVER say they are fact! For all we know, dark matter doesn't exist at all and our calculations about the universe are wrong and that is why we "create" dark matter in our theories...

I really don't think our electronics are capable of coming close to what the uni/multiverse is made up of. If dark matter really does exist, maybe we need to start making things out of dark matter in order to really understand what dark matter is. Afterall, right now, we're using instruments made of 'matter' to study the universe....


RE: Wait
By AssBall on 2/2/2011 10:11:05 AM , Rating: 2
quote:
Or maybe you're just seeing "gravitational effects"? How can you or any scientist on this planet possibly know what gravity does on a galaxy or on a universal scale?


Maybe you heard of Tycho Brahe?

Just because you don't get it doesn't mean its impossible for everyone else to understand.


RE: Wait
By MrBlastman on 2/2/2011 11:14:53 AM , Rating: 3
Well, see, there's something to be said for all this and that is this accelerator (which is amazing) is basically built around discoveries related to "Particle" physics--your fermions and bosons. It is a "particle accelerator" after all, and the detecting equipment serves as a solution for that purpose.

What you are getting at alludes to a conflicting and contrasting gap in physics--those physicists who follow down the straight and narrow path of "particle physics" and those who follow down the path of "string theorists." Both in different ways seek to eventually solve the same problem--finding a way to unify quantum physics with general (and somewhat special) relativity. As is right now, they are not completely compatible so we're going to great lengths to find a way to make them "work" together.

It would be negligent in every way to completely dismiss one avenue or the other--and is absolutely as negligent to be remiss in even mentioning the other, "string theory" in the context of this article. You do mention one thing:

quote:
All these "theories" are interesting but you cannot EVER say they are fact!


I think you made a fatal mistake in presuming that we can never say they are fact. You see, this is the burden of science--to formulate hypothesis and theories and then, to set out and collect data through experimentation and observation to prove these theories. If science were to function properly--eventually, with diligence... and given ample time (assuming humanity does not destroy itself in the process--which it is inevitably bent on doing), we will find "yes" or "no" answers to many of our "questions" (theories).

You are onto something here though,

quote:
I really don't think our electronics are capable of coming close to what the uni/multiverse is made up of. If dark matter really does exist, maybe we need to start making things out of dark matter in order to really understand what dark matter is. Afterall, right now, we're using instruments made of 'matter' to study the universe....


It is entirely possible that our universe is not a sole universe at all. To witness the mechanics of all of this, you've got to step into M-Theory and beyond, explore the concept of strings and be somewhat reticent in accepting the concensus of particle physics and their debunkment in the past of string theory as "wizards and witches." This "dark matter" could in fact not be standard matter indeed, but instead the fabric itself and its various kinks and curves due to hyper-gravitational after-shocks spanning back to billions of years. Heck, even with the most recent observation of a 12.5 billion year-old galaxy, if you step aside from the magnificence of this discover, it unto itself brings into question whether or not our universe is potentially even as old as we estimate, the distances involved, the speed of gravity and beyond. The proverbial "door" to our own expanse, well, the answer to it could lie in this dark matter and these multi-dimensional strings that theoretically we can not even observe due to the size of them.

Yes, we really do _not_ know what our universe is, quite yet at least. I think it all boils down to answering the question "What is nothing?" rather than "What is something?" which we have all been stuck on for centuries.


RE: Wait
By TSS on 2/2/2011 12:20:11 PM , Rating: 2
Lol make instruments out of dark matter? Instead of saying " how can they know", how about you tell us a way to "make" something out of a material we know affects nothing but gravity.

You're also basically saying go detect something that interacts with nothing but gravity, without using gravity.

Because if you do use gravity and specifically, gravitational lensing (gravity bends light, trace the light back to see the bend of gravity to look whats there), you can see and even catalogue dark matter. We already know where most of it is - in a halo around galaxies.

Which solves the problem of the spin of galaxies - galaxies spin just as fast at the center as they do at the tip of the spiral. If you think of a crane, if the base turns, the tip of the crane doesn't go really fast but lags behind twisting the metal. The visible mass in galaxies is about 1/10th what is needed for this to occur. The OBSERVED mass of dark matter through gravitational lensing is exactly the amount needed to counter this.

We know dark energy is there because the universe is expanding, and the rate of expansion is expanding. That's the same as throwing a ball in the air, and instead of it comming back down, it goes up and into space faster and faster. Something is pushing the galaxies away from eachother, despite the huge gravitational pulls.

If there was just dark matter and gravity, The universe should either be constant or collapsing onto itself. At the very least, the rate of expansion should be declining, but as it is, it's increasing. If you want to rip on ANYTHING, dark energy is a good candidate because other then the above, we have no clue what it is, or why it's doing what it does.

Oh and we have observed black holes. Through gravitational lensing, through watching the stars at the center of the galaxy orbit at an incredible speed around a supermassive object we cannot see in any way, and watching a super nova blow up then that part of space going dark.

Seriously go watch the history channel. The discoveries made in the past 2 decades concirning deep space rival the advance we've made in computing. And very little wheren't predicted in einstein's theories.


RE: Wait
By JediJeb on 2/2/2011 1:38:28 PM , Rating: 2
quote:
You're also basically saying go detect something that interacts with nothing but gravity, without using gravity.


Doesn't the fact they are using the LHC and its detectors to try to observe dark matter particles say the best physicists on earth are trying to do just that, observe something that only interacts with gravity by using something other than gravity to detect it?

quote:
Which solves the problem of the spin of galaxies - galaxies spin just as fast at the center as they do at the tip of the spiral. If you think of a crane, if the base turns, the tip of the crane doesn't go really fast but lags behind twisting the metal. The visible mass in galaxies is about 1/10th what is needed for this to occur. The OBSERVED mass of dark matter through gravitational lensing is exactly the amount needed to counter this.


But if you think of a CD or LP, the whole disk spins at the same rotational rate, though linear velocity is faster at the outer edges. Also the stars in the galaxy are not connected by a hard physical link as the crane is in your metaphor so they are being propelled by different forces.

quote:
We know dark energy is there because the universe is expanding, and the rate of expansion is expanding. That's the same as throwing a ball in the air, and instead of it comming back down, it goes up and into space faster and faster. Something is pushing the galaxies away from eachother, despite the huge gravitational pulls.


This one also gives me pause when thinking about it. We say the rate of expansion is increasing because we observer greater red shifts in the galaxies that are farther away. But that seems counter to what we should observe, since a greater red shift means something is moving away at a higher velocity. If galaxies were moving away from us at higher velocities 10 billion years ago, while other galaxies we observe are moving away as slower velocities millions of years ago,(closer galaxies have less red shift), wouldn't that say the expansion is slowing down? We can not take a snapshot and say look these farther galaxies are moving faster and the closer ones are moving slower and extrapolate that expansion is increasing because of the temporal displacement of the data being used( every point of data is taken from a different time as well as place).

quote:
Oh and we have observed black holes. Through gravitational lensing, through watching the stars at the center of the galaxy orbit at an incredible speed around a supermassive object we cannot see in any way, and watching a super nova blow up then that part of space going dark.


This goes back to the first, seems we are observing the center of the galaxy moving faster than the outer edges, or were the first comments wrong in that the outer edges are not actually moving as fast as the inner parts? IF the laws of gravity break down at the very small scale, how do we know without a doubt that they do not also vary at the very large scale. We observe it in almost all galaxies, that they seem to not follow what we have set as our laws of gravity, but instead of questioning the laws of gravity we have postulated, we instead say the laws can not be wrong therefore something else must be causing it. If we never prove dark matter exists, will we then have to say the laws of gravity could be wrong or do we have to make up some other explanation?


RE: Wait
By Iaiken on 2/2/2011 1:23:48 PM , Rating: 2
quote:
Afterall, right now, we're using instruments made of 'matter' to study the universe....


Which are capable of incurring and observing forces... forces that allow those devices to interact or sense things like neutrinos and dark matter. Once upon a time, people like you thought the idea of accelerating matter with electromagnetic force to a degree of accuracy achieved by the LHC an impossibility also.


RE: Wait
By zmatt on 2/2/2011 10:19:16 AM , Rating: 3
No I understand it just fine. I'm just calling BS on the whole thing. Saying that a large portion of the matter in the universe does not directly interact with us and cannot be directly (that bit is important) observed is a cop out. Sure neutrinos are there, but they are hardly everywhere or a common concern. Neutrinos have also been directly detected, dark matter and dark energy have not. In fact the only thing currently behind them is some math and conjecture. Without empirical evidence you have nothing. Who is too say that the math isn't wrong?

It's much more logical to see the observed mass and gravity discrepancy and think that maybe we don't fully understand the fundamentals of gravity (we don't) instead of inventing a completely new form of matter to try and explain it. Dark matter and dark energy is nothing more than intellectual mutual masturbation.


RE: Wait
By MrBlastman on 2/2/2011 11:18:01 AM , Rating: 3
So let me get this straight,

quote:
I'm just calling BS on the whole thing.

quote:
Without empirical evidence you have nothing. Who is too say that the math isn't wrong?


Do you think we should just throw out "theory" completely and instead rely absolutely on what our eyes can see, our ears can hear and our skin can feel through touch?

That would, I lament, be a tragedy if we were to do that.


RE: Wait
By zmatt on 2/2/2011 5:42:09 PM , Rating: 1
See now you are putting words into my mouth. That is not at all what I said. What I am saying is that a legitimate scientific theory must be supported by the evidence. One builds a theory around evidence, not the other way around. The hypothesis of dark matter and dark energy has existed for over a decade, millions have been spent, and there is not a shred of evidence to support it actually does exist. The logical ting to do would be to admit that the hypothesis is not supported by the evidence and formulate another one. Doing anything else is unscientific.


RE: Wait
By MrBlastman on 2/3/2011 10:35:15 AM , Rating: 2
So when Aristotle proposed somewhere around 384-322 B.C. that the world was round, by what you are saying, since nobody was able to sail around the world and prove it within say a hundred or so years, they should have completely thrown out the notion and started over?

Guess what? It wasn't until around 1519 - 1522 A.D. that Magellan sailed around the world and proved it to actually be true that the world is spherical! Science sometimes takes time... time measured in millenia and multiple centuries and doesn't always happen overnight.

BUT--you do have a valid point--in that it is smart to formulate a different hypothesis. One has already been formulated... read about it in M-Theory. Google Brian Greene and Edward Witten and read all about it.


RE: Wait
By kingius on 2/3/2011 11:02:30 AM , Rating: 2
There is evidence that people have been sailing around the world for tens of thousands of years, Aristotle wasn't really saying anything new. He was going against the establishment of the time though, which (surprise surprise) claimed they knew everything... sound familiar?


"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -- Isaac Asimov

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