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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 tng on 2/1/2011 3:52:52 PM , Rating: 3
quote:
I think we simply have gravity wrong (again) and wont admit it.
I think that you are partly correct.

Not being a physicist, and knowing that I am probably wrong, I feel that the problem with gravity is that it may react differently at different scales. Hence when they first discovered that the Milky Way was rotating to fast they invented invisible matter to compensate for the extra gravity they said had to be there.

We know very well how gravity works on Earth/Moon and the local solar system, so it should work the same way galaxy wide right? Do we really think that most of the universe is made up of matter that we can't just not see, but have not even after years of effort can't even find?


RE: Wait
By B3an on 2/1/2011 4:41:25 PM , Rating: 3
It wasn't long ago until humans could see or detect atoms and the like, even though they're literally everywhere and you're made of them. Before that it was the same with air/wind.
Yet for some reason you have trouble understanding that we cannot yet detect dark matter?

I dont know why you people post this stuff when you have have no understanding of it whatsoever and even admit that you're probably wrong.


RE: Wait
By inighthawki on 2/1/2011 5:45:52 PM , Rating: 3
The difference here is that the matter around us and wind/air is quite clearly there. You can feel, see, hear, it, etc, we simply could not prove that it was made of "atoms" until we saw it at that level.

Dark matter, on the other hand, cannot be seen, nor touched, therefore it is simply a theory. Just because we could not detect atoms didn't mean that we thought matter itself was a theory because we could actually interact with it!

quote:
I dont know why you people post this stuff when you have have no understanding of it whatsoever and even admit that you're probably wrong.

Because they are proposing the rational idea that someone may have simply been wrong. We still do not know much about gravity and how it works, so the possibility of our gravity equations and theories simply being wrong as still plausible, and we must keep that in mind as an alternative to searching for dark matter, a substance that may not even exist since we cannot see or interact with it.


RE: Wait
By vortmax2 on 2/1/2011 6:16:33 PM , Rating: 3
Humanity's biggest problem: Pride.


RE: Wait
By Goty on 2/1/2011 6:20:34 PM , Rating: 2
You can't touch any other type of matter any more than you can dark matter. When you "touch" something, you're just interpreting the electromagnetic interaction between the atoms that make up your hand and whatever you're "touching". Detection of dark matter is no different, it's just an interaction using a different force (gravity, in this case). The fact that you don't interact with it in the same way doesn't mean it isn't there.


RE: Wait
By vortmax2 on 2/1/2011 6:22:36 PM , Rating: 2
Isn't your post a quote from The Matrix? LOL


RE: Wait
By wired00 on 2/1/2011 8:18:53 PM , Rating: 4
Do not try and bend the spoon. That's impossible. Instead... only try to realize the truth. There is no spoon. Then you'll see, that it is not the spoon that bends, it is only yourself.


RE: Wait
By inighthawki on 2/1/2011 10:45:26 PM , Rating: 5
But my point is that you can observe the existence of the matter itself. The touch produces an electromagnetic repulsion, it reflects light, etc. Dark matter cannot be observed (assuming it exists) with current technology. Please don't try to be technical with wordplay.

quote:
The fact that you don't interact with it in the same way doesn't mean it isn't there.

I did not say that it didn't, I just said we need to be more open to the idea that it MIGHT not exist. Should we stop looking? No, but we surely shouldn't stop looking into alternatives reasons either.


RE: Wait
By Goty on 2/2/2011 9:35:23 AM , Rating: 2
We can't observe molecular hydrogen in the interstellar medium, either, but we know it's there. You know how we know? We observe its effects on its environment, the same as we observe the effects of dark matter on its environment. The only difference is that we know what types of particles make up molecular hydrogen and we're still trying to figure out what makes up dark matter. We KNOW that "it" exists through observational evidence, we just need to find out what exactly "it" is.


RE: Wait
By JediJeb on 2/2/2011 1:58:45 PM , Rating: 2
Question is how do we know it is dark matter and not just molecular hydrogen that we can not see?


RE: Wait
By Goty on 2/2/2011 3:14:08 PM , Rating: 2
There are other species of gas present in the molecular hydrogen that act as tracers of the molecular hydrogen. There will also always be a small amount of neutral and singly ionized hydrogen present as well that we can detect.


RE: Wait
By inighthawki on 2/2/2011 4:10:53 PM , Rating: 3
But that's the thing, one of your examples exists, we know it exists. The "it" you're referring to, though, may not even exist at all.

Dark matter is just a theory to explain what we observe, it is by no means the end all of possibilities. How do you know that "it" is not simply an unobserved function of gravity, or another unknown force?

Again, I am NOT saying dark matter doesn't exist, just that we should all be open to the possibility that it could also be something else. It just seems a little far fetched to believe that a made up type of invisible matter that makes up the majority of our galaxy (yet we cannot obtain) is the only possible solution to the problem.


RE: Wait
By Goty on 2/2/2011 8:30:09 PM , Rating: 2
Dark matter is the simplest, most likely explanation and it explains a much larger range of phenomena that any form of MOND has ever been able to. The difference is so staggering and dark matter is such an elegant solution, requiring no new physics as far as astronomers are concerned, that, until it can be concretely disproven, it really is the best avenue of progress.


RE: Wait
By kingius on 2/3/2011 11:06:46 AM , Rating: 3
Elegant?

They just went... see that big number we need to put here or the maths just doesn't work? Yes, that. That's ... dark matter. And the other one there? Yes, that big one. That's... dark energy.

It can't be that the maths is wrong. No sir. We can't have just got it wrong. Nope. Dark matter. Dark energy. See? We weren't wrong.


RE: Wait
By tng on 2/3/2011 6:16:33 PM , Rating: 2
quote:
until it can be concretely disproven, it really is the best avenue of progress.
Which is why so many of us that stand of the edge of science look in and shake our heads.

New ideas for many mysteries in the world of science are immediately shot down, because they don't match what is already generally accepted, even if the generally accepted idea is far from being proven.

I have heard many scientists go on about how open minded science in general is. Really it is just the opposite from what I have seen.


RE: Wait
By Spinne on 2/2/2011 1:00:27 AM , Rating: 2
It's always OK to posit that the guys doing the research are 'wrong' because they don't have results yet and while that may be the case, it's not very helpful. Unless you can explain why you think they're on the 'wrong' track, it's just as easy to say: NO, you're WRONG about them being wrong! :D


RE: Wait
By kingius on 2/3/2011 11:10:35 AM , Rating: 2
Once upon a time, the scientific method defined what science is. You did some experiments, discovered something, published your results and others could follow the same steps to reproduce them.

Not so today. Today, all you have to do is think of an idea, express it using mathematics and it goes into the umbrella of science.


RE: Wait
By maugrimtr on 2/2/2011 8:19:32 AM , Rating: 2
Gravity is actually very well understood at the large scale. There are only doubts about it at the very small scale, and those are largely to do with how weak it is compared to other forces (such as those binding atoms together).

When people propose some weird gravitational theory where gravity must by definition depart from all its observed qualities, it is not rational in the slightest. Is it far more rational to utilise the scientific method, and that method suggests that with gravity as observed, there must be additional matter somewhere to explain the gravity binding galaxies together. The simplest and most rational explanation is that there is extra matter, that this extra matter exerts a gravitational force, and that it cannot be directly observed.

Complaining about the lack of direct observation is likewise irrational. We can't see air - but it's there. We can feel it, just like galaxies feel the pull of dark matter. We can't see electrons, but they are there and they power our laptops and PCs. There's a lot of stuff we cannot directly observe without first inventing the tools necessary to do so - and even then we end up with indirect evidence unless someone has actually seen an electon and not merely its sideeffects? ;)


RE: Wait
By Iaiken on 2/1/2011 6:31:26 PM , Rating: 3
quote:
It wasn't long ago until humans could see or detect atoms and the like, even though they're literally everywhere and you're made of them.


Indeed.

The scientists of the Manhattan Project who undertook the great endeavor of splitting the atom were essentially working blind. At the start they didn't even have access to simple computers and everything was done by hand or by slide rule.

Many explanations and ideas regarding fission arose and were discredited. It even took substantial guesswork and elimination to figure out suitable a suitable candidate for fission in U-235. The vast majority of the effort on the project was actually spent on figuring out methods for separating enough U-235 from ores that were primarily composed of the chemically identical U-238 or creating breeder reactors to produce plutonium.

Building the actual bombs was a comparatively trivial engineering problem once they had enough enriched uranium or plutonium for the cores. The gun-type design of "Little Boy" was so simple that they didn't even bother to test it. The amount of enriched uranium was so small at the time, that the idea of testing.

It's amazing what a little imagination, unwavering government support and essentially unlimited resources can achieve.

It's so simple in fact, that in 2004 Joe Biden was presented with a crude-but-functional nuclear device that was built by university students from legally obtainable products. All it needed was a quantity of enriched uranium the size of a softball. This once-great mystery is now so well understood that the abstract processes and even the math behind it is taught most high school chemistry/physics classes.


RE: Wait
By FITCamaro on 2/1/2011 8:41:13 PM , Rating: 2
If I remember correctly, the two bombs dropped on Japan didn't even make all their uranium explode or whatever the term is.


RE: Wait
By jeff834 on 2/2/2011 3:10:02 AM , Rating: 2
React would probably be acceptable.


RE: Wait
By Iaiken on 2/2/2011 9:14:09 AM , Rating: 2
Doesn't matter if the designs didn't work to optimal efficiency. They still instilled so much terror into the population that they went from being militaristic jingos to pacifists almost over night.


RE: Wait
By Iaiken on 2/2/2011 9:23:07 AM , Rating: 2
quote:
The amount of enriched uranium was so small at the time, that the idea of testing was seen as a terrible waste of time and resources.


Fixed.


RE: Wait
By UNHchabo on 2/8/2011 1:21:29 PM , Rating: 2
quote:
The gun-type design of "Little Boy" was so simple that they didn't even bother to test it.


While you are correct, your wording makes it sound as if Little Boy (dropped on Hiroshima) was the first nuclear bomb to be set off. This is not true:

http://en.wikipedia.org/wiki/Trinity_%28nuclear_te...


RE: Wait
By Goty on 2/1/2011 6:15:02 PM , Rating: 3
You're thinking of Modified Newtonian Dynamics, which has been widely discredited for quite some time. There is no observational evidence to support the theory, while there are numerous tests for dark matter that show that there IS in fact something there, we just don't know exactly what, yet.

A good example of the difference between the two (MOND and dark matter) is observations of the bullet cluster. MOND does not offer a satisfactory explanation, whereas simulations involving dark matter can reproduce this arrangement quite easily.


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