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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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Wait
By zmatt on 2/1/2011 2:23:51 PM , Rating: 0
so they haven't actually found it, they just think they can with the LHC. This is hardly news. It was one of the posted goals of the LHC. Although, if it takes something as exotic as a massive particle accelerator to make the stuff, then how abundant can it be? They have been searching for it in nature for over a decade now and have yet to find any evidence of it's actual existence. In my admittedly not expert opinion I think this has gone beyond reasonable conjecture. If it was there and as abundant as they claim we would have found it by now. I think we simply have gravity wrong (again) and wont admit it.




RE: Wait
By smitty3268 on 2/1/2011 3:02:27 PM , Rating: 2
No one believes they can just dig a mine on earth and find the stuff lying around. The idea is that it was creating during the big bang, or possibly around black holes, stars, and other high energy phenomena.

I really have no idea if it exists or not, but just because we haven't found it yet doesn't mean it doesn't exist. And if they can't find it at the LHC, then that will strengthen the argument that maybe it doesn't exist, and someone will come up with an alternative explanation.


RE: Wait
By zmatt on 2/1/2011 6:34:59 PM , Rating: 1
indeed I don't expect to find it in the ground either. However I find it very hard to believe that something that makes up such a large part of the universe is conveniently undetectable. that sounds a lot like "ether" to me and we all know how that worked out. My point is there is a point in the scientific world where you have to look at your hypothesis and see if the data supports it or not. The data does not support dark matter and dark energy, and has not for quite some time. And even if they sound something similar to it in the LHC, for the theory to be correct it would have to be extremely common in the universe. If you can only find it under special conditions then it hardly meets the requirements.


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?


RE: Wait
By Risforrocket on 2/6/2011 4:07:18 AM , Rating: 2
quote:
...that sounds a lot like "ether" to me and we all know how that worked out.


Actually, the ether theory is correct, essentially. The "ether" is a field of energy nominally in a neutral state permeating the entirety of the universe as we don't know it.

Our theory of matter and gravity are very much incomplete. However, this does not indicate there is no dark matter. Dark matter is an example of how modern science chooses what is real. This, is what is important here.

No thing can be proved or disproved. I wish people would understand this. It is essentially a choice to believe the evidence presented for a proof. Thus, it is merely a choice to believe. Once this is understood, real science can happen. I will not be as structured and that is a good thing.

The search for dark matter will uncover secrets and that is what "matters." Our understanding of gravity and it's intrinsic relation with electromagnetics will occur when we are ready to accept the truth of these things.

The direct counter to your argument here, zmatt, is that our inability to see dark matter does not diminish the theory of dark matter as it is in the nature of dark matter for it to not interact with our reality as we know it. I suspect that you know this and are just not willing to use your real argument against dark matter. This will prove to be counterproductive for you. As for me, I question everything.


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.


RE: Wait
By Adonlude on 2/1/2011 4:33:13 PM , Rating: 3
So becuase they have been looking for a decade and not found anything it must not exist? We would never have found the majority of the elements on the periodic table with that attitude, much less any subatomic particles. Sometimes theory has to wait for technology to catch up.


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