Dark Matter Particles May Have Been Detected

During two seminars at Stanford and Fermilab on Thursday, researchers described signals for two events detected deep in an old iron mine in Minnesota that might mark the first detection of dark matter — or not. The presenters said the chances that the signals they detected were caused by something other than "neutralino" dark matter particles was 23 percent. "One source indicates that we'd need less than 10 total detections within the CDMS' range in order to have a high degree of confidence in the results." The NY Times describes the Cryogenic Dark Matter Search methodology: "The cryogenic experiment is nearly half a mile underground in an old iron mine in Soudan, Minn., to shield it from cosmic rays. It consists of a stack of germanium and silicon detectors, cooled to one-hundredth of a degree Kelvin. When a particle hits one of the detectors, it produces an electrical charge and deposits a small bit of energy in the form of heat, each of which are independently measured. By comparing the amounts of charge and heat left behind, the collaboration’s physicists can tell so-called wimps from more mundane particles like neutrons, which are expected to flood the underground chamber from radioactivity in the rocks around it." Here are the research team's summary notes of the latest results (PDF).

Comments

It must be true!

[Drethon]

Because scientist's interpretation of what they see is never wrong! When did science start to feel more like religion to me...

Re:It must be true!

[wanerious]

You mean the cautious interpretation that it's only 77% or so likely to be a positive signal? What does it mean that such a forecast is never wrong? I think science feels more like religion when you decide that's how it works. Do you have an alternate suggestion for interpreting this dataset?

Re:It must be true!

[IndustrialComplex]

Because scientist's interpretation of what they see is never wrong! When did science start to feel more like religion to me...

So tell me where they went fairy tale on us here?

Here is just a gross simplification, so I may not be completely accurate, but I fail to see where this is fairy-tale science.

Characterization: Isn't that where we are finding that galaxies aren't behaving as we expect them to, and that behavior is in the form of gravitational interactions which shouldn't happen given the amount of mass which we can see.

Hypothesis:
There is something there which for some reason has a lot of mass, but we can't see it. Literally: Dark Matter

Deduction: If Dark Matter is weakly interacting as is suggested by the fact that we can't currently see it. If we are able to detect an interaction which cannot be accounted for among known particles, you have either discovered dark matter, or some other particle altogether if that detected particle is not massive enough when combined with the rate of interaction and the mass of the detected particle.

Experimentation:

Stick a detector way down in a mine shaft which will help filter out a lot of things which could cause a false positive. Look for interactions which do not match any known possible interactions.

Again, that is grossly simplified, but I don't see the jump in logic you are looking for.

Re:It must be true!

[shawnap]

Because scientist's interpretation of what they see is never wrong! When did science start to feel more like religion to me...

Did you forget a sarcasm tag, because there's nothing in TFA about global warming or evolution that I could see.
Does this fucking troll apply to all science articles now?...

Re:It must be true!

[Mattskimo]

No, only ones that disagree with my worldview.

Re:It must be true!

[Anonymous Coward]

Because scientist's interpretation of what they see is never wrong! When did science start to feel more like religion to me...

Because you are just ignorant and watch too much Faux News.

Re:It must be true!

[Anonymous Coward]

Joe Public: "Well, I don't understand it, so it can't possibly be right."

Re:It must be true!

[Anonymous Coward]

I agree with all of this.

The only comment I have to make in the other direction is that I am uncomfortable with the probabilities that scientists have suddenly started to give - "there's a 77% chance we are completely correct".

Take the climate was somesuch as "there's an 11 percent chance that there will be less than X degrees and a 23% chance that there will be more than Y degrees". Then someone finds that heat radiation works differently from what any of the 11 models (all obviously based on a single model with a few tweaks) predicted. How does that affect the probabilities? Does the probability include the percentage chance that any element in the entire model is wrong? Or is the assumption simply that model inaccuracies will even out on both sides, and chance of error is simply statistically calculated based on the availability of data?

I wish for some good old scientific conservatism, and the need to put percentages on the proportion of 100% correct you are feels a bit dubious.

Re:It must be true!

[Anonymous Coward]

Now you know why some of us aren't keen to demolish our economy in the name of combating anthropogenic climate change.

Re:It must be true!

[Steve Max]

They never said that "it's only 77% or so likely to be a positive signal", or that "the chances that the signals they detected were caused by something other than 'neutralino' dark matter particles was 23 percent". What they said is that there is a 23% chance that, in the total absence of DM particles, the background would generate those two events they found. Or: If they did the same experiment, with the same exposure and analysis (and if DM doesn't exist) hundreds of times, 23% of those experiments would show two or more events.

The chance that you flip a coin three times and get the same side up all three times is 25%, if the coin is honest. This doesn't mean that if you flip a coin three times and get the same side up three times, there is a 75% chance that the coin is not honest.

Going a bit deeper in the statistics, the probability that A happens with the hypothesis B is NOT the same as the probability that hypothesis B is true given that A happened. To "flip" those 23% probability that the background gives you 2 events to a probability that the two events events are caused by the background, you need to apply Bayes' theorem. You can only do that if you use, as prior knowledge, the probability that a dark matter particle exists. This prior can't be defined precisely by anyone, each physicist would give you a different value; so you can't apply Bayes' theorem here without being heavily biased.

What you can infer is that there is a pretty good chance that this was just a background fluctuation, specially since their previous results had zero events (with a similar background expectation). The REAL point that physicists got from the talk was that CDMS reached its limit, and has to be upgraded to SuperCDMS to stay relevant.

Re:It must be true!

[Anonymous Coward]

Does the probability include the percentage chance that any element in the entire model is wrong?

Yes, of course. Why does everyone assume the scientists behind this are stupid?

Re:It must be true!

[Chris Burke]

The only comment I have to make in the other direction is that I am uncomfortable with the probabilities that scientists have suddenly started to give - "there's a 77% chance we are completely correct".

Except it's not even that.

There saying there's a 77% probability that the result was not due to random noise, and that they actually did detect particles that are within the range predicted for neutralinos by Supersymetric Theory. Does that means it's a neutralino? Not necessarily, but it is a pretty strong argument of the "hypothesis -> experimentation -> verification" variety. Does it mean that everything they predict for neutralinos is true, or that Supersymetric Theory is "completely correct"? No.

I wish for some good old scientific conservatism, and the need to put percentages on the proportion of 100% correct you are feels a bit dubious.

Again, they're only putting a percentage on this not being a null result. Your characterization is wrong.

They're being conservative. But they're excited. And when you take a theory as ridiculously successful at making predictions as the Standard Model, make a logic extension to it and then that theory quite possibly has had its first verified prediction, that's not unreasonable.

I remember when scientific skepticism on slashdot involved people taking issue with specific aspects of the experimental procedure. Not people complaining that they don't like the result or how snooty the scientists are using statistics to measure their success.

Re:It must be true!

[Steve Max]

If you read CDMS's paper or watch the talks, you'll see that they never said that "there's a 77% chance we are completely correct" or anything like that. All they said (and all they can say with their data) is that, assuming that DM doesn't exist, the probability for the background alone to generate two events is 23%. Or: their result is compatible with a "Dark Matter doesn't exist" hypothesis, within a bit more than one standard deviation; that means their result is absolutely compatible with the absence of dark matter. We could say they had seen a "hint" of DM if they'd seen three events; they would have detected DM if they had seen 5 or more events, because the chance of a background fluctuation to generate five events is below one in one thousand; then other experiments would try to detect it in other ways, to confirm the discovery.

Don't mistake "scientific" journalists for scientists. If you want the facts, go for them, and you'll see MUCH less hype than what you read in the interwebs.

Re:It must be true!

[Profane MuthaFucka]

If it feels like religion, it's because YOU don't understand what's going on.

When did regular people decide that they were qualified to second guess the experts, WITHOUT having put in the decades of work and received a degree which might indicate they are capable of contributing to knowledge?

Fucking hell, people who can't figure out where an apostrophe, elipsis, or question mark should go are telling me they can out-think Stephen Hawking.

Re:It must be true!

[Anonymous Coward]

This is slashdot. Everyone else is stupid.

Re:It must be true!

[Arancaytar]

Exactly! I keep telling people; Einstein was wrong! An absolute speed limit makes no sense because there's no way I can understand how that would work!

Do you have the email of the president of physics?

Re:It must be true!

[Trails]

That's because your logic is fundamentally flawed. If you were really questioning, and not just accepting everything at face value, you would say this:

Characterization: Isn't that where we are finding that galaxies aren't behaving as we expect them to, and that behavior is in the form of gravitational interactions which shouldn't happen given the amount of mass which we can see.

Hypothe- err, fuck that, I mean PROOF:
It's God. Literally God!! He's got his hand in that galaxy like it was a Jeff Dunham puppet.

Deduction: If God is weakly interacting with the galaxies, all you heathen sciency evolution types are fucked! Richard Dawkins won't be able to save you from getting cornholed by fire demons for the rest of eternity.

Experimentation:
Invoke the spirit of Charles Darwin. Ask him how hot Hell is. Fall on your knees, and hear the Angels sing. Never question God or me again. Now I will call you saved, please deposit $200 into the jar.

That's how you really fight the dogma of science.

Re:It must be true!

[Mister Whirly]

Well, who are you going to believe - a panel of experts with hundreds of years of combined knowledge of the specific subject, or your gut? This so called "intelligence" is just nothing but liberal elitism at it's best.

Re:It must be true!

[blair1q]

Science only feels like a religion because in both people with full knowledge of the arcana speak to the rest of us as though we are children.

The difference is in the veracity of the arcana.

So Science sometimes feels like a religion, while religion proves to be religion.

Re:It must be true!

[athowell]

Dark matters has been over all the news lately, what do you mean you can't detect it... Tiger?

Re:It must be true!

[Gilmoure]

Might have been better if they'd called it Dark Mass, as that seems to be the thing we're twigging to about it all.

Re:It must be true!

[osu-neko]

I think science feels more like religion when you decide that's how it works

When was the last time your minister has said there's a 77% chance God exists? Or suggested further experiments be performed to verify this?

Science feels more like religion when you don't know wtf you're talking about...

Re:It must be true!

[radtea]

Don't mistake "scientific" journalists for scientists.

Yeah, this is typical distorted reporting. The paper is an entirely conventional one putting limits on mass and interaction strength. Some lying idiot in the press decided to hype up the "possibility dark matter has been dectected!" angle, demonstrating once again that no one hates science quite as much as "science journalists", who clearly don't trust that the subject matter is sufficiently interesting to warrant readers paying attention to it unless it is distorted beyond belief.

The details of this detection system and the quality of the analysis and results stand on their own, without needing any hype or misleading spin.

Re:It must be true!

[Anonymous Coward]

Well your not the absolute most well fed troll of all time on /. but you did a pretty damn good job. gg

Re:It must be true!

[Catiline]

When did regular people decide that they were qualified to second guess the experts, WITHOUT having put in the decades of work and received a degree which might indicate they are capable of contributing to knowledge?

In the eighth grade, when I was told that an argument that could be summed up as "Respect my authority!" with no factual backing was a fallacy.

Re:It must be true!

[arminw]

....Do you have an alternate suggestion for interpreting this dataset?...

Not necessarily the data from the experiment in the mine, but a statement from the article referenced.

(...That suggests that either our understanding of gravity's wrong, or there's matter we can't see....)

There is at least one other possibility. Is it just possible, just maybe, that another force is causing the galaxies to move in a way that gravity alone cannot explain? Could it be the electric force which is 36 orders of magnitude greater than gravity?

A number with 36 zeros behind it is unimaginably large. Could a tiny charge imbalance on the galaxy or stars within that galaxy combined with an electric field be a way to explain the data? Why is this possibility of the electric interaction being involved not more thoroughly investigated by mainstream scientists?

I am not saying that this is the answer, but why is this possibility dismissed out of hand by most mainstream cosmologists? Why is the idea of the electric universe relegated to a fringe minority? These people do have an explanation for the data we observe, which does not require the existence of any kind of matter which is not the same as what we have here on earth in every day life. The electric theory also do away with black holes which so far, have only been inferred, but not actually observed in action.

Sometimes, in fact quite often, strange, wild ideas brought forth by people thought to be wacko, turns out to be right in the end. Most often, in science, the simpler, straightforward explanation is the right one. Think of the consternation and ridicule Einstein's theories and quantum physics first engendered from the mainstream science of the day.

Re:It must be true!

[Thing 1]

So Science sometimes feels like a religion, while religion proves to be religion.

<aha>So, you really can prove things with religion! I've been wrong all these years.</aha>

Re:It must be true!

[amRadioHed]

Just because you are incapable of understanding the factual backing doesn't mean there is none.

Re:It must be true!

[wanerious]

Thanks --- I was terribly imprecise in my haste.

Re:It must be true!

[Profane MuthaFucka]

That's not the argument, nor the summary.

The scientists are not right because they are scientists with white lab coat. The scientists are right because their successive theories of the nature of the universe are converging upon the actual nature of the universe.

Re:It must be true!

[Anonymous Coward]

It was called the missing mass hypothesis initially; one of the early guesses was that it was radiation (i.e., photons), but study of the cosmic microwave background radiation precluded that (and also "hot" relativistic particles of matter). It is matter in that it is not radiation or antimatter; it is mostly cold in that it is moving thermally -- at nonrelativistic speeds -- otherwise the CMBR would look vastly different and so would structures like galaxies and galactic clusters; it is dark in that it does not radiate photons (it also does not absorb them).

So,"CDM", cold dark matter, is essentially what it says on the label. (It also does not clump, in part because while it responds to gravitation, it can't emit photons, so when a cloud of dark matter is compressed it is very different than when a cloud of normal matter is compressed -- the latter glows quite brightly (think of the sun) -- CDM would have to shed the gravitationally gained energy through gravitation or weak-force interactions with normal matter).

Likewise, neutrinos are hot dark matter -- they don't emit photons or absorb them, they move relativistically, and they are not photons (or antimatter).

A box of photons has mass. (in the GR sense; you can think of that as mass-energy if you like)

A box of neutrinos has mass.

A box of positrons has mass.

A box of antineutrinos has mass.

So "dark mass" is ambiguous. So is "dark matter", but that's largely because nobody has been able to demonstrate exactly what type of matter it is.

This particular experiment is looking specifically for neutralinos, a (still hypothetical) supersymmetry partner of the neutrino that may fit the requirements of CDM, and which are heavier than neutrinos (in the sense that they do not accelerate to relativistic speeds given a very low-energy nudge like a light particle like a neutrino does).

Re:It must be true!

[PipsqueakOnAP133]

Independently-verifiable conclusions:
I've failed at invoking the spirit of Charles Darwin. Since Charles Darwin existed, but invoking the spirit fails, it's highly likely there's no afterlife.

White male science

[Anonymous Coward]

As a 49 yo feminist grandmother, I reject these results, since they are done by an old boys network of grey haired caucasian scientists.

Re:White male science

[Anonymous Coward]

As a 49 yo feminist grandmother, I reject these results, since they are done by an old boys network of grey haired caucasian scientists.

You left out "capitalist pig", "reactionary", "fascist", and "racist" from your description of the scientists.

Re:White male science

[Anonymous Coward]

As a 49 yo feminist grandmother, I reject these results, since they are done by an old boys network of grey haired caucasian scientists.

Marie Jo, I told you to dust of my PC, not to surf the web.

Re:White male science

[Anonymous Coward]

As a 49 yo feminist grandmother, I reject these results, since they are done by an old boys network of grey haired caucasian scientists.

http://www.fnal.gov/pub/presspass/press_releases/CDMS_Photos/cdms_2_collaboration.JPG

Yep, sure looks like an entire pack of grey haired Caucasian scientists to me -- if I squint really hard and cover up a few people in the photo.

Re:White male science

[Anonymous Coward]

Ah, I see. You didn't get the memo. We'll let it slide THIS time.

Re:White male science

[ceoyoyo]

Now that's fame: to become a Slashdot meme.

Re:White male science

[jo42]

White male science has been looking in the wrong place for dark matter. They should try looking between the ears of politicians. Mod away... :p

Re:White male science

[itlurksbeneath]

Maybe you should have went to college and got a degree in physics then?

Re:White male science

[Anonymous Coward]

As a 49 year old virgin slashdotter, I reject your assertion that this is a meme since the assertion is only based on a handful of copy-cat incidents made by ACs.

Re:White male science

[ZeroExistenZ]

They should try looking between the ears of politicians.

It's true that alot of politicians are corrupted, and not much gets done.

But have you worked in a large company yet, where in order to complete a project different seperated departments with different stakes are involved and all have an own opinion and different expertises?

Enlarging that to "projects in a country" or even on a larger scale, it amases me anything gets done at all, disregarding the intelligence of many trying to push their agenda, stakes and represent their stakeholders (say, in the best case, their voters values.)

The older I get, the more these kindof powers become more clear; friction, weight, opposing views, personal context, agenda, conflicting personal or professional goals, ...

While the joke stands, strong, I do wonder if there are alternatives which aren't just utopian.

Re:White male science

[BrokenHalo]

Fair enough, but where else to look for dark matter but in a dark mine? After all, everybody knows night is caused by accretions of black air... :-P

Re:White male science

[garompeta]

My social studies professor would say that "black" matter is implicitly racist!

Re:White male science

[The Wild Norseman]

My social studies professor would say that "black" matter is implicitly racist!

Would "nutrino-American" matter sound better?

Re:White male science

[Feminist-Mom]

You don't believe in me? I'm real! Santa isn't. I don't make all the 49 yo ac comments though.

Re:White male science

[Anonymous Coward]

While the joke stands, strong, I do wonder if there are alternatives which aren't just utopian.

If you're an American like me, you just live through the peak of our power. So live however you want, and lets hope we can afford a strong military for the next few dozen generations.

1:4?

[Burnhard]

As I understand it, the chances of it being some other (extra-solar) particle detected is about 1 in 4. They need a 1:1000 to have a valid argument. Although interesting, I can't help but wonder when the next funding cycle starts.

Re:1:4?

[wanerious]

Their fiendishly clever plan to get more money hopefully flew under the radar of the other standing-room-only particle physicists and cosmologists in attendance at the seminar where the results were announced.

Re:1:4?

[marcosdumay]

No, 1:4 is enough for a good argument. They need 1:1000 or lower to end the argument.

Re:1:4?

[telomerewhythere]

No, you came here for an agrument. "I want to complain."

Re:1:4?

[Anonymous Coward]

The answer to that, of course, is "Fuck you," followed by *plonk!*

Re:1:4?

[bmearns]

Which is exactly what they specified in the article. They're not making any argument, they're reporting on their findings, and very specifically say:

...we can make no claim to have discovered WIMPs

Re:1:4?

[mrtommyb]

They need a 1:1000 to have a valid argument.

Well, the IPCC report into climate change only reported a 9:1 chance of global warming being due to humans. I think most people would agree that climate change being anthropogenic is a valid arguement, even those who sceptical of the science.

Re:1:4?

[Steve Max]

The chance that "nothing" (as in, no dark matter around here) would generate a signal as "big" as they saw (2 events) is 23%. If they had so many events that the chance of "nothing" generating that number of events was under 0.1% (they'd need 5 or more events on this analysis), they would be able to say the "null hypothesis", or the absence of dark matter, was proven wrong. With their current equipment, they can't do that, and now I'm sure this will be the same result when they analyse the full data set. It takes a bigger detector to detect those particles; or, they never existed at all, but then we'd need a bigger detector to know that anyway.

Re:1:4?

[Gilmoure]

The real fun happens at the open bar Christmas party.

Physicists Gone Wild!

Re:1:4?

[eyendall]

Is this an argument or a contradiction?

It's the lack of energy, stupid!

[BadAnalogyGuy]

We exist in space-time. 4 dimensional beings. Everything we know corresponds to these 4 dimensions.

So what happens when you have a gravitational field? Space bends. Time bends. Since everything with mass exerts a gravitational force, everything bends space around itself to a degree.

But movement is another form of energy, and energy is crucial to completing the 4 dimensional universe. Something with no energy means it has no movement. No movement means it must radiate all of its energy as gravitation. In the end, it will lose all of its mass to this gravitational leaching.

So by reducing the temperature of the sensor to half a degree Kelvin, they have reduced the energy level of the sensor to almost nothing. Yes, it interacts with incoming particles, but it also radiates gravitational waves that could be misinterpreted as external particles. In essence, the detector is detecting itself.

Of course, there is a 23% chance I am completely wrong.

Re:It's the lack of energy, stupid!

[garg0yle]

Something with no energy means it has no movement. No movement means it must radiate all of its energy as gravitation.

So, what you're saying is that something with no energy must lose all of its energy as gravitation. Anybody else see a problem with this explanation?

Re:It's the lack of energy, stupid!

[Yvan256]

That must explain why I get the weird feeling that days are somehow getting shorter.

Re:It's the lack of energy, stupid!

[wanerious]

I think the chances of the above being at all *right* is the 3-sigma event they're looking for. :)

Re:It's the lack of energy, stupid!

[Colonel Korn]

So by reducing the temperature of the sensor to half a degree Kelvin, they have reduced the energy level of the sensor to almost nothing. Yes, it interacts with incoming particles, but it also radiates gravitational waves that could be misinterpreted as external particles. In essence, the detector is detecting itself.

Of course, there is a 23% chance I am completely wrong.

There's a 100% chance you're wrong. Gravitational waves can't be absorbed by these detectors in any meaningful way. To notice the effects of even massive gravitational waves you need a huge detector (like LIGO). Also, gravitational waves happen when a gravitational field changes. They propagate this change through the universe. Objects at rest aren't emitting gravitational waves.

If you isolated these sensors from the universe and let them sit for a long time, they wouldn't lose their mass to gravitational radiation - they'd probably sit around until death by baryon decay in 10^33 years.

And no, they're not detecting baryon decay either.

Re:It's the lack of energy, stupid!

[ArcherB]

Something with no energy means it has no movement.

Or no mass.

Re:It's the lack of energy, stupid!

[Anonymous Coward]

It's poorly phrased.

"If it has no movement, it's energy must be expressed otherwise, thus likely as gravitation."

Re:It's the lack of energy, stupid!

[Zarf]

Oh good, I thought the sun was burning out. If the days get longer I'm going to have a big party. I may have to set up some stones in the field out back to keep track of this...

Re:It's the lack of energy, stupid!

[Chris Burke]

"If it has no movement, it's energy must be expressed otherwise, thus likely as gravitation."

Which is still wrong and silly.

When you cool an object, you are extracting heat energy from it and moving it somewhere else. To cool water enough to freeze, something else is going to get hotter. So it's not a matter of "if there's no movement, how is its energy expressed?" -- there simply is less energy to express, and whatever kinetic energy remains in the material (these detectors are not cooled to absolute zero) is expressed as heat.

It's not a mystery. "Cold things emit gravity waves and eventually evaporate" is unnecessary.

Re:It's the lack of energy, stupid!

[mister_playboy]

Technically, days on Earth get longer as the planet's rotation slows over time. A day was around 21 hours long when T. rex roamed the earth.

Re:It's the lack of energy, stupid!

[daveime]

Now THAT explains the Global Warming !

The earth is moving slower, hence those bits exposed to the sun are exposed for longer. Someone call Copenhagen and tell them they can go home.

Re:It's the lack of energy, stupid!

[Creepy]

I believe you're talking about different things - the detector itself vs dark matter.

Lets do some armchair physics, since I need to dumb it down to my level anyway (I've got a minor in physics...). The known factors of (theoretical) dark matter is it has gravity but does not emit or reflect energy as heat or light, and the reason we think it exists is because galaxies aren't spiraling apart fast enough given the amount of visible matter. I won't pretend to understand that, I'll take it as a given and that the real physicists know what they're talking about.

    Now imagine you put up a "wall" and throw particles at it. When a visible particle hits the wall, it bounces off and release some energy such as heat, just like when you toss a ball at the garage door - it may not be much, but it certainly is there. Now say we throw a dark matter particle at that same wall - what form of energy would it release, assuming it doesn't retain all energy (perfect reflection)? Personally, I don't know, but gravity doesn't sound like a bad suggestion.

Re:It's the lack of energy, stupid!

[Looce]

If the day is longer, the night is also longer. You get warmer days, but then you get colder nights.

Re:It's the lack of energy, stupid!

[daveime]

That's okay, because after that embarassing "Global Cooling" scare in the 70's and then the "Global Warming" that doesn't actually warm us and makes winters worse than ever, we now call it "Climate Change" to cover ALL our bases, and stop Michael Fish looking silly after he fails to predict hurricanes etc.

Funny that weather is always "Theres a chance of changeable weather with sunny periods and frequent showers" ... nothing is ever dealt with in absolutes.

But AGW is always "it's going to happen, we are certain, 110% certain, as certain as a certain thing can be if you feed it certain for a week and make sure it's pooping certain regularly".

Re:It's the lack of energy, stupid!

[Chris Burke]

I believe you're talking about different things - the detector itself vs dark matter.

The OP was talking about the detector. He was saying that dark matter doesn't exist, and the detector was detecting itself giving of gravitational energy. Because it's cold, and must thus be emitting energy as something other than heat. This is nonsense. It just has less energy.

The known factors of (theoretical) dark matter is it has gravity but does not emit or reflect energy as heat or light. [snip] Now say we throw a dark matter particle at that same wall - what form of energy would it release, assuming it doesn't retain all energy (perfect reflection)?

Heat is basically just kinetic energy, which WIMPs are certainly theorized to have what with having both masses and velocities. They are supposed to not interact electromagnetically (so no light), but do interact via the weak force. So... The answer to what happens when it is shot at a wall is usually absolutely nothing as it passes through the wall and the planet the wall is on without interacting with anything. Otherwise, I'd wager it transmits energy via the weak interaction, with gravity being a distant contributor.

Teh problem wif dark mattr

[davidwr]

Dark mattr iz invisable!

Only ceilin cat can c it.

--
Today's lame post brought to you by Teh Lolcat Transzlator.

Dark matter @ Home.org

[MindPrison]

Bring it on!

Re:Dark matter @ Home.org

[Deanalator]

Wouldn't this be something like Yeti@Home?

Re:Dark matter @ Home.org

[BrokenHalo]

I guess that might depend on whether your yetis are house-trained...

Re:Dark matter @ Home.org

[Roger W Moore]

If Dark Matter exists you already have some at home, probably a lot more than you expect in fact!

Meanwhile, Rome burns

[Gothmolly]

So the country is 1.8 trillion (US) in the hole this year, yet someone, somewhere, is funding research half a mile underground, with superconductors, to find particles that might not exist, and if they do, don't mean anything?
How do I get out of this chicken-shit outfit?

Re:Meanwhile, Rome burns

[Fizzol]

The country that falls behind in basic research is the country that falls behind in history.

Re:Meanwhile, Rome burns

[maxume]

There haven't been any reports of success, but fire is rumored to work pretty well.

Re:Meanwhile, Rome burns

[Anonymous Coward]

You're absolutely right. If only we took an extremely short-sighted view of everything, things would be better today. Who cares about tomorrow? The advancement of knowledge is for fictional spacemen in the future, it's not up to us; all we need to do is worry about today. And maybe yesterday. I wish you were running things.

Re:Meanwhile, Rome burns

[mcgrew]

It appears from a quick Google search that the University of Minnesota is funding it. I guess you're against NASA, too, but in favor of pouring trillions down the Iraqui quagmire?

WTF are you doing on slashdot? Trolling?

Re:Meanwhile, Rome burns

[maxume]

Angsting (look at the user name).

Re:Meanwhile, Rome burns

[Anonymous Coward]

Yeah, fuck basic science. I mean, what has scientific research ever done for us? It's just a bunch of eggheads playing with calculators, greedily and selfishly grasping for grant money handouts on the backs of taxpayers. The tiny sliver of the national budget that we invest in science would be much better spent on building another couple of jet-fighters that were designed for Cold War conflicts. Or better yet, it should be be returned to the taxpayers--after all, anything worth doing is also highly profitable. I'm sure the invisible hand of the free market will ensure that we learn exactly as much as we need about the universe, since people are perfectly willing to invest in fundamental scientific research with no guarantee of payoff.
 
If people like you always had your way, we'd still be living in caves suspiciously regarding copper as a useless metal suitable only for decoration.

Re:Meanwhile, Rome burns

[Anonymous Coward]

How do I get out of this chicken-shit outfit?

You can always kill yourself. That'll solve both our problems.

Re:Meanwhile, Rome burns

[Fujisawa Sensei]

So the country is 1.8 trillion (US) in the hole this year, yet someone, somewhere, is funding research half a mile underground, with superconductors, to find particles that might not exist, and if they do, don't mean anything? How do I get out of this chicken-shit outfit?

Just pack up and move elsewhere.

Re:Meanwhile, Rome burns

[GargamelSpaceman]

My gut agrees with you, but I can't say why... Maybe it's the language that falls behind in basic research falls behind in history... If that's the case then funding translation into your language of basic research should be cheaper and have the same effect.

Or else maybe it has to do with having the people doing basic research in your country... I dunno... Maybe the proposition is false or not..

Re:Meanwhile, Rome burns

[Anonymous Coward]

OMG. You Teabaggers are so effing mellow-dramatic. Republicans are such sore losers. I don't care if the Democrats are incompetent. I'm never voting for a whiny do-worse-than-nothing Republican again. Maybe if you and your kind stay out of power long enough you'll learn to become more sensible. God I hate the damn democrats but at least they don't sound like you bastards when they lose and act even worse when they win.

Re:Meanwhile, Rome burns

[pwfffff]

So the country is 1.8 trillion (US) in the hole this year, yet someone, somewhere, is sitting on slashdot bitching about inane things.
How do I best communicate to you that not eating or using energy for a year, or two, or ever, would actually do infinitely more for humanity than your comment here?

Re:Meanwhile, Rome burns

[Anonymous Coward]

How do I get out of this chicken-shit outfit?

Move? Die? It doesn't seem that hard to figure out.

Re:Meanwhile, Rome burns

[Anonymous Coward]

Not to defend anyone who is trolling, but your "love it or leave it" mentality isn't useful.

Even bad ideas help move the discussion forward. And if you don't hear what the trolls are saying, you may miss what the general public is thinking.

Also, America, Fuck Yeah!

Re:Meanwhile, Rome burns

[Anonymous Coward]

Nobody gets out of this chicken-shit outfit alive, so do the math, either pay your "fair share" in taxes or punch license plates for $0.28 an hour.

Solar activity

[mseeger]

All detected particles are due to abnormal solar activity.

The detected particles will melt the crust within the next three years. Buy tickets for the arch from me now! Just 1.000.000 Euro each... No checks

CU, Martin

P.S. Guess which movie i watched yesterday :-)

Re:Solar activity

[Thanshin]

P.S. Guess which movie i watched yesterday :-)

Snakes on a plane?

Casablanca?

Dersu Uzala!

Re:Solar activity

[Mattskimo]

Flirt & Squirt 3?

Re:Solar activity

[thijsh]

"How to become a billionaire by 2013"?
Or maybe you try to become rich-for-cheap and downloaded the spanish cam version: "Cómo hacerse rico en el 2013"?

Re:Solar activity

[10Neon]

Screw that, I'll just move to Africa.

Re:Solar activity

[bmearns]

Buy tickets for the arch from me now!

Ark.

Re:Solar activity

[asylumx]

"Third Man In" ?

Re:Solar activity

[ionix5891]

repeat after me

That movie doesnt exist

Re:Solar activity

[mseeger]

I new there was something wrong with my plan. Now i've got 10.000 arches and no buyer....

Re:Solar activity

[mseeger]

Yep, it's all a goverment conspiracy

Re:Solar activity

[Anonymous Coward]

Flirt & Squirt 3?

I'm both intrigued and scared to know what that is.

must .. not .. google .. porn .. titles .. from .. work

Re:Solar activity

[Megatog615]

It's a codename for the new Zune.

Re:Solar activity

[daveime]

10,000 arches (joined together with bricks an stuff), would make a hell of a bridge. And then you could sell that to someone, I'm sure.

Paper pre-print to appear on arxiv

[Anonymous Coward]

The paper pre-print will appear on the arxiv as 0912.3592, but is already available as on the CDMS homepage. Two events or 23% seems a bit low for all the hysteria... Pentaquarks went away after 50 events were discovered at more than 10 different labs...

Re:Paper pre-print to appear on arxiv

[Anonymous Coward]

Pentaquarks went away after 50 events were discovered at more than 10 different labs...

The difference between pentaquarks and this experiment is that CDMS did their analysis blind. That is, they agreed on what a positive signal would look like before they looked at the data. There's much less chance of making a stupid systematic error when you do a blinded analysis. The pentaquark folk went wrong when they did hundreds of cuts on previously gathered data trying to find anomalies. When you look at a bunch of data and pick out blips, the chance that they're random fluctuations instead of real signal is high.

Tours available.

[mpaulsen]

If you're ever in the neighborhood, a tour of the mine and the lab are well worth the visit.

http://maps.google.com/maps?q=Soudan,+mn
http://www.dnr.state.mn.us/state_parks/soudan_underground_mine/index.html
http://www.dnr.state.mn.us/soudan/physics_tour.html

(Generally open June-September -- check before you come.)

yuo Fail It

[Anonymous Coward]

Apple too. No, Users', BigAzz, fatal mistakes, asshole to others QAnd mortifying Erosion of user recent article put having lost 93% if you don't

How to tell?

[hesaigo999ca]

I watched maybe too many star trek episodes, but I thought this dark matter stuff was in outer space and that any item touching it would implode (sort of). I am not a science expert, but would not finding dark matter inside earth's core insinuate that it was partially made of the stuff and that what we know about dark matter makes no sense??? I am sure there are no real dark matter exerts per se, as it is something we never really had contact with, however, what science knows about it to me seems very limited, and for what I do know ....dark matter should not be something we can just mine and tap into, it should be something that has a lot more involvement environmentally then I see here.

Re:How to tell?

[John Hasler]

> I watched maybe too many star trek episodes...

You did.

Re:How to tell?

[Anonymous Coward]

You're mistaking anti-matter for dark matter.

There has been no accounts of a source of anti-matter in deep space as well. As far as we know, the visible universe is all made of normal matter.
But there is a way to produce it. Ask the LHC, they have some in stock.

Re:How to tell?

[ionix5891]

dark matter is for pussies

real romulan men use only red matter

Re:How to tell?

[Locke2005]

You're confusing dark matter with antimatter. It's ok; it doesn't really matter.

Re:How to tell?

[hesaigo999ca]

Really, how would I know, how would you know, you never posted any info about
answering my question. I guess it's easier to just say someone doesn't know,
when we don't know ourselves!!!

Re:How to tell?

[hesaigo999ca]

So what is dark matter then if it isn't anti matter?

Re:How to tell?

[John Hasler]

> So what is dark matter then if it isn't anti matter?

WIMPs.

Re:How to tell?

[bcrowell]

I can't believe this is only up to +1, Funny so far.

Oh come on now.

[Anonymous Coward]

Dark matter != anti-matter. Turn in your geek credentials.

Re:Oh come on now.

[selven]

Antimatter -> explode.

He said implode, which is red matter.

One in two

[SoVeryTired]

I don't understand where they got 23% from. There are two possibilities: either it is dark matter or it isn't. Therefore the probability is 50%.

Re:One in two

[jfengel]

See, suppose there were a million doors...

Re:One in two

[Anonymous Coward]

RTFA you fucking asshole. 23% of EVENTS DETECTED may be this dark matter shit. Fuck you're dumb.

Re:One in two

[Kozar_The_Malignant]

So either the door you open is the right door, or it's not. Therefore, the odds of opening the right door are 1:2 or 50%. You're just not getting this new math.

Re:One in two

[Anonymous Coward]

You did the maths wrong. Either (1) it is dark matter, (2) it isn't, (3) a wizard did it, (4) it was all a dream. This gives a 25% probability that it's dark matter. The extra 2% is due to statistical error.

Re:One in two

[Anonymous Coward]

If we put 1000 monkeys typing in a cave, we should get Shakespear sometime soon too.

Re:One in two

[Bananenrepublik]

No, there are the following possibilities
1) both excess events are dark matter events
2) the first excess event is a dark matter event, the second isn't
3) the first excess event is not a dark matter event, the second is
4) both excess events aren't actually dark matter events

Hence, in one out of four cases there is no dark matter which gives their 23% after subtracting 2% since we actually know that there is dark matter.

Re:One in two

[John Hasler]

There are two possibilities: either the Earth is flat or it isn't. Therefore the probability is 50%.

Re:One in two

[daveime]

And what about the events that they DIDN'T detect ? Just because they weren't detected doesn't mean they didn't happen, the scientists might have had their backs turned, or were looking the other way, or trying to find the spare detector batteries etc.

Perhaps dark matter deliberately avoids being detected, and the 23% that were could have been the one who didn't get the memo about "being dark", and were wearing spotted ties and green dinner jackets. Oh, and riding Segways.

In a universe of infinite possibilities, only one thing is certain. You need to get your anger issues sorted out, and drink less coffee. No, make that two things. I need to learn to stop posting at 3.22am when I should be asleep.

Re:One in two

[dcollins]

"There are two possibilities: either it is dark matter or it isn't. Therefore the probability is 50%."

Hidden assumption of equally likely events.

Re:One in two

[Anonymous Coward]

No, the probability is not 50%. That logic says you also have a 50% chance of winning the lottery, since there are only two possibilities: either you win or you don't.

The sum of proabilities has to add up to 100%, but nothing says the individual probabilities have to be the same.

1 Hundredth of a Degree Kevin

[sexconker]

That's dangerously low!

My home town nearly went to zero Kevins back in 1978.

It was a particularly cold winter, and we were already down to 3 Kevins (due to their low popularity at the time).

Kevin Thomas had flown out to be with his son's family for a wedding and got stuck in Boston for a whole week due to the weather. 2 Kevins left.

Kevin Lemmer was rushed to the hospital during my shift. I still remember the call from the EMTs as the ambulance was rushing toward us. "It's Lemmer. He's in bad shape. Drove right into the fucking ditch." We called the time of death at 6:15 PM.

At 6:16, all eyes turned to room 2217. Kevin Spencer was 82 and on his death bed with leukemia. His family being Catholic, he had already been given his last rights. If he couldn't hold out until Kevin Thomas returned, we would be at zero Kevins. Sure, we had 4 perfectly healthy Calvins, but they're just not the same.

It was 7:15 when Carla Brooks and her husband James burst through the main entrance. "She's not due for 2 weeks!", James exclaimed. As the staff bustled around getting the Brookses settled, they exchanged darting glances with each other. This was their first child, and they wanted to keep the baby's sex a secret. Of course, in a small town, secrets don't get kept. Nearly all of the hospital staff new that the child about to rip open Mrs. Brooks was indeed a boy.

The delivery was routine, and Kevin Brooks was born healthy, if a tad underweight, at 10:52 PM. Kevin Spencer was pronounced dead at 10:54.

It was, as they say, a close one. Kevin Thomas arrived two days later, the weather having finally cleared up. To this day, we still rib him about it.

Cedar Falls is currently at 5 Kevins.

Re:1 Hundredth of a Degree Kevin

[citab]

Funny +5

Re:1 Hundredth of a Degree Kevin

[bobbozzo]

But everyone has Six Degrees of Kevin Bacon!

Supersymmetry lives?

[SloWave]

If they have really found neutralinos then wouldn't that would mean supersymmetry is confirmed? It that case it is a whole new ballgame in particle physics. There are blogs out there that are saying that CERN is about to announce something big too.

Re:Supersymmetry lives?

[Chris Burke]

If they have really found neutralinos then wouldn't that would mean supersymmetry is confirmed? It that case it is a whole new ballgame in particle physics.

Pretty much. It would really only be a confirmation of one prediction of supersymetry, but it's a pretty damn impressive prediction to see born out, and smart money would be on the other particles predicted to eventually be discovered.

The only sad thing is that to really nail down the evidence for the neutralino will probably take years at CDMS. Oh well, such is cutting edge physics and detecting things that by their nature are extremely hard to detect.

Something is coming out of CERN? That could be exciting.

It's an awesome time to be alive.

Re:Supersymmetry lives?

[Parlyne]

Even if the data were strong enough to claim that they had definitely seen something not reasonably attributable to background events (which it isn't), these results would have very little bearing on the confirmation of SUSY. Even if the results were completely consistent with the expectations for neutralinos, there are dozens of other non-SUSY models which also predict dark matter; and, many of those have regions of parameter space that would be consistent with the very same dark matter detection results.

Re:Supersymmetry lives?

[bcrowell]

If they have really found neutralinos then wouldn't that would mean supersymmetry is confirmed? It that case it is a whole new ballgame in particle physics.

What would the experimental signature of a neutralino be, as opposed to any other WIMP? Comparing the WP neutralino article to the arxiv paper, the mass range does seem to match up roughly, but that's about all I see that would help.

Mod down

[mister_playboy]

Copypasta

http://hardware.slashdot.org/comments.pl?sid=1429380&cid=29967482

http://tech.slashdot.org/comments.pl?sid=1462774&cid=30288116

Re:Mod down

[sexconker]

It's MY copypasta.
I wrote it.
I'll copypasta it whenever I see "Kelvin" used.

Re:Mod down

[thepotoo]

Who cares, that's the funniest thing I've read in weeks.

No wonder people here hate psychology on Slashdot

[Bragador]

Wow, you'd never be able to study large and varied populations then. You do have to understand that probabilities can bring a lot of useful hints as to how you should react after that. If you know that young men have 80% (made up) chance of shutting their brain down when they listen to a beautiful woman, you'd be able to decide to use females in you TV ads to sell your beer to males. Statistics in science can be VERY useful. And it's still science. If you start to break down your groups until you always get 100%, you'll never make it. Even individuals never always act in the same way. You can discover how they react most of the time though...

I detected some dark matter

[SnarfQuest]

I detected some dark matter, but five minutes with a plunger cleared it up.

No longer dark?

[mooingyak]

If we can detect it, does that mean we have to stop calling it dark matter?

Re:No longer dark?

[John Hasler]

No. The name has to do with the fact that it does not interact electromagnetically.

Re:No longer dark?

[Anonymous Coward]

Well, it's not exactly beaming with light and color... and grey matter is taken.

Re:No longer dark?

[marcosdumay]

Probably, with enough confidence astronomers will start talking about neutralino clouds, or something like that.

Re:No longer dark?

[mooingyak]

Neutralino really sounds like the perfect name for a Hispanic Ferengi.

Re:No longer dark?

[IICV]

If you can feel the shape of a dark statue in a dark room with your hands, does it stop being dark?

No? Then no.

Another hypothesis ,mutual backscratching,

[Anonymous Coward]

How could one explain big bang theory that the entire universe coming out of a single infinitesimal point. what fart physicists want us to believe!!
First they said ether..
now they say dark energy...
could somebody tell me what is space-time continuum: position of a particle at a certain time.... i am in restroom at 6:00am and eating lunch in cafe at 12:30 pm... why do we need space time continuum... kimshitty

Mod up

[Anonymous Coward]

It's MY copypasta.
I wrote it.
I'll copypasta it whenever I see "sexconker" used.

Although I generally believe that the less said about sexconker, the better, I do feel obligated to say a few things about sexconker's scabrous maneuvers. First off, sexconker is the embodiment of everything petty in our lives. Every grievance, every envy, every tasteless ideology finds expression in sexconker. While you or I might find it natural to want to deliver him from his appalling ignorance, we must fight for what is right. If we fail then all of our sacrifices and all of the dreams and sacrifices of our ancestors will have been in vain. The key is to realize that even if one isn't completely conversant with current events, the evidence overwhelmingly indicates that sexconker's prognoses are silly to the core. If you don't believe me, see for yourself.

It is as if we were safely on the bank of a raging river, enjoying a picnic with our friends and family, when a bunch of lewd vulgarians came along and threw us into the river. Not only must we struggle to avoid drowning in the raging torrent of sexconker-sponsored mysticism, but we must crawl out of the river before we can call your attention to the problem of bumptious thieves. He is completely mistaken if he believes that all it takes to start a rabbit farm is a magician's magic hat. I would undoubtedly not have thought it possible that we must act against injustice, whether it concerns drunk driving, domestic violence, or even cannibalism, in such a way that there is nothing he can do about it except learn to live with the fait accompli, but it's true. Right is right and wrong is wrong. However true that is, people used to think I was exaggerating whenever I said that sexconker's love of demagogism and irrationalism gives a new, perverse dimension to the old adage, De gustibus non est disputandum. After seeing sexconker toss sops to the egos of the aberrant these same people now realize that I wasn't exaggerating at all. In fact, they even realize that if we set the record straight then the sea of sadism, on which sexconker so heavily relies, will begin to dry up.

Okay, I admit that sexconker's equivocations are made of the same spirit that accounts for the majority of the problems we face in this world. But sexconker says that all any child needs is a big dose of television every day. Yet he also wants to condone universal oppression. Am I the only one who sees the irony there? I ask because he is known for walking into crowded rooms and telling everyone there that superstition is no less credible than proven scientific principles. Try, if you can, to concoct a statement better calculated to show how lawless sexconker is. You can't do it. Not only that, but I am tired of hearing or reading that everything is happy and fine and good. You know that that is simply not true.

Who is sexconker to say that censorship could benefit us? Imagine people everywhere embracing his claim that he values our perspectives. The idea defies the imagination. In order to look at our situation realistically and from a viewpoint that takes in the whole picture we must put to rest the animosities that have kept various groups of people from enjoying anything other than superficial unity. And that's just the first step. Remember, if sexconker would abandon his name-calling and false dichotomies it would be much easier for me to force sexconker into early retirement.

This is not wild speculation. This is not a conspiracy theory. This is documented fact. The tone of sexconker's statements is so far removed from reality I find myself questioning what color the sky must be in sexconker's world. sexconker's irresponsible bons mots oppose the visceral views of 98 percent of the nation's citizens. News of this deviousness must spread like wildfire if we are ever to rally good-hearted people to the side of our cause. Does anybody else feel the way I do, or am I alone in my disgust with sexconker?

Re:Mod up

[selven]

The important question is... does the copypasta taste good?

Particle Statistics

[Roger W Moore]

The only comment I have to make in the other direction is that I am uncomfortable with the probabilities that scientists have suddenly started to give - "there's a 77% chance we are completely correct".

That is not what they are saying. They are really saying "IF we are correct there is a 23% chance that this is just a background fluctuation.". In particle physics we usually have two unofficial rules regarding results. If you have a 3 sigma effect (~1% chance of it being background) then you can claim "evidence for ...." and if you have a 5 sigma variation you can claim discovery. This is because it is REALLY easy to make mistakes in a complex analysis and underestimate or be unaware of other possible sources of background. The large safety factors in the unofficial scheme protect us from making ourselves look like idiots when we get something wrong because it is unlikely (but not unheard of) to get something wrong by such a large amount.

The CDMS result is barely over 1 sigma in significance and so is really nothing at all. In fact if you read their arXiv paper they present the result as a non-observation and put limits on the Dark Matter signal which is the honest thing to do. However they clearly have a clever PR machine which has managed to persuade the media that it is something worthy of reporting.

Relativity...

[Roger W Moore]

Something with no energy means it has no movement.

Or no mass.

You mean "AND no mass.": E^2=m^2c^4+p^2c^2 so both mass and momentum must be zero for zero energy.

You want abuse...

[Anonymous Coward]

That's room 12A, down the hall

No Dark Matter, No Maybe

[Anonymous Coward]

No Dark Matter, No Maybe

A. From "Experiment detects particles of dark matter, maybe"
http://www.sciencenews.org/view/generic/id/50960/title/Experiment_detects_particles_of_dark_matter%2C_maybe
Events in underground experiment too few for certainty, but match the signature of WIMPs.

- "...dark matter — the proposed invisible material believed to account for about 80 percent of the mass of the universe."

- "...tiny vibrations imparted by a proposed type of dark matter called weakly interacting massive particles, or WIMPs."

- "proof of dark matter, Hogan says, would be a huge transformation in how we do science; we would have a new form of matter to study."

- "WIMP fingerprints might be detected by a slew of experiments on the ground and in space including collisions of high-energy protons at the world’s most powerful atom smasher, the Large Hadron Collider near Geneva. Physicists using the LHC, which has now resumed operation after a year of repairs, plan to look for what would be missing: a deficit of energy in the collision debris could be evidence for dark matter particles."

B. Respectfully and tired of, I refrain from more quotes and just suggest searching "Dov Henis there is no dark matter nor dark energy"

Enough is enough. Humanity has been hallucinating about dark energy and matter for circa 100 years.

See:
- "On Energy, Mass, Gravity, Galaxies Clusters, AND Life"
http://www.the-scientist.com/community/posts/list/184.page#2125

- "Implications Of E=Total[m(1 + D)]"
http://www.the-scientist.com/community/posts/list/180/122.page#3108

- "Cosmic Evolution Simplified"
http://www.the-scientist.com/community/posts/list/240/122.page#4427

Dov Henis
(Comments From The 22nd Century)