Dark Matter Particles May Have Been Detected 156
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).
Re:It must be true! (Score:5, Informative)
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.
Paper pre-print to appear on arxiv (Score:4, Informative)
The paper pre-print will appear on the arxiv as 0912.3592, but is already available as on the CDMS homepage [berkeley.edu]. 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:White male science (Score:2, Informative)
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.
Tours available. (Score:3, Informative)
http://maps.google.com/maps?q=Soudan,+mn [google.com]
http://www.dnr.state.mn.us/state_parks/soudan_underground_mine/index.html [state.mn.us]
http://www.dnr.state.mn.us/soudan/physics_tour.html [state.mn.us]
(Generally open June-September -- check before you come.)
Oh come on now. (Score:4, Informative)
Mod down (Score:4, Informative)
Copypasta
http://hardware.slashdot.org/comments.pl?sid=1429380&cid=29967482 [slashdot.org]
http://tech.slashdot.org/comments.pl?sid=1462774&cid=30288116 [slashdot.org]
Re:Mod down (Score:2, Informative)
It's MY copypasta.
I wrote it.
I'll copypasta it whenever I see "Kelvin" used.