CelticRose
Graduate Poster
Two whole particles? I don't think I'm going to get too excited just yet. Wake me when someone's confirmed the results.
Dark matter detected?
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Not to mention coming about naturally from beta decay.
The preprint is now available on the CDMS web page. It has an ArXiV number, which presumably means it'll be on the server soon.
It's only two events, true, but they're very nice looking events. Not just hanging out a bit past the edge of a noise distribution---they're really unique-looking, distinctive hits.
It's obviously the neutralino from a MSSM with m_1/2 = 400, m_0 = 90, and tan beta = 10, and mu > 0. Next question?
Dancing David
Penultimate Amazing
Science by press release.
You know Zeuzzz, your point is an example of false equivalence, you know it, go peddle your delusions somewhere else.
You and others used the 'science by press release' critique of mainstream science.
So where is the hyperbole, where is the overstatement, where is the equivalence?
This is as bogus as your take on statistical reference. (Arp's use of statistics was wrong, just as the critiques of press releases as mainstream science was wrong.)
Dancing David
Penultimate Amazing
Not under the usage here, they reflect and generate EM energy. So while they do not shine they are visible by conventional means. Take Jupiter or Neptune, they both have an appreciable radio frequency emission. They also reflect and interact with photons through the EM force.
Dark matter is hypothesized to be particles with mass that interact through the weak force and gravity, they are like nutrinos in that way.
learner
Graduate Poster
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Very dark Im betting. It was half a mile underground
Seriously, im going to do some googling, Im aware of dark matter but know next to nothing about it. Sounds very interesting.
Any directions to sites or advise for a dullard wanting an easy explanation would be appreciated.
Thanks
MattusMaximus
Intellectual Gladiator
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Exactly. We have to wait for more verification & confirming evidence before we break out the champagne.
Supposedly WIMPS.
kalen
Your Daddy
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I thought particle physicists standards were a little higher - 5 sigma effects are usually good enough for a "discovery."
I don't know anything about this experiment, but somewhere along the way they decided that there is no background to this dark matter signal. I'm sure they have good reasons for it. I will definitely be checking this out.
Also, I'm sure it was a hell of a long time before they even got two events - one reason for making an announcement. They'd better see more in the future, though.
Imagine if a Higgs discovery was announced on the basis of two events... (OK, that won't happen - there is a large BG to the Higgs signal, and a large number of events need to be collected to say with statistical certainty that a signal was seen.)
I don't know anything about this experiment, but somewhere along the way they decided that there is no background to this dark matter signal. I'm sure they have good reasons for it. I will definitely be checking this out.
Also, I'm sure it was a hell of a long time before they even got two events - one reason for making an announcement. They'd better see more in the future, though.
Imagine if a Higgs discovery was announced on the basis of two events... (OK, that won't happen - there is a large BG to the Higgs signal, and a large number of events need to be collected to say with statistical certainty that a signal was seen.)
Not at all. They decided (and this is 3/4 of the challenge of such projects) that the expected background was something like 0.8 events. i.e., if they run the experiment 100 times and there is only this background, they'd expect to see zero events in 45 of the runs, 1 event in 36 or the runs, and 2 events in 14 of the runs. I.e., 2-event-signals are rare-ish (but not super rare) if that background is the only thing going on. On the other hand, 2-event-signals are common if there are WIMP interaction events in addition to the background.
Every such experiment runs as long as it can, with as much sensitive target mass as it can afford, then stops and announces what it saw. Most experiments to date have gotten to the budgetary end and announced "we saw zero". Edelweiss announced "we saw one". DAMA announced "we saw this mad crazy weirdness". CDMS is announcing "we saw two".
The analysis was "blind", in that the experimenters were not allowed to look at these two events (nor even to know how many there were) until everything had been pinned down---there was no human intervention of the "let's wait until we have another event" sort.
Your blatant cry for money is ignored! Take that, greedy scientist scum!
Mneh ... I'm sure the check is already in the mail. After all, it is near year's end, and that means less than two weeks to make a donation that is deductable on the (U.S.) income tax.
They woman that taught me how to do 'psychic' readings to me that if there is one thing to rely on it is greed ... and gullibility.
No, make that two things; greed and gullibility ... and arrogance.
Badly Shaved Monkey
Anti-homeopathy illuminati member
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Yes, but...might Bill Thompson be half-remembering what I half remember. "Dark Matter" as an umbrella term actually encompasses quite a range of candidate objects and brown dwarf stars (which Bill's comment about planets would fit with) was one possibility, i.e. boring ordinary matter, but just hard to see, while more exotic things like new classes of weakly interacting particles are another.
The reported experiment only relates to that latter possibility, so the question is, has "Dark Matter" now become synonymous with WIMPs or is hard-to-detect ordinary matter still a live possibility, while fiddling with gravity (MOND) represents a completely different way to explain the observed galactic motions without actually having to invoke invisible mass.
Badly Shaved Monkey
Anti-homeopathy illuminati member
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While I'm asking the idiot questions, can someone please clarify, were all these WIMPs, which seem to end in "-ino" predicted by pre-existing theory, then along came the observations that implied the existence of Dark Matter, so that the -inos could immediately be advanced as candidates. Or was it the other way round, CDM was predicted then a gap in theory was found which -inos could fill and explain the observations. I, as an interested non-physicist, certainly had heard of supersymmetry long before I'd heard of Dark Matter, which suggests that the first was the sequence of events.
shadron
Philosopher
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Hubble (I think it was him, or a contemporary) first conceived of dark matter before WWII. They noticed that galaxy observations were clumping unexpectedly and coined dark matter to explain the gravitation that they were observing. This was not before the BB theory was promulgated, but it was certainly before CMB was predicted or observed, and before almost all of the standard theory of particles was described in the 40s and since. So it was a pair of, or perhaps three, disconnected hypotheses coming together in more recent times.
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I think the name you are probably looking for is Fritz Zwicky.
What shadron said, although its not very important in that they're independent theories. The inferred properties of supersymmetric particles are completely independent of dark matter observations. The fact that many SUSY theories produce a new, stable, uncharged particle that would seem to have properties in agreement with DM observations may be a sign of the nature of WIMPS. Alternatively it could be a complete coincidence.