I hate having to be pedantic, but please at least do enough fact-checking to get the name of one of our country's premier scientific institutions right! It's the Fermi National Accelerator Laboratory (FNAL) or Fermilab. There is no such thing as Fermi Labs.
There was some attempt a while back to assign dark matter to things like this, or free-floating black holes, brown dwarf stars, etc. I.e., somewhat exotic (or not) objects composed of normal matter.
However, in the past maybe 10 years, the constraints for dark matter come much more from cosmological arguments than from observations of the galaxy today. If you're interested, I'd suggest googling WMAP and baryon acoustic oscillations. The basic idea is that we can study the cosmic microwave background, which is the left over radiation as the universe cooled below a critical point some few 100k years after the big bang. In the CMB are embedded small fluctuations like ripples in a pond after you throw rocks in, which are the imprint of pressure waves spreading outward through the primordial plasma. By studying the size and spacing of these ripples, and applying a whole crapton of cool math, you can deduce things like the speed at which those ripples propagate, which is a direct function of both the total matter density and the baryonic (i.e. normal) matter density.
Of course I'm skipping all the details, but the basic result is that, although we first noticed dark matter from observing the motion of galaxies today, it was confirmed to a much better degree by observing the universe in its birth stages, and it's these latter measurements that tell us that dark matter absolutely cannot be due to the behavior of matter and general relativity as we understand it today.
Very few collaborations of this size release all of their data publicly. Partly it's a practicality issue: how do you share several TB of data with whoever wants it? Plus, it's very easy for someone not familiar with the setup to misinterpret the data (an argument often used by climate scientists for why raw data is not released).
As I said, I don't think anyone disputes that DAMA sees _something_ with an annular modulation,just their interpretation of it. As far as the community is concerned, the WIMP explanation HAS been falsified already. But the DAMA people hold out that, since the other detectors use different target materials they are not directly comparable. Stalemate until someone else can get ahold of some of their crystals.
The most often-cited hypothesis are cosmic rays, which do show a similar annular modulation due primarily (as far as we know) to changing temperature and density in the atmosphere. This modulation is measured extremely well by MACRO, a detector in LNGS (the same site as DAMA). But, the phase (time of year when the signal is at maximum) of the cosmic ray modulation seems to be inconsistent with the DAMA (and to a lesser extent, CoGeNT) oscillation.
WIMPs are also not a particularly defined particle; only the "vanilla" WIMP is excluded by CDMS and Xenon. Every theorist has his or her favorite way to reconcile all the experimental evidence, usually by just changing one or two parameters. For instance, you can make the Xenon signal agree by proposing that the WIMP interacts differently with neutrons than with protons, which is actually well-supported by some models. The thing that NO theory can do is reconcile the CoGeNT and CDMS signals, since they are both germanium detectors; those two will be where the interesting showdown happens I think.
There's a huge controversy right now in the field. The DAMA/Libra experiment has been claiming an 8-sigma excess for years which they say is consistent with dark matter, but they keep getting excluded by other experiments, most notably CDMS and Xenon. Every time their favored region is excluded, they come up with a new way to reanalyze their data to make it consistent again. But they have not ever released any of their data to the community (and hold patents on the type of crystal they use for their detector) so it's impossible to directly verify.
CoGeNT first released hints of a low-energy excess which could be consistent with DAMA-type dark matter about a year ago. I was at the APS conference earlier this week where Collar released the seasonal modulation results which make it seem even more likely that they see the same thing as DAMA. However, just the next day, CDMS presented an analysis of their low energy data which is below their normal dark matter threshold (because the rate of background events in that region is quite high and poorly understood). They showed that, even if they didn't account for the known sources of background, the rate in their detector is inconsistent with CoGeNT's. As many people rightly point out, CoGeNT is seeing an exponential signal near threshold, which is what you'd expect to see in just about any detector with or without dark matter present.
The whole situation is muddled even further by politics and personalities. Collar is respected as a scientist, but is also generally agreed to be an asshole. When he announced the annular modulation result, he spent 25 minutes of his talk attacking xenon on mostly pointless grounds, then had only a single slide showing the important result of the modulation. He finds tiny holes in other's analyses, but doesn't often present a very convincing picture of his own.
tl;dr: The community is far from agreeing that what he and DAMA have seen are in fact WIMPs. CDMS and Xenon tend to have better established analysis programs and pay more attention to their systematics, and they still rule out both DAMA and CoGeNT. However, I think everyone at this point agrees they are seeing something interesting, just likely not WIMPs.
There may be bugs in the Android DHCP, and who knows what else, but I think this is much more likely just typical crappiness of Princeton's IT department. As a grad student here, I've encountered a huge number of examples. I've had at least 3 devices banned from the network because they did "improper" things. Most were genuinely misbehaving (like a crappy router that spilled the occasional 192.168.. address onto the WAN), but not to such a terrible degree that they shouldn't have been handled.
Want to run gentoo? The network flat out won't respond to DHCP queries. Own a Wii? Can't connect to the wireless net because of some technical issue Princeton hasn't bothered to fix for over 2 years.
Forgive me if I'm skeptical of the severity of the Android issue knowing how awesomely capable our IT department is.
Yes, but the arxiv is filled with all sorts of gibberish submissions as well. It is a wonderful and very useful repository, but just assuring that a paper is placed there doesn't mean that those wanting to access those papers will be able to dig through the mess to find it.
But the worst part is that absolutely no warning is given when submitting info on a completely unencrypted page. So the message is that somehow encryption via self-signed certificates is worse than just no encryption at all.
We get all these retarded warnings about "You are viewing an encrypted page, but some of the information is not encrypted! Oh noes!" But how freaking hard is it to pop up a warning on any form you try to submit that's unencrypted? Or if you think that would be too annoying, any form that includes a password field?
Although it's quite possible for your time to be valued $0/hr, as is the case if you enjoy mucking about in the guts of a computer until you get a beautiful arrangement. Let's face it, if you're running some BSD/*nix, you like to fiddle with shit.
make sure you get the extended warranty then - I've had to replace the battery, hard drive, dvd player, and screen of my macbook, and this thing doesn't even get used when I'm not travelling.
I second that one wholeheartedly. The GUI admin, which is billed as this "any average Joe can run a network" (which is how I got stuck with it with no training) is completely inadequate if you're doing anything completely non-trivial, but thinks it know better than you and clobbers any edits you make to the config files.
Also, the DHCP and NAT fail tremendously. I told the server to serve DHCP and provide NAT services to the subnet so that my cluster would have one forward facing IP address. This worked great until someone unplugged the LAN cable, leaving the WAN as the only living connection. Since I had NAT on, OSX Server decided I must really want it, and just made a mistake for what side I wanted it on. So it happily started serving up DHCP requests on the wider network, at least until OIT hunted it down and screamed at me.
...I am incredibly disheartened by the number of people using terrible grammar and spelling in order to bemoan the anti-intellectualism of our society.
Even outside purely academic circles, there are plenty of real world effects. If I develop a drug which causes blindness but I falsify my data to show that it in fact cures cancer, and some company markets this drug based on my research, you will certainly see an effect. Of course, this is an extreme example, but similar results apply for most levels of falsification.
Time does have a preferred direction even at the quantum level, as evidence by CP Violations - it's one of the reasons that antimatter is so rare in the universe.
The entanglement usually occurs to conserve some physical quantity, such as spin or momentum. So for the dice example, let's say that every pair of entangled dice must add up to 7.
The problem is that they can only become entangled while they're still in luminal communication range - so you have to roll all the dice before the ship leaves.
If neither of you looks at your dice, then the number rolled remains undefined. As soon as one of you looks at a given die, both it and it's twin instantly take on their respective values (or you spawn 6 universes identical in every way except for the values rolled, if you like the multi-universe theory.) But when you look at a die, all you see is a number. You know that the number on the previously entangled die must be 7-#, but you have no way to tell whether you looked first or your counterpart on the ship.
Slashdot Mirror
I hate having to be pedantic, but please at least do enough fact-checking to get the name of one of our country's premier scientific institutions right! It's the Fermi National Accelerator Laboratory (FNAL) or Fermilab. There is no such thing as Fermi Labs.
There was some attempt a while back to assign dark matter to things like this, or free-floating black holes, brown dwarf stars, etc. I.e., somewhat exotic (or not) objects composed of normal matter.
However, in the past maybe 10 years, the constraints for dark matter come much more from cosmological arguments than from observations of the galaxy today. If you're interested, I'd suggest googling WMAP and baryon acoustic oscillations. The basic idea is that we can study the cosmic microwave background, which is the left over radiation as the universe cooled below a critical point some few 100k years after the big bang. In the CMB are embedded small fluctuations like ripples in a pond after you throw rocks in, which are the imprint of pressure waves spreading outward through the primordial plasma. By studying the size and spacing of these ripples, and applying a whole crapton of cool math, you can deduce things like the speed at which those ripples propagate, which is a direct function of both the total matter density and the baryonic (i.e. normal) matter density.
Of course I'm skipping all the details, but the basic result is that, although we first noticed dark matter from observing the motion of galaxies today, it was confirmed to a much better degree by observing the universe in its birth stages, and it's these latter measurements that tell us that dark matter absolutely cannot be due to the behavior of matter and general relativity as we understand it today.
Very few collaborations of this size release all of their data publicly. Partly it's a practicality issue: how do you share several TB of data with whoever wants it? Plus, it's very easy for someone not familiar with the setup to misinterpret the data (an argument often used by climate scientists for why raw data is not released).
As I said, I don't think anyone disputes that DAMA sees _something_ with an annular modulation,just their interpretation of it. As far as the community is concerned, the WIMP explanation HAS been falsified already. But the DAMA people hold out that, since the other detectors use different target materials they are not directly comparable. Stalemate until someone else can get ahold of some of their crystals.
The most often-cited hypothesis are cosmic rays, which do show a similar annular modulation due primarily (as far as we know) to changing temperature and density in the atmosphere. This modulation is measured extremely well by MACRO, a detector in LNGS (the same site as DAMA). But, the phase (time of year when the signal is at maximum) of the cosmic ray modulation seems to be inconsistent with the DAMA (and to a lesser extent, CoGeNT) oscillation.
WIMPs are also not a particularly defined particle; only the "vanilla" WIMP is excluded by CDMS and Xenon. Every theorist has his or her favorite way to reconcile all the experimental evidence, usually by just changing one or two parameters. For instance, you can make the Xenon signal agree by proposing that the WIMP interacts differently with neutrons than with protons, which is actually well-supported by some models. The thing that NO theory can do is reconcile the CoGeNT and CDMS signals, since they are both germanium detectors; those two will be where the interesting showdown happens I think.
There's a huge controversy right now in the field. The DAMA/Libra experiment has been claiming an 8-sigma excess for years which they say is consistent with dark matter, but they keep getting excluded by other experiments, most notably CDMS and Xenon. Every time their favored region is excluded, they come up with a new way to reanalyze their data to make it consistent again. But they have not ever released any of their data to the community (and hold patents on the type of crystal they use for their detector) so it's impossible to directly verify.
CoGeNT first released hints of a low-energy excess which could be consistent with DAMA-type dark matter about a year ago. I was at the APS conference earlier this week where Collar released the seasonal modulation results which make it seem even more likely that they see the same thing as DAMA. However, just the next day, CDMS presented an analysis of their low energy data which is below their normal dark matter threshold (because the rate of background events in that region is quite high and poorly understood). They showed that, even if they didn't account for the known sources of background, the rate in their detector is inconsistent with CoGeNT's. As many people rightly point out, CoGeNT is seeing an exponential signal near threshold, which is what you'd expect to see in just about any detector with or without dark matter present.
The whole situation is muddled even further by politics and personalities. Collar is respected as a scientist, but is also generally agreed to be an asshole. When he announced the annular modulation result, he spent 25 minutes of his talk attacking xenon on mostly pointless grounds, then had only a single slide showing the important result of the modulation. He finds tiny holes in other's analyses, but doesn't often present a very convincing picture of his own.
tl;dr: The community is far from agreeing that what he and DAMA have seen are in fact WIMPs. CDMS and Xenon tend to have better established analysis programs and pay more attention to their systematics, and they still rule out both DAMA and CoGeNT. However, I think everyone at this point agrees they are seeing something interesting, just likely not WIMPs.
knowledge in improving our understanding of the universe ... So it's not science for the sake of science.
Ummm, methinks you should look up the definition of science
There may be bugs in the Android DHCP, and who knows what else, but I think this is much more likely just typical crappiness of Princeton's IT department. As a grad student here, I've encountered a huge number of examples. I've had at least 3 devices banned from the network because they did "improper" things. Most were genuinely misbehaving (like a crappy router that spilled the occasional 192.168.. address onto the WAN), but not to such a terrible degree that they shouldn't have been handled.
Want to run gentoo? The network flat out won't respond to DHCP queries. Own a Wii? Can't connect to the wireless net because of some technical issue Princeton hasn't bothered to fix for over 2 years.
Forgive me if I'm skeptical of the severity of the Android issue knowing how awesomely capable our IT department is.
Fortunately, these machines are not in use any more
Not sure where you got that piece of info, but they were using them in Chicago yesterday...
And this is "unfortunate" why, exactly?
It's disturbing that this is modded "interesting" rather than funny...
Yes, but the arxiv is filled with all sorts of gibberish submissions as well. It is a wonderful and very useful repository, but just assuring that a paper is placed there doesn't mean that those wanting to access those papers will be able to dig through the mess to find it.
But the worst part is that absolutely no warning is given when submitting info on a completely unencrypted page. So the message is that somehow encryption via self-signed certificates is worse than just no encryption at all.
We get all these retarded warnings about "You are viewing an encrypted page, but some of the information is not encrypted! Oh noes!" But how freaking hard is it to pop up a warning on any form you try to submit that's unencrypted? Or if you think that would be too annoying, any form that includes a password field?
Although it's quite possible for your time to be valued $0/hr, as is the case if you enjoy mucking about in the guts of a computer until you get a beautiful arrangement. Let's face it, if you're running some BSD/*nix, you like to fiddle with shit.
make sure you get the extended warranty then - I've had to replace the battery, hard drive, dvd player, and screen of my macbook, and this thing doesn't even get used when I'm not travelling.
I second that one wholeheartedly. The GUI admin, which is billed as this "any average Joe can run a network" (which is how I got stuck with it with no training) is completely inadequate if you're doing anything completely non-trivial, but thinks it know better than you and clobbers any edits you make to the config files.
Also, the DHCP and NAT fail tremendously. I told the server to serve DHCP and provide NAT services to the subnet so that my cluster would have one forward facing IP address. This worked great until someone unplugged the LAN cable, leaving the WAN as the only living connection. Since I had NAT on, OSX Server decided I must really want it, and just made a mistake for what side I wanted it on. So it happily started serving up DHCP requests on the wider network, at least until OIT hunted it down and screamed at me.
it just works my ass
...I am incredibly disheartened by the number of people using terrible grammar and spelling in order to bemoan the anti-intellectualism of our society.
Too bad apple's X11 is broken all to hell
Even outside purely academic circles, there are plenty of real world effects. If I develop a drug which causes blindness but I falsify my data to show that it in fact cures cancer, and some company markets this drug based on my research, you will certainly see an effect. Of course, this is an extreme example, but similar results apply for most levels of falsification.
using this would be cheaper by half.
not to mention the extra geek cred that this solution gets you.
I've been trying to come up with a way to install a webcam somewhere in the department lounge so I can be the first to know when free food shows up...
Hear hear!
A government too weak to pass any laws but those that are blindingly, obviously necessary is my kind of government.
Anyone know where I can get one of those?
Unfortunately, virii would be the plural of 'virius' (which, if it were a word, would mean something along the lines of 'manly'). =)
I worked on NOvA R&D years ago as an undergrad research project. It's been under construction already for several years now...
Time does have a preferred direction even at the quantum level, as evidence by CP Violations - it's one of the reasons that antimatter is so rare in the universe.
The entanglement usually occurs to conserve some physical quantity, such as spin or momentum. So for the dice example, let's say that every pair of entangled dice must add up to 7.
The problem is that they can only become entangled while they're still in luminal communication range - so you have to roll all the dice before the ship leaves.
If neither of you looks at your dice, then the number rolled remains undefined. As soon as one of you looks at a given die, both it and it's twin instantly take on their respective values (or you spawn 6 universes identical in every way except for the values rolled, if you like the multi-universe theory.) But when you look at a die, all you see is a number. You know that the number on the previously entangled die must be 7-#, but you have no way to tell whether you looked first or your counterpart on the ship.