Did i mention the lack of programs? It has less programs than beos. I heard all these great things about it, then I started using it. And now all i want to do is go back to other OSes. I feel like i'm trying to make a 3 year old build a car or something it can't reasonably do. And its not as crashproof as everyone claims. Its crashes more than the win98 machines.
QNX is designed as a real time OS. It really isn't for consumer apps. It's pretty well regarded for RT work.
Although I'm in opposition to the majority here and will probably get negative moderation for this, I think that Katz is overreacting. There are several problems with Katz's article.
A major fault is that Katz doesn't provide any evidence to support his claims. He cites emails from several principles and administrators but doesn't give us a copy of the report, just a list of characteristics. We're not even sure if the list of characteristics is complete. The url for the halifax paper is link to a bank robber being caught not a "geek profile." In addition I'm curious why a canadian law enforcement agency has the profile and is giving it to canadian papers. Toss in the lack of coverage in other media sources and I'm sceptical as to the validity of the profile.
My other problem with this is that Katz seems to see a lot of the reaction to the Columbine incident as being "anti-Geek." He also seems to believe that profiles aren't necessary. Although, one would ideally want schools to evaluate everyone individually, schools have limited resource so it makes sense to have a profile that selects those most likely to be violent/dangerous/in need of help and focus the resources on those people. In analogy, think about how many system administrator read through system log files every day and how many use logcheck, swatch, etc. to just screen out the important ones based on a profile.
Katz claims that "bullies and predator" that pick on other children aren't singled out but several of the points in the checklist apply Come from dysfunctional homes. Experience unstable self-esteem. Have experience with chronic bullying and drug use. I think the second item is applicable and since most bullies usually have a dysfunctional family file the first one applies. In addition, bullying is often used to bolster a lack of self-esteem so the second item probably also fits. Katz's assertion about teachers is not valid since the profile is supposed to pick out potentially dangerous students. Whether schools/teachers are responsible for this is a valid question but is not importance in the context of a discussion on the merits of the profile.
Katx also goes on to bring in Mosaic-2000. Doing so is irresponsible and does not contribute anything to the article. Given that the details of how the program identifies "dangerous" students and how this program will be used, claiming that this program will select geeks is not very credible.
All in all, I think that Katz is overreacting or delibrately trying to provoke a reaction among the Slashdot community. His evidence is based on heresay, and links that don't check out. The lack of coverage in other media also discredits his article. The widespread coverage that the national media gave to Mosaic-2000 makes their silence on this profile all the more damning.
Assuming that the data is unbiased and representative of the entire population, we still have nothing more that a statistical correlation. And even then, we are unable to determine the strength of this relationship.
Granted the data seems to only imply a correlation but correlations are often useful. While they do not imply that one factor causes the other they do allow one make fairly accurate predictions. For example, the presence of smoke and a fire are strongly correlated so if you see smoke you can usually predict that there is a fire.
If you consider some philosophical stances (e.g. Hume), correlations are the only thing that we have since we can not prove causation for anything. We base science on very strongly correlated things. Nothing tells us the sun will rise in the east tomorrow but we are fairly confident that it will do so tomorrow since it has done so every morning. (For those that claim that physics tells us the sun will rise in the east, what insures that the laws of physics won't change tomorrow?)
Yeah there's a buffer overflow in the software. This is pretty wierd/bad since it's one the only pieces of software that has a security hole put in it on purpose and with a lot of forethought. check out this for more details.
The AOL IM actually has a buffer overflow exploit present. Basically whenever an AOL client connected to the server, the server smashed the stack and executed a piece of code that would send a packet back to the server. This let AOL change the authentication on the fly without updating the client. Of course, it also opened up some security holes. This was discussed on bugtraq in August.
The article indicates that the working theory behind this is that glucose is the thing that really matters. If that's the case then drinking gatorade or eating anything that's high in glucose will have an effect. So its not just potatoes.
The researchers have no clue why barley works so it could be that any food would work. Without more studies I wouldn't go out and eat ten pounds of potatoes the night before an exam.
s this really true? I would think that for the typical modem user, given the sporatic data transfer nature of Web browsing (little happens after the page is locally cached until you go to the next), that a regular phone call moves way more total data over the same period of time.
But the lines still tied up even when there is no traffic. Plus modem users tend to use the line for a lot longer. Most conversations don't last an hour.
The ACLU post is somewhat slanted and gives the advisory a negative spin. If you read the advisory, the FEC says that the valuation needs to consider part of the cost of running computer and website towards the $250 limit.
In this case, the guy running the website needs to determine what part of his costs the advocacy website took up. Then if these costs exceed $250, he needs to register.
The Commission notes that there are minimal costs associated with creating the web site. Some portion of the previous expenses described in your request could be apportioned to each and every web site that you construct as part of your business. These overhead costs would include, for example, the fee to secure the registration of domain name, the amounts you invested in your hardware, and the utility costs to create the site.
Here the FEC seems to indicate that costs for just running the website needs to be considered. For example, if the DNS registration takes 35 a year, then cost needs to be divided by the number of separate DNS names he is using and then the cost for just the names he is using for the website needs to be considered. Also in valuating the cost of the website Leo just needs to consider the cost it took to prepare the site excluding his contribution in time(e.g. if he had to pay x dollars for the rights to use the images on the web site, he needs to include these x dollars in the valuation).
But that wasn't enough for the FEC. In an advisory opinion issued at Smith's request, the FEC said that it determines the value of web sites by counting, among other factors, the cost of the computer hardware and software used to create the site. If the computer cost more than $250, the FEC said, its owner would have to meet the filing and disclosure requirements of federal law.
The ACLU's characterization of the FEC ruling makes it harsher then it seems. If the computer cost over 1000, then the full cost of the computer only needs to be consider if all you do is run the political website on the computer. If all you do is create the website and set it up on a free homepage then you would need to file only if getting the images and processing them cost over $250. Also the FEC advisory seems to have been stricter since Leo was solicting donations for a candiate.
The ACLU seems to have made the ruling more ominous and threatening then it really is in order to drum up support and contributions. However IANAL so I may have interpeted the FEC advisory incorrectly.
Have they redefined basic terms since I had chemistry back in high school? Different sized buckyballs wouldn't be different isotopes (different atomic weights of same element due to different neutron count), or even different isomers (different structures made of same set of atoms), they'd be different molecules. Or did someone sneak crack into my rootbeer?
It gets worse, the original poster was a chemical engineer. Of course he or she probably just had a mental slip up.
2. How much power can be generated per unit area ? I'd like to see the "theoretical maximum" and the actual measure of the current material. This would allow elementary comparisons between solar collector's and chlorophyll. This sounds like a great breakthrough, but exactly how good is it compared to what we have ?
The energy incident on the Earth can be calculated by estimating the energy the sun emits (assume its a 5500K blackbody) and then figuring out how much is incident on a disc of the earth's diameter at ~ 1 AU away. If I remember right, the figure comes out to something like 14 W/m^2 within an order of magnitude. If we achieve the same efficiency plants do we'll be able to get about 30-40% of it in usable form (which is damn good).
What frequencies can the material respond to ? This question could be important to the space program, if materials can be made that convert even a fraction of the radiation from the sun to usable energy there could be a great saving in mission mass requirements ?
You can tailor its frequency response by attaching side groups to the porpyrhin rings or by changing the conjungation of some of the bonds within the rings. Most chlorophyll is most sensitive at about 720nm and 640nm since the sun's energy output peaks there.
Unfortunately this sort of material wouldn't be too effective in space without a lot of shielding. Most organics are fairly fragile and exposing it to the conditions in space would cause it to break down. Add in high energy photons(gamma, UV, x-ray) and the molecules start breaking down quickly.
Although its a greate achievement there is still a lot more to do. To actually use this you need to create a chain to transfer electrons and extract energy from it. Plants do this with photosystems I and II which generate NADPH(?) and ATP. The problem with this is that you get chemical engery out of it when you typically want electrical energy*. Although its possible to convert, you lose a significant fraction of the energy in the conversion. The technology may siimply not be viable if the energy received on a given area is too small.
(*)- Yes I'm aware you could create a system to generate a system that say generates ATP, and then uses the ATP to fuel a reductase or oxidase in order to run an electrolytic cell. This sort of system may work well for biological systems which have power consumptions on the order of 120 W (this is based on energy requirements of 2500 Kcal/day, fyi 1 Calorie in the nutrional sense equals 1000 calories in the biological sense). Photosynthetic systems work great in biology since plants concentrate energy over long periods of time, e.g. it takes 3-4 months to generate the energy required to produce a couple ears of corn.
The trouble is that even the theoretical output of solar cells is low. It's bounded severely by the surface area because of the limitations of the diode materials available to us today. Turns out that even if you have full light shining on the surface, you can only get about 29% efficiency - and that's theoretical. In reality, it's less.
The best efficiencies I've seen so far is about 17% so its not that great. OTOH the efficiencies of combustion engines and power plants are only on the order of about 20-40%. I believe that maximum efficiency possible with Carnot egnine is about 40% with the current temperatures our engines run at.
So much in this article was negative, and I sensed a political agenda in it. Particularly repeated comparisons (of Open Source) to Communism and Socialism, apparently to inspire faulty logic like the following: Open source is like Communism. Communism failed. Therefore, open source is doomed to failure.
I think the author made a clear point about OSS resembling scientific communities rather than Communist/Marxist communities. His main point seemed to be that OSS resembled scientific communities and suffers from the same problems.
The sotry doesn't seem very believable. The most recent reports were of quantum computers able to factor the number 4. Although breakthroughs happen, I doubt that any breakthrough of this magnitude happened. It's sort of like someone suddenly building a pentium III when everyone else was building 8088 or m68ks. In addition the lack of details make the story pretty suspect.
That means that I can get the VHDL description of the device, and drop it into an FPGA or ASIC (field programmable gate array and application specific integratted circuit) and make a single-chip solution to some embedded problem. Who would buy the actual silicon from Zilog?
A FPGA from Xilinx costs about $20. The Z-80 costs a few dollars. Multiply the difference by about 1 million and you see significant savings by using the Z80 from Zilog.
How are they going to filter out the light produced by bioluminescent marine organisms? I thought they were common in the deep ocean.
I believe that the bioluminesence occurs at a wavelength quite different from the cherenkov radiation that the neutrino interactions produce. The neutrino interactions produce radiation at about ~400-500 nm which is right at or above the upper edge of human vision. So you can probably filter out bioluminescence by constructing the appropriate filter or ignoring lower energy photons.
That about wraps it up. I haven't had time to check out the details of this proposal. I'll be interested to see how they plan to get the water sufficiently clear that they can detect the scintillations from the muons. If the water is too murky, then the tiny Cherenkov flashes get absorbed, and you don't get any signal. Perhaps the sea water clears up if you go down deep enough?
It's surprising but some locations in the ocean have water clear enough that the attenuation length is about 200m. For example, the DUMAND site off Hawai'i had water that was about that clear. For comparision 18megaohm (100% pure) water has an attenuation length of about 300m so its not that bad.
In this example, gravity is a force of nature that is thought of in two ways: Strong nuclear force, and Weak nuclear force. These two forces combine to be what we call gravity.
The strong nuclear and weak nuclear force are different from gravitational forces. The strong nuclear force is mediated by gluons or mesons depending on whether it is affecting quarks or hadrons. The weak nuclear force is mediated by W-,W+, and Z0 bosons. The two forces do not combine to form gravity. Gravitons are postulated to mediate gravitational attractions but has not been detected yet.
It is a rare event to actually stop a nutrino, and the chances are slim that you can force it to happen in a lab. So some smart scientist decided one day to use an old abandoned mine under mount fuji in Japan. There is several giga-tons of mountain for nutrinos to go thru untill the poor particle finds itself in a big nutrino trap. hehehehe The equipment is so sensitive that nothing must ever move in its presence, and people are advised to not go near them.
That is totally untrue. I know for a fact that SuperK is located in Toyama near Mizumi. Also its in a aluminum mine. Last I heard Mt. Fuji wasn't being mined. Also the equipment is not that sensitive. People routinely go to the top of the tank to adjust stuff. In addition, the mining company is doing some blasting a couple hundred meters away the control center and tank and this is not affecting the instruments.
I thought it was interesting because scientists theorize that the "missing" mass associated with current models of the universe could possibly be accounted for in the neutrinos - if it turns out the neutrinos actually have mass.
SuperK has provided good experimental evidence for the existence of neutrino mass. However, whether this accounts for the missing mass or not is still up to debate.
I was under the impression that it's still an open question whether neutrino oscillations occur.
The SuperK experiment did detect the neutrino oscillations so the fact that it happens is somewhat well established. The findings also provide strong evidence for the existence of neutrino mass since other explanations have been eliminated.
Yes, but the whole point in going undersea is the vast size of the site. The mines in the mountains are rather limited in size and access - and still they dont shield well enough and produce too many false hits/events. Undersea you can install an arbitrary number of detectors, and the shielding is perfect.
The problem with undersea detectors is that you can't control the water quality as well as in a tank. Also there is a limitation on the effective size of the tank due to the attenuation of the cherenkov radiation by water. Pure 18megaohm water has an attenuation length of about 300 meters(the intensity drops by ~67% after 300m) so the volume you're sampling is limited by the number and location of the detectors. True you can add more detectors but there are pratical problems with that.
The shielding in the mines are pretty good considering its about 1500m underground so you have about 1500m of earth and rock shielding you. However the ocean detectors can have more shielding if it's placed at a sufficient depth.
I don't know what became of DUMAND; it may have fallen prey to Congress in a budget cycle, because it was too small to have a constituency to defend it. Kind of like NASA's science programs.
I'm working in one of the labs that collobrated for DUMAND and I believe that it died due to budget cuts. Some of the detector strings are being used in NESTOR in Greece though.
There's a difference between what they print and what's legally binding. It's probably time for a lawyer to weigh in here, but from what little I know I strongly suspect that sentence can't be legally binding. If it's not legally binding, it may as well not be there. So I wouldn't be breaking any promises by offering object code to folks who might use it in ways that don't exactly please almighty Compaq.
So it may not be illegal to pass the object code on. That doesn't really change the morality of the situation. I believe Kant's categorical imperative (an action is moral only it can be an universal law) applies. Suppose you or someone else does that and these optimizations start popping up in egcs/gcc. Compaq is probably going to get pissed and may not be willing to help gcc/linux efforts in the future. Other companies may see this example and decide not to support the community in the future. Not a good thing.
Personally I don't see how this is different from Microsoft's actions. In both cases someone is using shady/unethical, if legal, means to steal ideas from a company. I would prefer giving up that extra 5% speed boost in order to keep the moral high ground. Wouldn't you?
That's some weird shit, man:) but what's so hard about typing a(b(x)) or: c(x){ return a(b(x)); }
What happens if the way the functions are combined can't be determined until runtime or if one of the functions can't be determined until runtime(a(x) = x+y where y is something that depends on the system state). In scheme (and probably lisp also) you would do something like: ((compose a (lambda (x) (+ x y))) x) and since lambda lets you create functions on the fly, the result of the compose can be determined at runtime.
My girlfriend told me a while back that ALL people are only something like 5 or 6 people away from each other. (I guess as in a who-knows-who kind of way) Anybody else knows more about this?
I believe this is false. Counterexample:
There are people in remote region that do not have contact with many people outside their groups. Say there exists a tribe (lets call them a) in a forest in Indonesia. Suppose the only contact that this group has with the outside world is through some anthropologists. Now suppose there was another tribe(b) in the same region that had contact only with a. Assume there are also tribes c and d that is in the same situation as a and b but in a totally different region, maybe Africa. Now consider the degrees of separation between a child in tribe d and a child in tribe b. Clearly it would be something like child(b)->parent->tribe a-> anthropologist ->?->anthropologist->tribe c->parent->child(d). In order for the six degrees of separation to be effective, the two anthropologists have to know each other directly. This isn't necessarily true given the number of anthropologists around.
I believe the six degrees of separation came about when someone figured that everyone knows at least 30 other people. Therefore a given person is separated by one person from 30*30=900 people. Analogously a person is separated by 6 people from 30^7~18 billion. However this doesn't take into account the redundancy in the relationships.
For example, many of the people that your friends know are from small cliches so the real relationships appear like many tightly interconnected clusters with a few connections between clusters.
BTW, I think I've been doing too many math proofs.
Slashdot Mirror
QNX is designed as a real time OS. It really isn't for consumer apps. It's pretty well regarded for RT work.
Although I'm in opposition to the majority here and will probably get negative moderation for this, I think that Katz is overreacting. There are several problems with Katz's article.
A major fault is that Katz doesn't provide any evidence to support his claims. He cites emails from several principles and administrators but doesn't give us a copy of the report, just a list of characteristics. We're not even sure if the list of characteristics is complete. The url for the halifax paper is link to a bank robber being caught not a "geek profile." In addition I'm curious why a canadian law enforcement agency has the profile and is giving it to canadian papers. Toss in the lack of coverage in other media sources and I'm sceptical as to the validity of the profile.
My other problem with this is that Katz seems to see a lot of the reaction to the Columbine incident as being "anti-Geek." He also seems to believe that profiles aren't necessary. Although, one would ideally want schools to evaluate everyone individually, schools have limited resource so it makes sense to have a profile that selects those most likely to be violent/dangerous/in need of help and focus the resources on those people. In analogy, think about how many system administrator read through system log files every day and how many use logcheck, swatch, etc. to just screen out the important ones based on a profile.
Katz claims that "bullies and predator" that pick on other children aren't singled out but several of the points in the checklist apply
Come from dysfunctional homes.
Experience unstable self-esteem.
Have experience with chronic bullying and drug use.
I think the second item is applicable and since most bullies usually have a dysfunctional family file the first one applies. In addition, bullying is often used to bolster a lack of self-esteem so the second item probably also fits. Katz's assertion about teachers is not valid since the profile is supposed to pick out potentially dangerous students. Whether schools/teachers are responsible for this is a valid question but is not importance in the context of a discussion on the merits of the profile.
Katx also goes on to bring in Mosaic-2000. Doing so is irresponsible and does not contribute anything to the article. Given that the details of how the program identifies "dangerous" students and how this program will be used, claiming that this program will select geeks is not very credible.
All in all, I think that Katz is overreacting or delibrately trying to provoke a reaction among the Slashdot community. His evidence is based on heresay, and links that don't check out. The lack of coverage in other media also discredits his article. The widespread coverage that the national media gave to Mosaic-2000 makes their silence on this profile all the more damning.
Granted the data seems to only imply a correlation but correlations are often useful. While they do not imply that one factor causes the other they do allow one make fairly accurate predictions. For example, the presence of smoke and a fire are strongly correlated so if you see smoke you can usually predict that there is a fire.
If you consider some philosophical stances (e.g. Hume), correlations are the only thing that we have since we can not prove causation for anything. We base science on very strongly correlated things. Nothing tells us the sun will rise in the east tomorrow but we are fairly confident that it will do so tomorrow since it has done so every morning. (For those that claim that physics tells us the sun will rise in the east, what insures that the laws of physics won't change tomorrow?)
Yeah there's a buffer overflow in the software. This is pretty wierd/bad since it's one the only pieces of software that has a security hole put in it on purpose and with a lot of forethought. check out this for more details.
The AOL IM actually has a buffer overflow exploit present. Basically whenever an AOL client connected to the server, the server smashed the stack and executed a piece of code that would send a packet back to the server. This let AOL change the authentication on the fly without updating the client. Of course, it also opened up some security holes. This was discussed on bugtraq in August.
The article indicates that the working theory behind this is that glucose is the thing that really matters. If that's the case then drinking gatorade or eating anything that's high in glucose will have an effect. So its not just potatoes.
The researchers have no clue why barley works so it could be that any food would work. Without more studies I wouldn't go out and eat ten pounds of potatoes the night before an exam.
But the lines still tied up even when there is no traffic. Plus modem users tend to use the line for a lot longer. Most conversations don't last an hour.
The ACLU post is somewhat slanted and gives the advisory a negative spin. If you read the advisory, the FEC says that the valuation needs to consider part of the cost of running computer and website towards the $250 limit.
In this case, the guy running the website needs to determine what part of his costs the advocacy website took up. Then if these costs exceed $250, he needs to register.
The Commission notes that there are minimal costs associated with creating the web site. Some portion of the previous expenses described in your request could be apportioned to each and every web site that you construct as part of your business. These overhead costs would include, for example, the fee to secure the registration of domain name, the amounts you invested in your hardware, and the utility costs to create the site.
Here the FEC seems to indicate that costs for just running the website needs to be considered. For example, if the DNS registration takes 35 a year, then cost needs to be divided by the number of separate DNS names he is using and then the cost for just the names he is using for the website needs to be considered. Also in valuating the cost of the website Leo just needs to consider the cost it took to prepare the site excluding his contribution in time(e.g. if he had to pay x dollars for the rights to use the images on the web site, he needs to include these x dollars in the valuation).
But that wasn't enough for the FEC. In an advisory opinion issued at Smith's request, the FEC said that it determines the value of web sites by counting, among other factors, the cost of the computer hardware and software used to create the site. If the computer cost more than $250, the FEC said, its owner would have to meet the filing and disclosure requirements of federal law.
The ACLU's characterization of the FEC ruling makes it harsher then it seems. If the computer cost over 1000, then the full cost of the computer only needs to be consider if all you do is run the political website on the computer. If all you do is create the website and set it up on a free homepage then you would need to file only if getting the images and processing them cost over $250. Also the FEC advisory seems to have been stricter since Leo was solicting donations for a candiate.
The ACLU seems to have made the ruling more ominous and threatening then it really is in order to drum up support and contributions. However IANAL so I may have interpeted the FEC advisory incorrectly.
It gets worse, the original poster was a chemical engineer. Of course he or she probably just had a mental slip up.
The energy incident on the Earth can be calculated by estimating the energy the sun emits (assume its a 5500K blackbody) and then figuring out how much is incident on a disc of the earth's diameter at ~ 1 AU away. If I remember right, the figure comes out to something like 14 W/m^2 within an order of magnitude. If we achieve the same efficiency plants do we'll be able to get about 30-40% of it in usable form (which is damn good).
What frequencies can the material respond to ? This question could be important to the space program, if materials can be made that convert even a fraction of the radiation from the sun to usable energy there could be a great saving in mission mass requirements ?
You can tailor its frequency response by attaching side groups to the porpyrhin rings or by changing the conjungation of some of the bonds within the rings. Most chlorophyll is most sensitive at about 720nm and 640nm since the sun's energy output peaks there.
Unfortunately this sort of material wouldn't be too effective in space without a lot of shielding. Most organics are fairly fragile and exposing it to the conditions in space would cause it to break down. Add in high energy photons(gamma, UV, x-ray) and the molecules start breaking down quickly.
(*)- Yes I'm aware you could create a system to generate a system that say generates ATP, and then uses the ATP to fuel a reductase or oxidase in order to run an electrolytic cell. This sort of system may work well for biological systems which have power consumptions on the order of 120 W (this is based on energy requirements of 2500 Kcal/day, fyi 1 Calorie in the nutrional sense equals 1000 calories in the biological sense). Photosynthetic systems work great in biology since plants concentrate energy over long periods of time, e.g. it takes 3-4 months to generate the energy required to produce a couple ears of corn.
The best efficiencies I've seen so far is about 17% so its not that great. OTOH the efficiencies of combustion engines and power plants are only on the order of about 20-40%. I believe that maximum efficiency possible with Carnot egnine is about 40% with the current temperatures our engines run at.
I think the author made a clear point about OSS resembling scientific communities rather than Communist/Marxist communities. His main point seemed to be that OSS resembled scientific communities and suffers from the same problems.
The sotry doesn't seem very believable. The most recent reports were of quantum computers able to factor the number 4. Although breakthroughs happen, I doubt that any breakthrough of this magnitude happened. It's sort of like someone suddenly building a pentium III when everyone else was building 8088 or m68ks. In addition the lack of details make the story pretty suspect.
That means that I can get the VHDL description of the device, and drop it into an FPGA or ASIC (field programmable gate array and application specific integratted circuit) and make a single-chip solution to some embedded problem. Who would buy the actual silicon from Zilog?
A FPGA from Xilinx costs about $20. The Z-80 costs a few dollars. Multiply the difference by about 1 million and you see significant savings by using the Z80 from Zilog.
How are they going to filter out the light produced by bioluminescent marine organisms? I thought they were common in the deep ocean.
I believe that the bioluminesence occurs at a wavelength quite different from the cherenkov radiation that the neutrino interactions produce. The neutrino interactions produce radiation at about ~400-500 nm which is right at or above the upper edge of human vision. So you can probably filter out bioluminescence by constructing the appropriate filter or ignoring lower energy photons.
That about wraps it up. I haven't had time to check out the details of this proposal. I'll be interested to see how they plan to get the water sufficiently clear that they can detect the scintillations from the muons. If the water is too murky, then the tiny Cherenkov flashes get absorbed, and you don't get any signal. Perhaps the sea water clears up if you go down deep enough?
It's surprising but some locations in the ocean have water clear enough that the attenuation length is about 200m. For example, the DUMAND site off Hawai'i had water that was about that clear. For comparision 18megaohm (100% pure) water has an attenuation length of about 300m so its not that bad.
In this example, gravity is a force of nature that is thought of in two ways: Strong nuclear force, and Weak nuclear force. These two forces combine to be what we call gravity.
The strong nuclear and weak nuclear force are different from gravitational forces. The strong nuclear force is mediated by gluons or mesons depending on whether it is affecting quarks or hadrons. The weak nuclear force is mediated by W-,W+, and Z0 bosons. The two forces do not combine to form gravity. Gravitons are postulated to mediate gravitational attractions but has not been detected yet.
It is a rare event to actually stop a nutrino, and the chances are slim that you can force it to happen in a lab. So some smart scientist decided one day to use an old abandoned mine under mount fuji in Japan. There is several giga-tons of mountain for nutrinos to go thru untill the poor particle finds itself in a big nutrino trap. hehehehe The equipment is so sensitive that nothing must ever move in its presence, and people are advised to not go near them.
That is totally untrue. I know for a fact that SuperK is located in Toyama near Mizumi. Also its in a aluminum mine. Last I heard Mt. Fuji wasn't being mined. Also the equipment is not that sensitive. People routinely go to the top of the tank to adjust stuff. In addition, the mining company is doing some blasting a couple hundred meters away the control center and tank and this is not affecting the instruments.
I thought it was interesting because scientists theorize that the "missing" mass associated with current models of the universe could possibly be accounted for in the neutrinos - if it turns out the neutrinos actually have mass.
SuperK has provided good experimental evidence for the existence of neutrino mass. However, whether this accounts for the missing mass or not is still up to debate.
I was under the impression that it's still an open question whether neutrino oscillations occur.
The SuperK experiment did detect the neutrino oscillations so the fact that it happens is somewhat well established. The findings also provide strong evidence for the existence of neutrino mass since other explanations have been eliminated.
The problem with undersea detectors is that you can't control the water quality as well as in a tank. Also there is a limitation on the effective size of the tank due to the attenuation of the cherenkov radiation by water. Pure 18megaohm water has an attenuation length of about 300 meters(the intensity drops by ~67% after 300m) so the volume you're sampling is limited by the number and location of the detectors. True you can add more detectors but there are pratical problems with that.
The shielding in the mines are pretty good considering its about 1500m underground so you have about 1500m of earth and rock shielding you. However the ocean detectors can have more shielding if it's placed at a sufficient depth.
I don't know what became of DUMAND; it may have fallen prey to Congress in a budget cycle, because it was too small to have a constituency to defend it. Kind of like NASA's science programs.
I'm working in one of the labs that collobrated for DUMAND and I believe that it died due to budget cuts. Some of the detector strings are being used in NESTOR in Greece though.
So it may not be illegal to pass the object code on. That doesn't really change the morality of the situation. I believe Kant's categorical imperative (an action is moral only it can be an universal law) applies. Suppose you or someone else does that and these optimizations start popping up in egcs/gcc. Compaq is probably going to get pissed and may not be willing to help gcc/linux efforts in the future. Other companies may see this example and decide not to support the community in the future. Not a good thing.
Personally I don't see how this is different from Microsoft's actions. In both cases someone is using shady/unethical, if legal, means to steal ideas from a company. I would prefer giving up that extra 5% speed boost in order to keep the moral high ground. Wouldn't you?
That's some weird shit, man :) but what's so hard about typing a(b(x)) or: c(x){ return a(b(x)); }
What happens if the way the functions are combined can't be determined until runtime or if one of the functions can't be determined until runtime(a(x) = x+y where y is something that depends on the system state). In scheme (and probably lisp also) you would do something like:
((compose a (lambda (x) (+ x y))) x)
and since lambda lets you create functions on the fly, the result of the compose can be determined at runtime.
I believe this is false. Counterexample:
There are people in remote region that do not have contact with many people outside their groups. Say there exists a tribe (lets call them a) in a forest in Indonesia. Suppose the only contact that this group has with the outside world is through some anthropologists. Now suppose there was another tribe(b) in the same region that had contact only with a. Assume there are also tribes c and d that is in the same situation as a and b but in a totally different region, maybe Africa. Now consider the degrees of separation between a child in tribe d and a child in tribe b. Clearly it would be something like child(b)->parent->tribe a-> anthropologist ->?->anthropologist->tribe c->parent->child(d). In order for the six degrees of separation to be effective, the two anthropologists have to know each other directly. This isn't necessarily true given the number of anthropologists around.
I believe the six degrees of separation came about when someone figured that everyone knows at least 30 other people. Therefore a given person is separated by one person from 30*30=900 people. Analogously a person is separated by 6 people from 30^7~18 billion. However this doesn't take into account the redundancy in the relationships.
For example, many of the people that your friends know are from small cliches so the real relationships appear like many tightly interconnected clusters with a few connections between clusters.
BTW, I think I've been doing too many math proofs.