its totally different since a missle generates a really small reflection while an active
transmission is easier to track in on
It's not a problem in principle. Whether the target has a beacon or is reflecting a continuous-wave guidance radar makes no difference to the receiver - if power is a problem, the ground station transmitting the radar can increase its power output without bound.
And as for HARM (and their Shrike prececessors), they are popular against surface targets because it's far more difficult to distinguish targets on the ground (or at sea), where there's plenty of clutter to confuse the signal. Not so in space, where there's nothing but the interceptor and target for thousands of miles.
if i have a warhead that will obliterate anything within, say, a 100-ft. radius, then
all i have to do is get within 100 feet of my target.
Most SAMs and AAMs use fragmentation-type warheads, so as you get further away, damage is less likely -- there's no blast radius of guaranteed destruction as you imply. Besides, you would have to use a hell of a lot of explosive for a 100 ft radius -- probably 100 lbs or more. Most AAMs carry 5-10 lbs, SAMs carry a little more but not much.
Furthermore, the NMD kill vehicle is designed for "kinetic kill", that is, interception via impact. This is the lesson from the Gulf War, when Patriot SAMs were ineffective against incoming scuds in spite of scoring several "hits" - they simply managed to randomly redirect a randomly fired missile. With "kinetic kill", the collision energy completely vaporizes the warhead and (hopefully) neutralizes any enclosed chemical and biological agents -- due to the huge closing velocity, no explosives are needed.
I grant you that a GPS transmitter on the target warhead would help you to get close to it. But that isn't the hard part. The hard part is hitting the missile. If GPS has an accuracy measured in anything more than inches, it would be useless for terminal guidance. Furthermore, even ground-based radar will tell you where the warhead is, with arbitrary accuracy, following which you can uplink this data to the interceptor. The hardest part of the task is guiding the interceptor to intersect with the missile at a closing velocity of of around 20,000 mph, even when it knows exactly where it is, and this was in fact accomplished. I still think this was a success.
And as for "liberals" being the ones opposed to NMD, let's not forget that it was a Democratic president who revived the notion.
Firstly, I have to say that I am not often impressed by the writings of JonKatz. I find them whiny and hysterical, but most importantly, poorly researched. They don't live up to the standards of what one would expect from a staff writer of an important publication such as Slashdot. His articles rarely do anything more than preach to the choir, rehashing the beliefs of a majority of slashdotters, rather than exploring the issues in detail and challenging widely-held assumptions -- which would make for MUCH more interesting reading (and discussion).
On the other hand, the JonKatz bashing has gotten out of hand. A typical rebuttal to a JonKatz piece can be summed up as "You Suck". These sorts of people should be introduced to the part of the User Preferences page where you can exclude stories by specific authors. Either that or they should be a little more creative and thoughtful and less infantile in their posting.
Many of the infected servers aren't really being used at all. They are still
showing their default Microsoft homepages and are simply running as a service under Windows NT. In
those cases, the people on whose computers IIS is running probably don't even know they have a web
server.
It seems to me that this is a potentially larger problem with most distros of Linux. Quite often a default installation package will include Apache, which is happily installed and activated without the user being actively informed how to care for it. I know for a fact that this was true for RedHat 6.2, though more recent distributions of RedHat have fixed this. Since Apache is free (as in beer), while IIS is not, more Linux users generally have Apache than Windows users have IIS.
How vulnerable is Apache to an attack of this sort? And, furthermore, could there be a more prudent way to distribute Apache? (Such as with a disclaimer? Or only by specific request?)
So you're saying that you would trade the
de facto regulation of a business trade group for the de jure regulation of the federal government? Forgive me if I remain suspicious.
In this case, if you download MP3s, you really would be downloading Communism.
A good bitwise (or symbolwise) measure of distance between two sequences is the Hamming distance, which is the number of different symbols between the two sequences. A simple checksum will basically tell you whether the Hamming distance is zero (same checksum) or nonzero (different checksum).
I'm sure it's possible to generalize the concept.
I'm not aware of any specific work, but a simple solution would be something like a blockwise checksum. If enough blocks match up, it could raise a flag indicating the presence of possible spam. Ideally the blocks would be large enough that the concatenated checksum is short, but short enough that differences are easily captured.
You could try a keyword search for "error detection" or "checksums" using a publication search engine like Citeseer, or INSPEC if you have access through work or school.
US citizen trying to get the hang of all these darn parties while I wait for Immigration to let me
the heck in.
Here's all you need to know:
Liberals (or "Grits") - The centrist ruling party. Progressive Conservatives (or "Tories) - Traditional right-of-centre alternative to the Liberals, until a decade ago when its support splintered. New Democratic Party - Traditional "third party", left-of-centre, have never formed a government. Canadian Alliance - Formed in 1987 as the "Reform party", a Western party that split from the Tories. Currently involved in a fratricidal leadership controversy; likely to disintegrate before the next election. Bloc Quebecois - A Quebec-based party that split largely from the Tories. They run candidates only in Quebec and campaign solely on Quebec independence.
The Canadian government is influenced by business, as is any government. However, this is complicated by a few things. Firstly, the government has been dominated by one party for nearly a decade, while the opposition parties have basically crumbled -- so there is virtually no effective opposition at the federal level. Secondly, information technology issues get little attention from the public -- there are a number of more pressing issues currently facing the government such as aboriginal rights, the poor state of health care, and regional discontent. It's hard to get anyone to pay attention to anything else. Thirdly, US policy has influence over Canadian policy -- since the US is our biggest trading partner, it is difficult for us to pursue economic policies that come into direct conflict with theirs.
Finally, and possibly most importantly, us Canadians don't have a culture of defending rights and freedoms. Many British loyalists settled in Canada after fleeing the American revolution.
We were granted independence from Britain peacefully in 1867, under the motto of "peace, order, and good government" (note the lack of mention of liberty). We have gun control and socialized medicine. We had neither a constitution nor bill of rights until 1980 -- they were controversial at the time and many Canadians still think them unnecessary. Sure, we get uptight about freedom of speech and so on, but there's no tradition of "live free or die" -- we like consensus, getting along, and doing what is in the public interest over what is best for the individual. I suspect that new regulations on copyright enforcement will recieve a relatively easy ride in Canada.
Bah, I say. The information from this
research hasnt provided the answers we seek about sub-atomic structure.
For one thing, it isn't new matter being created here, just the forced fusion of heavy elements. For another thing, this isn't just an exercise in who can make the heaviest element. While most of the artificial heavy elements discovered so far have half-lives of microseconds, current theory predicts that there is a band of super-heavy elements that are relatively stable, with half-lives of seconds or more. The only way to test the theory is to actually create such elements.
If I were going to make a claim of this magnitude I
would make sure that there is repeatability of the results before I opened my mouth about it.
Firstly, this discovery isn't anything that will result in fundamental shifts in scientific knowledge, nor is it anything that will affect the daily lives of individuals (in the same way as, say, nuclear fission). So I'm not sure why you would consider this a discovery of great magnitude, aside from the fact that an average person could probably understand the nature of the discovery. Furthermore, repeatability is the work of other researchers, so in this case the system worked as intended.
I believe that this research is much needed and I detest the fact that this type of bogus science really
hurts the rest of the legitimate scientific community by making funds that much harder to come by.
Again, I disagree. The research in question was neither "bogus", nor did it hurt the reputation of the rest of the scientific community. There was some evidence from an experiment that could have been a legitimate discovery, and it was published as such, then withdrawn when the evidence was reviewed.
In fact, as many posters have pointed out, the forthrightness of the scientists in pointing out their own mistakes can only help their reputations. The research funding agencies understand how science works, and won't likely turn off the money taps because of one failed experiment.
I may disagree with Craig Mundie, but I must congratulate him for his tenacity and bravery. He's taken quite a bit of time to explain the MS position on Open Source, and to engage in dialogue with the Open Source community. It's particularly admirable in light of the lack of respect that the OS community as a whole has given him, in spite of their public gestures.
If the OS people aren't careful, they may make Mundie look like the hero, while coming across themselves as flaming ideologues.
try to compress the "random" string of numbers; if you can compress a string of
random numbers, it isn't
Not really. Since pi is some constant, and not generated by a random process, the most meaningful description of its compressibility is its Kolmogorov complexity, which refers to the shortest program capable of re-generating the original string.
Unfortunately, Kolmogorov complexity is not computable in general.
I live in Canada and have only seen one application for solar cells here - they're used by one of the
cities to power lights that let drivers know about school zones.
A few years ago in Edmonton the EPCOR building installed solar cells on its roof; the power replaces the conventional power supply to the top few floors of the building.
The issue is not water per se -- although as one poster pointed out, existence of water could make a manned mission much cheaper. The issue is that liquid water and an energy source are the only two things that life on Earth seems to require. Thus, wherever liquid water is, there would likely be life. The implications of discovering life on another planet would be profound, and well worth the expense.
Thanks a lot. I don't mean to beat this to death, but I'd be surprised if the IEEE ever changed its policy. Strictly speaking, the journals are published by a sponsoring technical society (not directly by the IEEE), and the technical societies are organized and run mostly by the academics who do the publishing. It seems to work quite well.
I think the biggest hurdle facing a manned mission to mars is how to coop-up 5-10 people for 2
years in a tin can with the living space of an apartment without them going bonkers and killing each
other.
Aren't they doing something like that on Fox this season?
what does everyone
think the reality of a manned mission in our lifetime is?
It depends on a couple of things:
Cost. This is probably the big one. Estimates for the cost of a manned Mars mission range from $20 billion to over $100 billion; bearing in mind that estimates for the cost of the Apollo project drastically undershot the actual cost, the mission would probably cost $200 billion or more with existing technology. Meanwhile, NASA is working on single-stage-to-orbit (SSTO) technology, as well as "living off the land" technology - producing propellant from Martian gases, etc., which if successful will cut the cost of launch by an order of magnitude. With a price tag of hundreds of billions, there probably won't be a mission for 30 years or more. However, if the cost goes down to around $10 billion, a mission could happen within a decade. If a dramatic increase in technology reduced it to around $1 billion, I can imagine private investors funding the mission -- imagine Larry Ellison or Bill Gates as the first man on Mars!
Reason to Go. Right now the reasons to go include "because it's there" and "because we might find evidence of life". The Apollo missions happened as quickly as they did due to political competition; that's unlikely to be repeated. However, if compelling evidence of Martian life is ever found, along with the region of Mars in which it is most likely to be located, I expect that will dramatically increase interest in a manned mission.
scientists aren't asking for their work to be copyright-free
Of course not! As a scientist I am very happy to let anyone peruse my results for free (in fact I encourage it), but I want to maintain control over how my results are presented. This is because I want to retain control over changes to my work -- I don't want someone taking my work, making trivial changes, removing my name as an author, and claiming credit. The system of citation is the accepted means by which scientific work is modified and advanced, which gives credit to the truly original and fundamental works in the field while preserving them unchanged. It's difficult to maintain such a system if copyright is completely abandoned.
Slashdot Mirror
its totally different since a missle generates a really small reflection while an active transmission is easier to track in on
It's not a problem in principle. Whether the target has a beacon or is reflecting a continuous-wave guidance radar makes no difference to the receiver - if power is a problem, the ground station transmitting the radar can increase its power output without bound.
And as for HARM (and their Shrike prececessors), they are popular against surface targets because it's far more difficult to distinguish targets on the ground (or at sea), where there's plenty of clutter to confuse the signal. Not so in space, where there's nothing but the interceptor and target for thousands of miles.
if i have a warhead that will obliterate anything within, say, a 100-ft. radius, then all i have to do is get within 100 feet of my target.
Most SAMs and AAMs use fragmentation-type warheads, so as you get further away, damage is less likely -- there's no blast radius of guaranteed destruction as you imply. Besides, you would have to use a hell of a lot of explosive for a 100 ft radius -- probably 100 lbs or more. Most AAMs carry 5-10 lbs, SAMs carry a little more but not much.
Furthermore, the NMD kill vehicle is designed for "kinetic kill", that is, interception via impact. This is the lesson from the Gulf War, when Patriot SAMs were ineffective against incoming scuds in spite of scoring several "hits" - they simply managed to randomly redirect a randomly fired missile. With "kinetic kill", the collision energy completely vaporizes the warhead and (hopefully) neutralizes any enclosed chemical and biological agents -- due to the huge closing velocity, no explosives are needed.
You don't need to decode the GPS transmission. Just home in on it.
Again, only trivially different from homing in on a radar reflection.
I grant you that a GPS transmitter on the target warhead would help you to get close to it. But that isn't the hard part. The hard part is hitting the missile. If GPS has an accuracy measured in anything more than inches, it would be useless for terminal guidance. Furthermore, even ground-based radar will tell you where the warhead is, with arbitrary accuracy, following which you can uplink this data to the interceptor. The hardest part of the task is guiding the interceptor to intersect with the missile at a closing velocity of of around 20,000 mph, even when it knows exactly where it is, and this was in fact accomplished. I still think this was a success.
And as for "liberals" being the ones opposed to NMD, let's not forget that it was a Democratic president who revived the notion.
What happens if you umount /me?
Is that what happens after fsck /me?
Or is that what happens when you sleep 8h?
Firstly, I have to say that I am not often impressed by the writings of JonKatz. I find them whiny and hysterical, but most importantly, poorly researched. They don't live up to the standards of what one would expect from a staff writer of an important publication such as Slashdot. His articles rarely do anything more than preach to the choir, rehashing the beliefs of a majority of slashdotters, rather than exploring the issues in detail and challenging widely-held assumptions -- which would make for MUCH more interesting reading (and discussion).
On the other hand, the JonKatz bashing has gotten out of hand. A typical rebuttal to a JonKatz piece can be summed up as "You Suck". These sorts of people should be introduced to the part of the User Preferences page where you can exclude stories by specific authors. Either that or they should be a little more creative and thoughtful and less infantile in their posting.
Many of the infected servers aren't really being used at all. They are still showing their default Microsoft homepages and are simply running as a service under Windows NT. In those cases, the people on whose computers IIS is running probably don't even know they have a web server.
It seems to me that this is a potentially larger problem with most distros of Linux. Quite often a default installation package will include Apache, which is happily installed and activated without the user being actively informed how to care for it. I know for a fact that this was true for RedHat 6.2, though more recent distributions of RedHat have fixed this. Since Apache is free (as in beer), while IIS is not, more Linux users generally have Apache than Windows users have IIS.
How vulnerable is Apache to an attack of this sort? And, furthermore, could there be a more prudent way to distribute Apache? (Such as with a disclaimer? Or only by specific request?)
What about Billy Beer?
We elected the wrong Carter.
So you're saying that you would trade the de facto regulation of a business trade group for the de jure regulation of the federal government? Forgive me if I remain suspicious.
In this case, if you download MP3s, you really would be downloading Communism.
Yes, but then invalid HTML would be an even easier giveaway for rejecting spam.
A good bitwise (or symbolwise) measure of distance between two sequences is the Hamming distance, which is the number of different symbols between the two sequences. A simple checksum will basically tell you whether the Hamming distance is zero (same checksum) or nonzero (different checksum).
I'm sure it's possible to generalize the concept. I'm not aware of any specific work, but a simple solution would be something like a blockwise checksum. If enough blocks match up, it could raise a flag indicating the presence of possible spam. Ideally the blocks would be large enough that the concatenated checksum is short, but short enough that differences are easily captured.
You could try a keyword search for "error detection" or "checksums" using a publication search engine like Citeseer, or INSPEC if you have access through work or school.
US citizen trying to get the hang of all these darn parties while I wait for Immigration to let me the heck in.
Here's all you need to know:
Liberals (or "Grits") - The centrist ruling party.
Progressive Conservatives (or "Tories) - Traditional right-of-centre alternative to the Liberals, until a decade ago when its support splintered.
New Democratic Party - Traditional "third party", left-of-centre, have never formed a government.
Canadian Alliance - Formed in 1987 as the "Reform party", a Western party that split from the Tories. Currently involved in a fratricidal leadership controversy; likely to disintegrate before the next election.
Bloc Quebecois - A Quebec-based party that split largely from the Tories. They run candidates only in Quebec and campaign solely on Quebec independence.
Of course we also have the usual fringe parties - the Marijuana party, the Communist party, the Green party, and so on. My favourite is the Natural Law party, whose basic policy is to teach Canadians to levitate using Yoga.
John Nunziatta will whine
Probably, but he's no longer in parliament. I wonder if he's still bitter?
The Canadian government is influenced by business, as is any government. However, this is complicated by a few things. Firstly, the government has been dominated by one party for nearly a decade, while the opposition parties have basically crumbled -- so there is virtually no effective opposition at the federal level. Secondly, information technology issues get little attention from the public -- there are a number of more pressing issues currently facing the government such as aboriginal rights, the poor state of health care, and regional discontent. It's hard to get anyone to pay attention to anything else. Thirdly, US policy has influence over Canadian policy -- since the US is our biggest trading partner, it is difficult for us to pursue economic policies that come into direct conflict with theirs.
Finally, and possibly most importantly, us Canadians don't have a culture of defending rights and freedoms. Many British loyalists settled in Canada after fleeing the American revolution. We were granted independence from Britain peacefully in 1867, under the motto of "peace, order, and good government" (note the lack of mention of liberty). We have gun control and socialized medicine. We had neither a constitution nor bill of rights until 1980 -- they were controversial at the time and many Canadians still think them unnecessary. Sure, we get uptight about freedom of speech and so on, but there's no tradition of "live free or die" -- we like consensus, getting along, and doing what is in the public interest over what is best for the individual. I suspect that new regulations on copyright enforcement will recieve a relatively easy ride in Canada.
Bah, I say. The information from this research hasnt provided the answers we seek about sub-atomic structure.
For one thing, it isn't new matter being created here, just the forced fusion of heavy elements. For another thing, this isn't just an exercise in who can make the heaviest element. While most of the artificial heavy elements discovered so far have half-lives of microseconds, current theory predicts that there is a band of super-heavy elements that are relatively stable, with half-lives of seconds or more. The only way to test the theory is to actually create such elements.
So, bah yourself.
If I were going to make a claim of this magnitude I would make sure that there is repeatability of the results before I opened my mouth about it.
Firstly, this discovery isn't anything that will result in fundamental shifts in scientific knowledge, nor is it anything that will affect the daily lives of individuals (in the same way as, say, nuclear fission). So I'm not sure why you would consider this a discovery of great magnitude, aside from the fact that an average person could probably understand the nature of the discovery. Furthermore, repeatability is the work of other researchers, so in this case the system worked as intended.
I believe that this research is much needed and I detest the fact that this type of bogus science really hurts the rest of the legitimate scientific community by making funds that much harder to come by.
Again, I disagree. The research in question was neither "bogus", nor did it hurt the reputation of the rest of the scientific community. There was some evidence from an experiment that could have been a legitimate discovery, and it was published as such, then withdrawn when the evidence was reviewed. In fact, as many posters have pointed out, the forthrightness of the scientists in pointing out their own mistakes can only help their reputations. The research funding agencies understand how science works, and won't likely turn off the money taps because of one failed experiment.
I may disagree with Craig Mundie, but I must congratulate him for his tenacity and bravery. He's taken quite a bit of time to explain the MS position on Open Source, and to engage in dialogue with the Open Source community. It's particularly admirable in light of the lack of respect that the OS community as a whole has given him, in spite of their public gestures.
If the OS people aren't careful, they may make Mundie look like the hero, while coming across themselves as flaming ideologues.
try to compress the "random" string of numbers; if you can compress a string of random numbers, it isn't
Not really. Since pi is some constant, and not generated by a random process, the most meaningful description of its compressibility is its Kolmogorov complexity, which refers to the shortest program capable of re-generating the original string. Unfortunately, Kolmogorov complexity is not computable in general.
I live in Canada and have only seen one application for solar cells here - they're used by one of the cities to power lights that let drivers know about school zones.
A few years ago in Edmonton the EPCOR building installed solar cells on its roof; the power replaces the conventional power supply to the top few floors of the building.
The issue is not water per se -- although as one poster pointed out, existence of water could make a manned mission much cheaper. The issue is that liquid water and an energy source are the only two things that life on Earth seems to require. Thus, wherever liquid water is, there would likely be life. The implications of discovering life on another planet would be profound, and well worth the expense.
Thanks a lot. I don't mean to beat this to death, but I'd be surprised if the IEEE ever changed its policy. Strictly speaking, the journals are published by a sponsoring technical society (not directly by the IEEE), and the technical societies are organized and run mostly by the academics who do the publishing. It seems to work quite well.
I think the biggest hurdle facing a manned mission to mars is how to coop-up 5-10 people for 2 years in a tin can with the living space of an apartment without them going bonkers and killing each other.
Aren't they doing something like that on Fox this season?
Can you point me to some references on this?
what does everyone think the reality of a manned mission in our lifetime is?
It depends on a couple of things:
scientists aren't asking for their work to be copyright-free
Of course not! As a scientist I am very happy to let anyone peruse my results for free (in fact I encourage it), but I want to maintain control over how my results are presented. This is because I want to retain control over changes to my work -- I don't want someone taking my work, making trivial changes, removing my name as an author, and claiming credit. The system of citation is the accepted means by which scientific work is modified and advanced, which gives credit to the truly original and fundamental works in the field while preserving them unchanged. It's difficult to maintain such a system if copyright is completely abandoned.