Is someone with the technical abilities to build a guided missile really going to be deterred by the fact that off the shelf civilian GPS firmware is crippled in this way? The specifications for the GPS system are publicly available and many manufacturers have successfully used them to build GPS receivers, so it can't be rocket science (pun intended). And even if one were to use off the shelf GPS components, how hard would it be to modify the firmware? Firmware is just software stored in some type of read only or flash memory. Would it be that hard to download, inspect and modify it? It seems to me it would be about as hard as removing copy protection from a game.
Yes, it is a substantial deterrent. The limitations are imposed in the lowest-level parts of the GPS receiver, the first stage of data processing at which it is technically feasible to infer speed and altitude. The hardware that runs this code is highly specialized - it's a mixed analog/digital RF ASIC that is designed in hardware to run that specific code, including the limitation. There is little distinction between hardware and firmware at that point, and it is likely that the code responsible for the limitation is not programmable/reprogrammable at all. The sophistication needed to build a rudimentary short-range guided missile is surprisingly basic, and many hobbyists (or terroristically-inclined groups) could do it without too much difficulty, on a five-figure or low-six-figure budget. The GPS limitation significantly hinders the on-target accuracy that could be achieved, since the high speed terminal phase of the flight is where excellent guidance in an absolute reference frame is most important. The sophistication needed to build or microscopically alter a GPS receiver without the limitation is significantly greater (and in an entirely different technical field) than what is needed to build a missile that would benefit from that GPS guidance.
The limitations at issue are not accuracy limits. Nowadays there are no real differences in accuracy between military and civilian GPS, since selective availability was turned off years ago. The problem is that civilian GPS firmware prohibits the device from giving a fix if it is above a certain altitude (around 60,000 feet) and moving faster that about mach 1. This makes it useless for midcourse guidance of a rocket, which is the point.
Apparently I already have a plasma rifle in my garage! It shoots plasma and cuts metal with it - and just like this laser rifle, it requires compressed air and a remote power supply connected by an umbilical. I also have a MOLTEN METAL WELDING RIFLE! Similarly, it requires a power supply and umbilical assembly. Strangely, none of my actual rifles need cables or power supplies attached to them in order to operate.
In many places, truth is not a defense. If it harms someone, it did harm. You can't badmouth certain industries in TX or FL, for example, regardless of the truth of the statements. Too bad free speech doesn't exist in the US anymore. We should move to some place more free, like Soviet Russia.
That is plainly incorrect. As a constitutional matter, truthful negative statements are protected speech in the United States. You have misinterpreted the precedent.
Anybody thought to wonder why the car was searched by the valet service instead of the the TSA itself?
The very reason is because the contents of your car has long been held protected under the 4th Amendment to the US Constitution
A search by a private individual at the behest of the government is the same as a search by the government. Anyone acting on behalf of the government (whether directly employed by them or not) is bound by the constitutional limitations on government action. Source: IIAL, and I don't have time to look up the cite.
Are all the servers in the Microsoft data centre purely physical or are most of the servers actually virtualized and therefore not consuming much electrical power on an individual basis?
A server is a server. You can run as many VM's as you want on a server, but every VM exists on a real, physical, rack-mounted, power-consuming server.
You never know what's in that baggage. Some of the most valuable cargo is transported as carry-on, personally supervised baggage. Some things are worth saving, either due to extreme economic value or personal or cultural significance.
A large portion of that list doesn't look anti-science. Business deregulation? Firing regulatory officials for "lack of leadership"? Discontinuing a mandatory census? Rolling back environmental regulations? Withdraw from Kyoto Accord? Changes to fisheries regulations? Procedural changes for public hearings on pipeline work? And so on... These are not "anti-science" changes. They are anti-liberal, anti-environmentalist, and pro-business political moves. Think there might be some political bias by the author of this list?
Back in the olden days, equipment like this had serial port configuration interfaces which were intended for use by nearby administrators, via terminals and small local networks with no connectivity beyond the local facility. If longer distance administration was required, it was over dedicated copper loops. The internet was simply not used for these kinds of systems, and the idea that those devices would ever end up on a globally-accessible network with millions of untrusted devices was incomprehensible. As technology developed and the internet took over as the primary means of long-distance networked communication, these legacy devices were incorporated into a network environment that their engineers had never even considered. It's just not what they were made for. The devices are not to blame. Engineers and administrators who put them on public networks certainly are.
If in the United States, the answer is universally "NO". Decryption cannot be mandated. There have been a couple close calls over the years under some unusual circumstances, but the general principle stands.
The only actual solution is to stream the video to off-site hosted storage, preferably in an inconvenient foreign jurisdiction. If it's stored on the device, it's subject to seizure - whether encrypted or not. Losing the video is often worse than having it viewed by someone against your will. And rest assured, if you record something really bad, there's a good chance someone will destroy the recording device (whether the perpetrator is government or non-government).
Mod parent up! This is the most accurate and succinct explanation of the way American culture and law differs from most of the world. It all boils down to limitation of government and emphasis on individual rights and responsibilities. With that said, there are legal remedies for completely egregious abuse of the civil legal system. Suing based on fabricated facts (not mistakes of fact, but actual lies) or with absolutely no legal basis for the claim gives rise to a counterclaim for abuse of process or malicious prosecution, and will get an attorney disciplined or disbarred. The system is supposed to be self-policing, and it generally works. Cases like this one are usually far less clear-cut than they seem, and are rarely totally meritless. As an attorney, most of the ridiculous and abusive lawsuits that I have seen were filed by people representing themselves without an attorney.
Like many non-rigorous descriptions, the summary makes the mistake of describing the uncertainty principle as if it is a measurement problem, where the lack of precision somehow arises from inadequate measurement technology. This is not a correct statement of the uncertainty principle. The fundamental issue is that the conjugate variable values are linked on a quantum level, such that there is a certain amount of natural, inherent uncertainty in their collective values due to the statistical/wavelike nature of the quantum particle. With perfect measurement, there is still uncertainty in the pair of values for any conjugate variables because the uncertainty lies in the actual values themselves. Position and momentum are the quintessential conjugate pair. The Heisenberg uncertainty principle is sometimes framed as the idea that you cannot know the speed and position of a particle at the same time. But it's more correct to say that a particle does not HAVE an exact speed and position at the same time. This weak measurement technique is certainly useful and interesting since it allows some observations of wavefunctions without collapse, but it does not actually allow the measurement of conjugate variables more precisely than the uncertainty principle allows - because the values themselves do not exist more precisely than that.
*This description is based one one of the multiple interpretations of quantum mechanics, and probably does not accurately represent physical reality, only our human understanding of a part of reality that we have not really figured out completely yet.
I do not know much about defamation law in other countries, but in the US there would be no valid case. The statements are derogatory, but are opinions and not facts. Only provably false statements of fact can give rise to an action for defamation in the United States. Of course anyone can always try to sue for anything, but the plaintiff here would lose quickly and probably face a judgment for costs and fees for filing a case unsupported by law (Rule 11).
As you have clearly discovered, a properly operating business needs a balanced team of managers and employees who can handle ALL aspects of the company's functions, not just engineering the product. Making the product is arguably no more or less important than selling it and collecting the money. You're the tech guy and visionary founder, and that's great. But you need a marketing and sales genius to handle the other functions. That person (and his or her subordinates) are critical to your success, so you want someone who is as invested as you are. That means a top-level executive with equity-based compensation. You need to pick someone with experience operating in a small startup environment (or if not, at least a business degree with a good understanding of small business operations), who has the personal assets to weather unprofitability, and who is comfortable staking his entire return (or close to it) on the success of the company. Guaranteed payments and large salaries for founding executives are inadvisable. Compensation should be tied 100% to profitability, or at least to rational business milestones if you don't anticipate profitability for awhile and you have the capital to support it.
You are wrong. Steel and stainless steel parts can also be 3D printed.
Not directly. You can 3D print patterns which are used to make molds for casting the parts in steel. I certainly don't know of any home 3D printers which actually print in steel.
No, he meant what he said. Laser sintering makes high strength metal parts directly. The resulting product is very strong and a variety of materials are available. This is already being used to make implantable joint replacements. I have had a few one-off parts made this way, and the results are impressive.
http://www.youtube.com/watch?v=88BPmL8cGAo
Couldn't Schmidt's trip be construed as a violation of the Logan Act?
I don't see how. He didn't engage in any sort of negotiation with the DPRK administration. Of course everyone he was in contact with while in-country was effectively a representative of the regime, but he didn't represent himself as an agent of the United States and attempt to engage in diplomatic negotiation. He just visited, smiled, and nodded.
Um, no. It converts matter to other matter and release the potential energy stored within it. There is a theory about some 0.001% of the matter disappearing, but it's nowhere near "converted well".
Mass and energy are the *same thing* for these purposes. Whatever energy is released in the burning of a fire is manifested as a decrease in the mass of the reaction products. It's a tiny decrease, but real. The conversion is perfectly efficient, too. So although burning stuff may not be able to convert very much mass to energy, it does so "well" by most definitions.
It's a very small number of collisions compared to the number of protons. One source says something like 20 collisions per crossing, which works out to about 600 million collisions per second. That may seem like a large number, but it's extremely small compared to the number of protons passing close to one another every second!
Each beam is really a loop of proton bunches, since they circulate indefinitely around the ring. There are 2808 bunches per beam maximum, and each bunch contains about 1.15x10^11 protons. The bunch length is something like 8cm, and the diameter actually varies a lot but runs about a fraction of a millimeter through most of the ring, and focuses down to about 16 microns (hair diameter) at the crossing point where the beams collide. The design minimum bunch spacing is 25ns (about 25 feet at the speed of light), but they have been running wider spacing than that I think. The bunches are not uniformly spaced, either, since there are large gaps to allow time for the beam dump and injection apparatus to activate without getting proton blasted during switching.
Well all they are doing to accelerating a few atoms. you should not need very much power to accelerate masses that small.
You might think so based on the miniscule resting mass of the particles, but remember that they are being accelerated very close to the speed of light, so they gather a staggering amount of kinetic energy (and/or additional mass, relativistically). The LHC particle beam is the closest thing to the death star's destruction ray that humans have created. Each of the collider's two counter-rotating sets of particle bunches carries 360,000,000 joules of energy - about as much as 300 sticks of dynamite, or a passenger train moving 90MPH. The stored energy in the pair of beams could melt a ton of copper instantly. All that, in a "flying rod of protons" about 0.3mm in diameter and moving 186,000 miles per second. The LHC uses a pair of huge graphite cylinders 22 feet long and 2 feet in diameter to dispose of the accelerated protons. Each beam dump is water cooled and surrounded by 750 tons of radiation shielding deep underground. But even that isn't quite good enough on its own. The particles beam is deflected into a circular pattern as it is directed into the graphite absorber so the energy is spread over a larger volume to avoid excessively damaging the graphite.
Slashdot Mirror
Is someone with the technical abilities to build a guided missile really going to be deterred by the fact that off the shelf civilian GPS firmware is crippled in this way? The specifications for the GPS system are publicly available and many manufacturers have successfully used them to build GPS receivers, so it can't be rocket science (pun intended). And even if one were to use off the shelf GPS components, how hard would it be to modify the firmware? Firmware is just software stored in some type of read only or flash memory. Would it be that hard to download, inspect and modify it? It seems to me it would be about as hard as removing copy protection from a game.
Yes, it is a substantial deterrent. The limitations are imposed in the lowest-level parts of the GPS receiver, the first stage of data processing at which it is technically feasible to infer speed and altitude. The hardware that runs this code is highly specialized - it's a mixed analog/digital RF ASIC that is designed in hardware to run that specific code, including the limitation. There is little distinction between hardware and firmware at that point, and it is likely that the code responsible for the limitation is not programmable/reprogrammable at all. The sophistication needed to build a rudimentary short-range guided missile is surprisingly basic, and many hobbyists (or terroristically-inclined groups) could do it without too much difficulty, on a five-figure or low-six-figure budget. The GPS limitation significantly hinders the on-target accuracy that could be achieved, since the high speed terminal phase of the flight is where excellent guidance in an absolute reference frame is most important. The sophistication needed to build or microscopically alter a GPS receiver without the limitation is significantly greater (and in an entirely different technical field) than what is needed to build a missile that would benefit from that GPS guidance.
The limitations at issue are not accuracy limits. Nowadays there are no real differences in accuracy between military and civilian GPS, since selective availability was turned off years ago. The problem is that civilian GPS firmware prohibits the device from giving a fix if it is above a certain altitude (around 60,000 feet) and moving faster that about mach 1. This makes it useless for midcourse guidance of a rocket, which is the point.
Apparently I already have a plasma rifle in my garage! It shoots plasma and cuts metal with it - and just like this laser rifle, it requires compressed air and a remote power supply connected by an umbilical. I also have a MOLTEN METAL WELDING RIFLE! Similarly, it requires a power supply and umbilical assembly. Strangely, none of my actual rifles need cables or power supplies attached to them in order to operate.
In many places, truth is not a defense. If it harms someone, it did harm. You can't badmouth certain industries in TX or FL, for example, regardless of the truth of the statements. Too bad free speech doesn't exist in the US anymore. We should move to some place more free, like Soviet Russia.
That is plainly incorrect. As a constitutional matter, truthful negative statements are protected speech in the United States. You have misinterpreted the precedent.
Anybody thought to wonder why the car was searched by the valet service instead of the the TSA itself?
The very reason is because the contents of your car has long been held protected under the 4th Amendment to the US Constitution
A search by a private individual at the behest of the government is the same as a search by the government. Anyone acting on behalf of the government (whether directly employed by them or not) is bound by the constitutional limitations on government action. Source: IIAL, and I don't have time to look up the cite.
Are all the servers in the Microsoft data centre purely physical or are most of the servers actually virtualized and therefore not consuming much electrical power on an individual basis?
A server is a server. You can run as many VM's as you want on a server, but every VM exists on a real, physical, rack-mounted, power-consuming server.
You never know what's in that baggage. Some of the most valuable cargo is transported as carry-on, personally supervised baggage. Some things are worth saving, either due to extreme economic value or personal or cultural significance.
A large portion of that list doesn't look anti-science. Business deregulation? Firing regulatory officials for "lack of leadership"? Discontinuing a mandatory census? Rolling back environmental regulations? Withdraw from Kyoto Accord? Changes to fisheries regulations? Procedural changes for public hearings on pipeline work? And so on... These are not "anti-science" changes. They are anti-liberal, anti-environmentalist, and pro-business political moves. Think there might be some political bias by the author of this list?
Back in the olden days, equipment like this had serial port configuration interfaces which were intended for use by nearby administrators, via terminals and small local networks with no connectivity beyond the local facility. If longer distance administration was required, it was over dedicated copper loops. The internet was simply not used for these kinds of systems, and the idea that those devices would ever end up on a globally-accessible network with millions of untrusted devices was incomprehensible. As technology developed and the internet took over as the primary means of long-distance networked communication, these legacy devices were incorporated into a network environment that their engineers had never even considered. It's just not what they were made for. The devices are not to blame. Engineers and administrators who put them on public networks certainly are.
Just delete this and start over. Really. How does this word-salad get approved for publication to millions of people?
I'm annoyed that I can't "facet" my Facebook account into family, friends and work, and hide things from each of these.
You can. That's what "lists" are for. You add people to lists, and set default privacy settings for the lists.
If in the United States, the answer is universally "NO". Decryption cannot be mandated. There have been a couple close calls over the years under some unusual circumstances, but the general principle stands.
The only actual solution is to stream the video to off-site hosted storage, preferably in an inconvenient foreign jurisdiction. If it's stored on the device, it's subject to seizure - whether encrypted or not. Losing the video is often worse than having it viewed by someone against your will. And rest assured, if you record something really bad, there's a good chance someone will destroy the recording device (whether the perpetrator is government or non-government).
Mod parent up! This is the most accurate and succinct explanation of the way American culture and law differs from most of the world. It all boils down to limitation of government and emphasis on individual rights and responsibilities. With that said, there are legal remedies for completely egregious abuse of the civil legal system. Suing based on fabricated facts (not mistakes of fact, but actual lies) or with absolutely no legal basis for the claim gives rise to a counterclaim for abuse of process or malicious prosecution, and will get an attorney disciplined or disbarred. The system is supposed to be self-policing, and it generally works. Cases like this one are usually far less clear-cut than they seem, and are rarely totally meritless. As an attorney, most of the ridiculous and abusive lawsuits that I have seen were filed by people representing themselves without an attorney.
Like many non-rigorous descriptions, the summary makes the mistake of describing the uncertainty principle as if it is a measurement problem, where the lack of precision somehow arises from inadequate measurement technology. This is not a correct statement of the uncertainty principle. The fundamental issue is that the conjugate variable values are linked on a quantum level, such that there is a certain amount of natural, inherent uncertainty in their collective values due to the statistical/wavelike nature of the quantum particle. With perfect measurement, there is still uncertainty in the pair of values for any conjugate variables because the uncertainty lies in the actual values themselves. Position and momentum are the quintessential conjugate pair. The Heisenberg uncertainty principle is sometimes framed as the idea that you cannot know the speed and position of a particle at the same time. But it's more correct to say that a particle does not HAVE an exact speed and position at the same time. This weak measurement technique is certainly useful and interesting since it allows some observations of wavefunctions without collapse, but it does not actually allow the measurement of conjugate variables more precisely than the uncertainty principle allows - because the values themselves do not exist more precisely than that.
*This description is based one one of the multiple interpretations of quantum mechanics, and probably does not accurately represent physical reality, only our human understanding of a part of reality that we have not really figured out completely yet.
I do not know much about defamation law in other countries, but in the US there would be no valid case. The statements are derogatory, but are opinions and not facts. Only provably false statements of fact can give rise to an action for defamation in the United States. Of course anyone can always try to sue for anything, but the plaintiff here would lose quickly and probably face a judgment for costs and fees for filing a case unsupported by law (Rule 11).
As you have clearly discovered, a properly operating business needs a balanced team of managers and employees who can handle ALL aspects of the company's functions, not just engineering the product. Making the product is arguably no more or less important than selling it and collecting the money. You're the tech guy and visionary founder, and that's great. But you need a marketing and sales genius to handle the other functions. That person (and his or her subordinates) are critical to your success, so you want someone who is as invested as you are. That means a top-level executive with equity-based compensation. You need to pick someone with experience operating in a small startup environment (or if not, at least a business degree with a good understanding of small business operations), who has the personal assets to weather unprofitability, and who is comfortable staking his entire return (or close to it) on the success of the company. Guaranteed payments and large salaries for founding executives are inadvisable. Compensation should be tied 100% to profitability, or at least to rational business milestones if you don't anticipate profitability for awhile and you have the capital to support it.
You are wrong. Steel and stainless steel parts can also be 3D printed.
Not directly. You can 3D print patterns which are used to make molds for casting the parts in steel. I certainly don't know of any home 3D printers which actually print in steel.
No, he meant what he said. Laser sintering makes high strength metal parts directly. The resulting product is very strong and a variety of materials are available. This is already being used to make implantable joint replacements. I have had a few one-off parts made this way, and the results are impressive. http://www.youtube.com/watch?v=88BPmL8cGAo
I can't even get my Swann DVR to work right WITH the login credentials!
Post to undo accidental mod. Others with points: mod this up!
Couldn't Schmidt's trip be construed as a violation of the Logan Act?
I don't see how. He didn't engage in any sort of negotiation with the DPRK administration. Of course everyone he was in contact with while in-country was effectively a representative of the regime, but he didn't represent himself as an agent of the United States and attempt to engage in diplomatic negotiation. He just visited, smiled, and nodded.
Um, no. It converts matter to other matter and release the potential energy stored within it. There is a theory about some 0.001% of the matter disappearing, but it's nowhere near "converted well".
Mass and energy are the *same thing* for these purposes. Whatever energy is released in the burning of a fire is manifested as a decrease in the mass of the reaction products. It's a tiny decrease, but real. The conversion is perfectly efficient, too. So although burning stuff may not be able to convert very much mass to energy, it does so "well" by most definitions.
It's a very small number of collisions compared to the number of protons. One source says something like 20 collisions per crossing, which works out to about 600 million collisions per second. That may seem like a large number, but it's extremely small compared to the number of protons passing close to one another every second!
Each beam is really a loop of proton bunches, since they circulate indefinitely around the ring. There are 2808 bunches per beam maximum, and each bunch contains about 1.15x10^11 protons. The bunch length is something like 8cm, and the diameter actually varies a lot but runs about a fraction of a millimeter through most of the ring, and focuses down to about 16 microns (hair diameter) at the crossing point where the beams collide. The design minimum bunch spacing is 25ns (about 25 feet at the speed of light), but they have been running wider spacing than that I think. The bunches are not uniformly spaced, either, since there are large gaps to allow time for the beam dump and injection apparatus to activate without getting proton blasted during switching.
Well all they are doing to accelerating a few atoms. you should not need very much power to accelerate masses that small.
You might think so based on the miniscule resting mass of the particles, but remember that they are being accelerated very close to the speed of light, so they gather a staggering amount of kinetic energy (and/or additional mass, relativistically). The LHC particle beam is the closest thing to the death star's destruction ray that humans have created. Each of the collider's two counter-rotating sets of particle bunches carries 360,000,000 joules of energy - about as much as 300 sticks of dynamite, or a passenger train moving 90MPH. The stored energy in the pair of beams could melt a ton of copper instantly. All that, in a "flying rod of protons" about 0.3mm in diameter and moving 186,000 miles per second. The LHC uses a pair of huge graphite cylinders 22 feet long and 2 feet in diameter to dispose of the accelerated protons. Each beam dump is water cooled and surrounded by 750 tons of radiation shielding deep underground. But even that isn't quite good enough on its own. The particles beam is deflected into a circular pattern as it is directed into the graphite absorber so the energy is spread over a larger volume to avoid excessively damaging the graphite.