There's a big difference between preparing for the possibility (you don't seriously believe there will never again be war in North America, do you?),...
"Never" is a very long time.
Will there be a war next week? Probably not (99.999%).
Next month?
Next year?
In the next 10 years?
20 years?
50 years?
Have you died of old age or heart disease or such by that time?
100 years?
200 years?
500 years?
Who knows? Destabilization happens fast, and the prelude is usually only obvious in hindsight. The prepper philosophy is to admit that nobody can answer your question and to take some degree of precaution as a hedge against the risk.
Don't look at sun with remaining good eye. And sunlight isn't coherent light, so the comparison is skewed from the start. I recommend that you try looking into an eye-safe laser beam from a few hundred yards away (so the energy of the beam is spread over a spot two to three feet in diameter). The experience will not be dangerous, but nevertheless quite unpleasant, and this little experiment should cure the misconception that looking into a laser from afar couldn't be a problem.
Obviously the lack of temporal coherence in sunlight is irrelevant here. Spatial coherence does have some influence on how bright the source appears. Sunlight is fairly spatially coherent at about 4.7mrad divergence on Earth. That's comparable to a bad laser pointer, and not too much worse than a good one. Coherence is much less important to this issue than M^2 value or other measures of beam "quality" that correlate to focal spot size. The sun wins on those metrics. I've stared into many laser beams of different powers and wavelengths, sometimes intentionally, occasionally accidentally. I've been on the receiving end of high power beams from long distances just to see what it's like. A 150mW 532nm beam of about 1.5mrad (a decent quality DPSS module) is pretty darn bright from 3/4 mile away at night, but it's definitely not dangerous. Try it.
To the point, militant Islam really, really wants to be in charge, which makes pretty much everyone in the world either an immediate target or a future target. It's odd that you don't seem to recognize that.
Militant Islam isn't a single entity, it's an ideology followed by many competing groups. The attacks happened because someone, or some group thought it would further there goals. They thought it would be a better use of resources than attacking the US, or Hungary, or keeping fighters in Syria (and they might be correct, or they might not be correct, but they thought it would be a good idea).
So the real question is, who are these people making decisions, and why did they make those decisions? It's odd that you don't seem to recognize that.
That's like asking why the Nazis chose to invade Poland when they did, looking for some deep meaning or hidden complexity. They wanted to control it - along with everywhere else in the world. It was an easy target, so they hit it. When the goal is total subjugation of all targets, the rationale for which targets are selected first is sort of irrelevant.
How many "preppers" are there in the U.S. that believe the West is going to collapse into ruin any day now. All it will take is just the right spark to start the race/culture/religious/civil war.
There's a big difference between preparing for the possibility (you don't seriously believe there will never again be war in North America, do you?), versus believing you can bring it about yourself. Preppers recognize the reality that stable, peaceful societies never last forever and often devolve quickly without enough advance notice to avoid the fray. Terrorists believe they can cause that devolution.
IIIa, not IIIb. The CDRH requires that handheld pointing lasers meet the IIIa classification, which means less than 5mW output power among other things. Red laser pointers virtually all comply with this. Green pointers are hit-or-miss, since the cheap DPSS laser inside has highly variable power output depending on unpredictable factors. In my experience measuring the power output of green pointers (and I've measured a lot of 'em), they are generally 3-5mW but sometimes you get a hot one that pushes 5-10mW. They can all be cranked up with tinkering though, sometimes to 100mW or more! It's the tweaked green pointers and black-market IIIb and IV devices that cause some concern. 5mW in the eyeball is extremely unpleasant, but does not cause retinal damage - especially with the poor beam quality (and thus large focal spot size) of handheld lasers. A tweaked-out DPSS pointer running tens of milliwatts can definitely cause instant permanent damage at short range though, and the 500mW to 1.5W blue diodes are quite dangerous (but totally awesome).
Here's the thing, though: None of these lasers are really dangerous at long range. The beam quality is universally terrible, which results in high divergence and therefore large beam diameter at long range. The total amount of light produced by even the most powerful handheld lasers is not very much, and quickly loses its brilliance when spread over a circle a few meters in diameter. At one mile, a 2mrad beam will be approximately 10 feet in diameter. A 1W laser would then have an intensity of 0.138W/m^2, or 0.0138mW/cm^2. That's nothing. The sun is over 100 times brighter than that.
I'm curious how someone on the ground is able to aim at the windshield of the cockpit from the ground.
What am I missing here?
You're not missing anything. It's very hard most of the time to hit the windshield of an aircraft from any nearby point on the ground. The hardest part, though, is keeping the laser pointed at the target. It's essentially impossible. People have tested this repeatedly - it's on YouTube. The bottom line is that a handheld laser can only ever manage to very briefly flash the cockpit of a flying aircraft, and the beam intensity at such a range is non-dangerous even if the laser is quite powerful. It may be surprising to a pilot and could cause a brief but dangerous distraction, but the hype of blindness (even temporary vision loss) is grossly exaggerated. Basic math and empirical testing shows that pretty conclusively.
There are a lot of people in US prisons, you know, and if there is such a thing as an unpriveleged inmate/attorney conversation (I have no idea how it works), then there are probably a lot of those going on.
There isn't.
What if they call the attorney's office and they're not there? Is that priveleged?
Yes.
All communications between an attorney and client are privileged, with a tiny set of exceptions which are, in general, not applicable here. Calls to an attorney's office are privileged even if the attorney never got on the phone. Communication with the support staff can be just as damaging as communications with the attorney if revealed to the other side. The mere fact of an attorney's consultation or representation is confidential. Much of the time, the fact of representation will be publicly known - but occasionally it can be critically important that a client's consultation with counsel be kept secret. Having the government intercept and record ANY communication with counsel is extremely problematic. Jails and prisons have systems in place which are intended to ensure that phone calls to legal counsel are not recorded (the inmate or attorney notifies the staff that the call is privileged, and a different phone system or procedure is used). The revelation here is that those safeguards are apparently all for show, and they record and archive the calls anyways.
Posting to undo accidental down-moderation. You have a great point, which I was trying to reward with an "insightful" mod. As a litigation attorney, I deal with nothing but high-stakes contentious situations. Most often, the people (both lawyers and litigants) who complain the most about their adversaries are actually the most unnecessarily aggressive and unpleasant participants. It seems to be a form of psychological projection. "You're totally unreasonable! You're acting in bad faith and obstructing the case! No we won't give you any documents, and we won't settle! We want sanctions, and we won't participate in mediation!"
Ironically, Snowden's own revelations indicated that the data would be more secure in the US than in Europe, since we collect foreign data with wild abandon, and still apply some limits to domestic surveillance.
It failed because the cost of tickets was unsustainable...
The Concorde failed because a tire exploded, it streaked terrifyingly across the Paris sky trailing hundreds of feet of fire, and crashed in a giant fireball, killing everyone. And then the fleet was instantly and irrevocably grounded. The program had its economic issues over the years, but was still in operation nonetheless - until the disaster.
OOh so in your world, you can only be a real maker or a true scotsman if you work with metal or wood.
And why is that exactly? Is there another reason other than wanting to feel superior?
But in most cases you don't need a 3D printer that oozes soft plastic crap.
Most 3D printers will happily print ABS, which is one of the most commonly used plastics.
You can only be a "true maker" if you have the capability of working with a variety of materials to suit the needs of the part, just like you can only be a "true maker" if you have some ability to work with electronics, plumbing/hydraulics, and mechanics, and if you can make parts using a variety of different fabrication methods depending on what suits the conditions. Choosing appropriate materials is a critical part of making something. "Soft plastic crap" presumably refers to PVA, which is mechanically unsuitable for most applications. ABS is more usable, but still not a reasonable engineering material for a lot of uses. Wood isn't either. It's pretty fair to say that someone is not a "true maker" unless they can select between materials and fabrication methods that are reasonable for a variety of different engineering needs, and that necessarily includes subtractive manufacturing of metals - the #1 most common method of making strong mechanical parts.
I have a £550 Ebay 50W laser which can cut 6mm acrylic well (though with bevelled edges currently - I'm hoping to be able to do something about this though with some better set up). I've done 6mm ply but it all came out rather burnt. Again, I'm hoping to do better once I find the ideal settings. Overall I've been impressed with what it can do for the price.
A compressed air jet can greatly improve performance on thick material. If your edge quality issues are a result of melting in the heat-affected zone, that would be a major improvement. If it's a beam diameter problem, then a longer focal length lens will help. It's also good to make sure your focal point is inside the workpiece, not on the surface, if you are seeing a wider kerf on the bottom than the top.
Yeah I wish he went more into details on this.. he mentions a 60w laser at one point. Watts, wavelength, thickness, inches per second would have been nice.
All commercial CO2 lasers for cutting use are the same wavelength, 10,600nm. Conveniently, that wavelength is completely blocked by almost everything except air - including glass, plastics, and water. This makes it comparatively safe to work with, as high power invisible lasers go. Standard shop safety goggles provide complete eye protection, and a direct beam to the eye is necessary to cause injury since the light cannot penetrate the cornea to focus on the retina like most laser beams. But I digress... The power needed to cut a material depends on the thickness, edge quality required, and speed required. Like welding, there are no clear rules, only general guidelines based on experience. 60W is not much power for laser cutting, and would be unlikely to make a clean edge on 1/4" plastic at any reasonable speed, or to give an acceptable cut on 3/8" material at all unless assisted by a compressed gas jet, which cheap and low-powered laser cutters do not use.
I happen to need some weird Delrin parts for a 1960s oscilloscope. My parts have cracks and Delrin is almost impossible to glue unless the surface is chemically prepared.
I wonder if Joshua can tell us if there's a way to prepare the surface correctly at home? And what specific adhesive works?
Nothing sticks WELL to Delrin/acetal. Epoxies can be used to bond it, but it's not recommended at all if any other means of connection is feasible. Its non-reactive and low-friction properties are directly related to its very low surface energy, which makes bonding work poorly. Acrylic is much better if you need to glue, since superglue (cyanoacrylate) bonds extremely well and matches its mechanical properties fairly well. Polycarbonate is also good.
I have an off-grid cabin on a mountaintop in the middle of nowhere. It's not a survival campsite, but it's quite remote. I can work from there if I need to, and I sometimes do. I have rainwater collection, solar power with plenty of storage, and line of sight to a cell tower on another peak several miles away. Full 4G data from all providers - but only once you're up on the peak, not on the way in. This is a reliable and comfortable way to work from a wilderness location. But this kind of system does not work for survival camping, especially moving between locations. Reliability requires a fixed location with line of sight data service, and a fixed solar installation. If your priority is primitive camping, I don't think this can be achieved effectively. But if your priority is to experience isolated wilderness while definitely staying connected, a small cabin (even a primitively constructed shelter) at a carefully chosen location can work just fine.
What happened to the legal standard that new laws cannot be applied ex post facto?
I don't understand how that relates to this situation. A prohibited ex post facto law is one which criminalizes or imposes a penalty for an act which occurred before the law was enacted. For example, a new law which raises your taxes for last year and makes you pay the difference now. Or a law which makes it a crime to have previously consumed alcohol before the law was passed. This does not seem related to the case at hand.
The preliminary injunction entered by the district court is hereby vacated and the case remanded for such further proceedings as may be appropriate.
It doesn't overturn the previous finding that the program is unconstitutional - it makes it like that finding never existed in the first place.
That's not what that means. The appellate court vacated the preliminary injunction, they did not reverse a legal determination on constitutionality. As one of the other commenters noted, I actually oversimplified the ruling - they didn't even determine that the plaintiff definitely can't pursue the case, they just determined that he can't get a preliminary injunction because there aren't enough facts to support his standing yet.
"The appellate court explicitly did NOT "overturn" the district court's substantive finding that the program is unconstitutional. This ruling is procedural, and unrelated to the merits of the legal arguments about constitutionality of the NSA program."
+1 for that part of your comment.
"The court instead found that this particular plaintiff does not have standing to challenge the program in court."
-1 for that part of your comment. They didn't rule that he didn't have standing (well, 1 of the 3 judges did, but the majority did not), or that the trial can't proceed. They simply said that there's not enough evidence of standing shown in the pre-trial phase for an preliminary injunction (which they say requires a higher bar than the standing requirement needed to proceed with the trial). The trial can proceed, where more evidence can be obtained and presented.
BTW - the latest empytwheel.net post highlights some brand new evidence showing that the plaintiff has standing.
You're right. I oversimplified it. They found that, based on the record as it stands currently, there is not adequate evidence to show standing - but there might be later after more discovery. The case is not dismissed, the preliminary injunction is just denied.
The appellate court explicitly did NOT "overturn" the district court's substantive finding that the program is unconstitutional. This ruling is procedural, and unrelated to the merits of the legal arguments about constitutionality of the NSA program. The court instead found that this particular plaintiff does not have standing to challenge the program in court. It's a very problematic ruling, raises a lot of issues, and in my opinion should be reversed - but it certainly does not overturn the lower court's finding that the program is unconstitutional as a matter of law.
"web-scale data centers are designed to cope with hardware failures". So.... it's OK if you use my motherboard design and they randomly fail, because you should just make up for that in software or hardware redundancy? Um, no.
That's exactly what it means, and how it works. When you have tens of thousands of nodes, some of them WILL eventually fail during operation, no matter how good the hardware is. Thus, the software must be designed to accommodate hardware failures and seamlessly continue operation without interruption or data loss. If you already have to design the software to handle that anyway, then there is not much incentive to go to great lengths to improve hardware reliability. Whether the failure rate is 1:100000 or 1:1000 annually, the result is the same on the software side. But if the less reliable hardware is dramatically cheaper (which it is), then it makes more sense to use the cheap hardware and replace it more often.
If you're logged in and have good karma, you should be able to disable ads as a "courtesy" to dedicated contributors. Or just use an adblock extension.
This lawsuit is a legal mess, destined to fail. In fact, it already did fail and they're just trying futilely to revive it. All applicable statutes of limitations passed years ago. You can't wait decades to file a lawsuit. Equally as importantly, "The Marshall Islands" as a political subdivision does not have standing to sue for injuries that occurred to specific people and property there. Those people and property owners would have to sue, not their regional government. Finally, the decisions which were made and the actions taken were political decisions made by the United States in exercise of its sovereign authority - and you can't sue for that. It seems that the plaintiffs know this, which is why they are now trying to frame the lawsuit as a claim to enforce the NPT. The problem with that is, yet again, a lack of standing on several levels, and an inaccurate interpretation of the treaty itself. First, there is no cause of action through which any individual or entity can force the government to comply with or enforce a treaty. International relations are solely the sovereign domain of the federal government, and they can decide to abide by (or disregard) treaties as our elected officials see fit. Second, the treaty is not being violated. It does not require disarmament, nor is there a mandatory timeline for any particular disarmament-related activity. It says the signatories will negotiate towards an agreement regarding disarmament. That's not an enforceable mandate in any meaningful sense. Why? Because the signatories never actually had any intention of disarming, so they made an agreement that didn't require them to disarm. A third party can't come in and force them to abide by a deal they didn't make in the first place.
Look, the Marshallese got screwed. There was a discriminatory component to that. It wouldn't happen the same way today. But the bottom line is that we needed a place to test weapons of mass destruction, and the Marshall Islands were the best choice available. So the US did what they had to do to make the program work. They should have provided market-based compensation for the taking of land, and they should have relocated everyone out of the zone of danger, turning the entire area into a restricted military installation before blowing it up repeatedly. There should have been no injuries and no uncompensated loss of property. But the reasonable conclusion to take away from those events is not that nuclear weapons should be eliminated, or that the tests shouldn't have been conducted at that location. They served a critical purpose for national security, and anyone who says otherwise is a revisionist with an agenda.
Ever since their first widespread implementations in the mid 20th century, turbopumps have been powered by rocket propellants - either the same stuff they are pumping (F1 engine in the Saturn V), or a separate propellant dedicated to powering the pumps (Space Shuttle Main Engines). There are excellent reasons for this, and not many good reasons to use batteries and motors instead. Rocket propellant pumps require truly massive amounts of power to move thousands of gallons per minute of propellants at thousands of PSI pressure. The SSME turbopumps require over 70,000 horsepower per engine. Like all other rocket hardware, size and weight are extreme concerns. Power-to-weight ratio is the single most critical design goal. Rocket engines themselves burn the propellants they do specifically because those chemical combinations are the absolute best we have for producing the maximum amount of thermo-mechanical energy from the least mass, no-compromise. Using the same types of propellants to drive the turbopumps also provides the maximum achievable power to weight ratio. The SSME turbopumps produce over 100HP per pound, which is insanely high. No known electric motor technology can even reach that order of magnitude in power density, even considering only the actual motor itself! There is no legitimate contest in performance between a gas-driven turbopump and any other technology besides nuclear, and that's that. To make such a large compromise in power to weight ratio by using electric pumps is very odd. Yes, gas-driven turbopumps are really hard. They are the hardest part of building a large liquid rocket engine. But those challenges were first solved over 60 years ago, and avoiding a tough engineering exercise is no excuse for making a giant compromise in performance. The extra mass of that electric drive system could be replaced with propellant or cargo.
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"Never" is a very long time.
Will there be a war next week? Probably not (99.999%). Next month? Next year? In the next 10 years? 20 years? 50 years? Have you died of old age or heart disease or such by that time?
100 years? 200 years? 500 years?
Who knows? Destabilization happens fast, and the prelude is usually only obvious in hindsight. The prepper philosophy is to admit that nobody can answer your question and to take some degree of precaution as a hedge against the risk.
Don't look at sun with remaining good eye. And sunlight isn't coherent light, so the comparison is skewed from the start. I recommend that you try looking into an eye-safe laser beam from a few hundred yards away (so the energy of the beam is spread over a spot two to three feet in diameter). The experience will not be dangerous, but nevertheless quite unpleasant, and this little experiment should cure the misconception that looking into a laser from afar couldn't be a problem.
Obviously the lack of temporal coherence in sunlight is irrelevant here. Spatial coherence does have some influence on how bright the source appears. Sunlight is fairly spatially coherent at about 4.7mrad divergence on Earth. That's comparable to a bad laser pointer, and not too much worse than a good one. Coherence is much less important to this issue than M^2 value or other measures of beam "quality" that correlate to focal spot size. The sun wins on those metrics. I've stared into many laser beams of different powers and wavelengths, sometimes intentionally, occasionally accidentally. I've been on the receiving end of high power beams from long distances just to see what it's like. A 150mW 532nm beam of about 1.5mrad (a decent quality DPSS module) is pretty darn bright from 3/4 mile away at night, but it's definitely not dangerous. Try it.
To the point, militant Islam really, really wants to be in charge, which makes pretty much everyone in the world either an immediate target or a future target. It's odd that you don't seem to recognize that.
Militant Islam isn't a single entity, it's an ideology followed by many competing groups. The attacks happened because someone, or some group thought it would further there goals. They thought it would be a better use of resources than attacking the US, or Hungary, or keeping fighters in Syria (and they might be correct, or they might not be correct, but they thought it would be a good idea). So the real question is, who are these people making decisions, and why did they make those decisions? It's odd that you don't seem to recognize that.
That's like asking why the Nazis chose to invade Poland when they did, looking for some deep meaning or hidden complexity. They wanted to control it - along with everywhere else in the world. It was an easy target, so they hit it. When the goal is total subjugation of all targets, the rationale for which targets are selected first is sort of irrelevant.
How many "preppers" are there in the U.S. that believe the West is going to collapse into ruin any day now. All it will take is just the right spark to start the race/culture/religious/civil war.
There's a big difference between preparing for the possibility (you don't seriously believe there will never again be war in North America, do you?), versus believing you can bring it about yourself. Preppers recognize the reality that stable, peaceful societies never last forever and often devolve quickly without enough advance notice to avoid the fray. Terrorists believe they can cause that devolution.
Most laser pointers are class IIIb laser devices.
IIIa, not IIIb. The CDRH requires that handheld pointing lasers meet the IIIa classification, which means less than 5mW output power among other things. Red laser pointers virtually all comply with this. Green pointers are hit-or-miss, since the cheap DPSS laser inside has highly variable power output depending on unpredictable factors. In my experience measuring the power output of green pointers (and I've measured a lot of 'em), they are generally 3-5mW but sometimes you get a hot one that pushes 5-10mW. They can all be cranked up with tinkering though, sometimes to 100mW or more! It's the tweaked green pointers and black-market IIIb and IV devices that cause some concern. 5mW in the eyeball is extremely unpleasant, but does not cause retinal damage - especially with the poor beam quality (and thus large focal spot size) of handheld lasers. A tweaked-out DPSS pointer running tens of milliwatts can definitely cause instant permanent damage at short range though, and the 500mW to 1.5W blue diodes are quite dangerous (but totally awesome).
Here's the thing, though: None of these lasers are really dangerous at long range. The beam quality is universally terrible, which results in high divergence and therefore large beam diameter at long range. The total amount of light produced by even the most powerful handheld lasers is not very much, and quickly loses its brilliance when spread over a circle a few meters in diameter. At one mile, a 2mrad beam will be approximately 10 feet in diameter. A 1W laser would then have an intensity of 0.138W/m^2, or 0.0138mW/cm^2. That's nothing. The sun is over 100 times brighter than that.
I'm curious how someone on the ground is able to aim at the windshield of the cockpit from the ground.
What am I missing here?
You're not missing anything. It's very hard most of the time to hit the windshield of an aircraft from any nearby point on the ground. The hardest part, though, is keeping the laser pointed at the target. It's essentially impossible. People have tested this repeatedly - it's on YouTube. The bottom line is that a handheld laser can only ever manage to very briefly flash the cockpit of a flying aircraft, and the beam intensity at such a range is non-dangerous even if the laser is quite powerful. It may be surprising to a pilot and could cause a brief but dangerous distraction, but the hype of blindness (even temporary vision loss) is grossly exaggerated. Basic math and empirical testing shows that pretty conclusively.
"Strong indication... likely..."
So, are they priveleged or not?
They are.
There are a lot of people in US prisons, you know, and if there is such a thing as an unpriveleged inmate/attorney conversation (I have no idea how it works), then there are probably a lot of those going on.
There isn't.
What if they call the attorney's office and they're not there? Is that priveleged?
Yes.
All communications between an attorney and client are privileged, with a tiny set of exceptions which are, in general, not applicable here. Calls to an attorney's office are privileged even if the attorney never got on the phone. Communication with the support staff can be just as damaging as communications with the attorney if revealed to the other side. The mere fact of an attorney's consultation or representation is confidential. Much of the time, the fact of representation will be publicly known - but occasionally it can be critically important that a client's consultation with counsel be kept secret. Having the government intercept and record ANY communication with counsel is extremely problematic. Jails and prisons have systems in place which are intended to ensure that phone calls to legal counsel are not recorded (the inmate or attorney notifies the staff that the call is privileged, and a different phone system or procedure is used). The revelation here is that those safeguards are apparently all for show, and they record and archive the calls anyways.
Is there any reason at all for this to be on Slashdot, except to push a general political agenda?
Posting to undo accidental down-moderation. You have a great point, which I was trying to reward with an "insightful" mod. As a litigation attorney, I deal with nothing but high-stakes contentious situations. Most often, the people (both lawyers and litigants) who complain the most about their adversaries are actually the most unnecessarily aggressive and unpleasant participants. It seems to be a form of psychological projection. "You're totally unreasonable! You're acting in bad faith and obstructing the case! No we won't give you any documents, and we won't settle! We want sanctions, and we won't participate in mediation!"
Ironically, Snowden's own revelations indicated that the data would be more secure in the US than in Europe, since we collect foreign data with wild abandon, and still apply some limits to domestic surveillance.
It failed because the cost of tickets was unsustainable...
The Concorde failed because a tire exploded, it streaked terrifyingly across the Paris sky trailing hundreds of feet of fire, and crashed in a giant fireball, killing everyone. And then the fleet was instantly and irrevocably grounded. The program had its economic issues over the years, but was still in operation nonetheless - until the disaster.
OOh so in your world, you can only be a real maker or a true scotsman if you work with metal or wood.
And why is that exactly? Is there another reason other than wanting to feel superior?
But in most cases you don't need a 3D printer that oozes soft plastic crap.
Most 3D printers will happily print ABS, which is one of the most commonly used plastics.
You can only be a "true maker" if you have the capability of working with a variety of materials to suit the needs of the part, just like you can only be a "true maker" if you have some ability to work with electronics, plumbing/hydraulics, and mechanics, and if you can make parts using a variety of different fabrication methods depending on what suits the conditions. Choosing appropriate materials is a critical part of making something. "Soft plastic crap" presumably refers to PVA, which is mechanically unsuitable for most applications. ABS is more usable, but still not a reasonable engineering material for a lot of uses. Wood isn't either. It's pretty fair to say that someone is not a "true maker" unless they can select between materials and fabrication methods that are reasonable for a variety of different engineering needs, and that necessarily includes subtractive manufacturing of metals - the #1 most common method of making strong mechanical parts.
I have a £550 Ebay 50W laser which can cut 6mm acrylic well (though with bevelled edges currently - I'm hoping to be able to do something about this though with some better set up). I've done 6mm ply but it all came out rather burnt. Again, I'm hoping to do better once I find the ideal settings. Overall I've been impressed with what it can do for the price.
A compressed air jet can greatly improve performance on thick material. If your edge quality issues are a result of melting in the heat-affected zone, that would be a major improvement. If it's a beam diameter problem, then a longer focal length lens will help. It's also good to make sure your focal point is inside the workpiece, not on the surface, if you are seeing a wider kerf on the bottom than the top.
Yeah I wish he went more into details on this.. he mentions a 60w laser at one point. Watts, wavelength, thickness, inches per second would have been nice.
All commercial CO2 lasers for cutting use are the same wavelength, 10,600nm. Conveniently, that wavelength is completely blocked by almost everything except air - including glass, plastics, and water. This makes it comparatively safe to work with, as high power invisible lasers go. Standard shop safety goggles provide complete eye protection, and a direct beam to the eye is necessary to cause injury since the light cannot penetrate the cornea to focus on the retina like most laser beams. But I digress... The power needed to cut a material depends on the thickness, edge quality required, and speed required. Like welding, there are no clear rules, only general guidelines based on experience. 60W is not much power for laser cutting, and would be unlikely to make a clean edge on 1/4" plastic at any reasonable speed, or to give an acceptable cut on 3/8" material at all unless assisted by a compressed gas jet, which cheap and low-powered laser cutters do not use.
I happen to need some weird Delrin parts for a 1960s oscilloscope. My parts have cracks and Delrin is almost impossible to glue unless the surface is chemically prepared.
I wonder if Joshua can tell us if there's a way to prepare the surface correctly at home? And what specific adhesive works?
Nothing sticks WELL to Delrin/acetal. Epoxies can be used to bond it, but it's not recommended at all if any other means of connection is feasible. Its non-reactive and low-friction properties are directly related to its very low surface energy, which makes bonding work poorly. Acrylic is much better if you need to glue, since superglue (cyanoacrylate) bonds extremely well and matches its mechanical properties fairly well. Polycarbonate is also good.
I have an off-grid cabin on a mountaintop in the middle of nowhere. It's not a survival campsite, but it's quite remote. I can work from there if I need to, and I sometimes do. I have rainwater collection, solar power with plenty of storage, and line of sight to a cell tower on another peak several miles away. Full 4G data from all providers - but only once you're up on the peak, not on the way in. This is a reliable and comfortable way to work from a wilderness location. But this kind of system does not work for survival camping, especially moving between locations. Reliability requires a fixed location with line of sight data service, and a fixed solar installation. If your priority is primitive camping, I don't think this can be achieved effectively. But if your priority is to experience isolated wilderness while definitely staying connected, a small cabin (even a primitively constructed shelter) at a carefully chosen location can work just fine.
What happened to the legal standard that new laws cannot be applied ex post facto?
I don't understand how that relates to this situation. A prohibited ex post facto law is one which criminalizes or imposes a penalty for an act which occurred before the law was enacted. For example, a new law which raises your taxes for last year and makes you pay the difference now. Or a law which makes it a crime to have previously consumed alcohol before the law was passed. This does not seem related to the case at hand.
Wut?!?!
Per the decision:
The preliminary injunction entered by the district court is hereby vacated and the case remanded for such further proceedings as may be appropriate.
It doesn't overturn the previous finding that the program is unconstitutional - it makes it like that finding never existed in the first place.
That's not what that means. The appellate court vacated the preliminary injunction, they did not reverse a legal determination on constitutionality. As one of the other commenters noted, I actually oversimplified the ruling - they didn't even determine that the plaintiff definitely can't pursue the case, they just determined that he can't get a preliminary injunction because there aren't enough facts to support his standing yet.
"The appellate court explicitly did NOT "overturn" the district court's substantive finding that the program is unconstitutional. This ruling is procedural, and unrelated to the merits of the legal arguments about constitutionality of the NSA program."
+1 for that part of your comment.
"The court instead found that this particular plaintiff does not have standing to challenge the program in court."
-1 for that part of your comment. They didn't rule that he didn't have standing (well, 1 of the 3 judges did, but the majority did not), or that the trial can't proceed. They simply said that there's not enough evidence of standing shown in the pre-trial phase for an preliminary injunction (which they say requires a higher bar than the standing requirement needed to proceed with the trial). The trial can proceed, where more evidence can be obtained and presented.
BTW - the latest empytwheel.net post highlights some brand new evidence showing that the plaintiff has standing.
You're right. I oversimplified it. They found that, based on the record as it stands currently, there is not adequate evidence to show standing - but there might be later after more discovery. The case is not dismissed, the preliminary injunction is just denied.
The appellate court explicitly did NOT "overturn" the district court's substantive finding that the program is unconstitutional. This ruling is procedural, and unrelated to the merits of the legal arguments about constitutionality of the NSA program. The court instead found that this particular plaintiff does not have standing to challenge the program in court. It's a very problematic ruling, raises a lot of issues, and in my opinion should be reversed - but it certainly does not overturn the lower court's finding that the program is unconstitutional as a matter of law.
"web-scale data centers are designed to cope with hardware failures". So.... it's OK if you use my motherboard design and they randomly fail, because you should just make up for that in software or hardware redundancy? Um, no.
That's exactly what it means, and how it works. When you have tens of thousands of nodes, some of them WILL eventually fail during operation, no matter how good the hardware is. Thus, the software must be designed to accommodate hardware failures and seamlessly continue operation without interruption or data loss. If you already have to design the software to handle that anyway, then there is not much incentive to go to great lengths to improve hardware reliability. Whether the failure rate is 1:100000 or 1:1000 annually, the result is the same on the software side. But if the less reliable hardware is dramatically cheaper (which it is), then it makes more sense to use the cheap hardware and replace it more often.
If you're logged in and have good karma, you should be able to disable ads as a "courtesy" to dedicated contributors. Or just use an adblock extension.
This lawsuit is a legal mess, destined to fail. In fact, it already did fail and they're just trying futilely to revive it. All applicable statutes of limitations passed years ago. You can't wait decades to file a lawsuit. Equally as importantly, "The Marshall Islands" as a political subdivision does not have standing to sue for injuries that occurred to specific people and property there. Those people and property owners would have to sue, not their regional government. Finally, the decisions which were made and the actions taken were political decisions made by the United States in exercise of its sovereign authority - and you can't sue for that. It seems that the plaintiffs know this, which is why they are now trying to frame the lawsuit as a claim to enforce the NPT. The problem with that is, yet again, a lack of standing on several levels, and an inaccurate interpretation of the treaty itself. First, there is no cause of action through which any individual or entity can force the government to comply with or enforce a treaty. International relations are solely the sovereign domain of the federal government, and they can decide to abide by (or disregard) treaties as our elected officials see fit. Second, the treaty is not being violated. It does not require disarmament, nor is there a mandatory timeline for any particular disarmament-related activity. It says the signatories will negotiate towards an agreement regarding disarmament. That's not an enforceable mandate in any meaningful sense. Why? Because the signatories never actually had any intention of disarming, so they made an agreement that didn't require them to disarm. A third party can't come in and force them to abide by a deal they didn't make in the first place. Look, the Marshallese got screwed. There was a discriminatory component to that. It wouldn't happen the same way today. But the bottom line is that we needed a place to test weapons of mass destruction, and the Marshall Islands were the best choice available. So the US did what they had to do to make the program work. They should have provided market-based compensation for the taking of land, and they should have relocated everyone out of the zone of danger, turning the entire area into a restricted military installation before blowing it up repeatedly. There should have been no injuries and no uncompensated loss of property. But the reasonable conclusion to take away from those events is not that nuclear weapons should be eliminated, or that the tests shouldn't have been conducted at that location. They served a critical purpose for national security, and anyone who says otherwise is a revisionist with an agenda.
Ever since their first widespread implementations in the mid 20th century, turbopumps have been powered by rocket propellants - either the same stuff they are pumping (F1 engine in the Saturn V), or a separate propellant dedicated to powering the pumps (Space Shuttle Main Engines). There are excellent reasons for this, and not many good reasons to use batteries and motors instead. Rocket propellant pumps require truly massive amounts of power to move thousands of gallons per minute of propellants at thousands of PSI pressure. The SSME turbopumps require over 70,000 horsepower per engine. Like all other rocket hardware, size and weight are extreme concerns. Power-to-weight ratio is the single most critical design goal. Rocket engines themselves burn the propellants they do specifically because those chemical combinations are the absolute best we have for producing the maximum amount of thermo-mechanical energy from the least mass, no-compromise. Using the same types of propellants to drive the turbopumps also provides the maximum achievable power to weight ratio. The SSME turbopumps produce over 100HP per pound, which is insanely high. No known electric motor technology can even reach that order of magnitude in power density, even considering only the actual motor itself! There is no legitimate contest in performance between a gas-driven turbopump and any other technology besides nuclear, and that's that. To make such a large compromise in power to weight ratio by using electric pumps is very odd. Yes, gas-driven turbopumps are really hard. They are the hardest part of building a large liquid rocket engine. But those challenges were first solved over 60 years ago, and avoiding a tough engineering exercise is no excuse for making a giant compromise in performance. The extra mass of that electric drive system could be replaced with propellant or cargo.
http://en.wikipedia.org/wiki/M... Yes, IIAL (but not your lawyer), and no, going to the wrong car wash doesn't void your warranty. That's silly.