Even assuming we launch another 4000 satellites in the next 40 years that's $5 Billion a year. Now, you are going to save what percentage of that? Half? Say you can charge 2.5 billion a year, you have 10% profit, and so if I could build the facility and provide the technology to make satellites usable with it for say $20 billion it might be worth it. Obviously it isn't considered that cheap or low enough risk yet, and making satellites survive a 1000g launch is non-trivial (way non-trivial).
Yeah, whatever. Every dickhead on the net thinks he's some kind of expert. Show me some credentials Doc. You people simply don't grasp the situation. There are no radically new physics at low energies. It is very true that we don't understand the interior of the 'continent', but once you've circumnavigated the thing you can say with a pretty high degree of certainty there's no passage to India. Like it or not that is the situation we're in. Time machines, warp drive, vacuum energy, anti-gravity, etc are NOT POSSIBLE. That isn't a statement of denial of ignorance, it is a statement made from a position of understanding physics and the deep implications of what we observe in the world around us.
Are there potentially ways to say make anti-matter cheaply and efficiently? That's a possibility. Some tricks which could make fusion much easier? Yup, that's possible too. What you have to understand is that even with some technology like that manned spaceflight is always going to be horrendously expensive. Frankly I predict no manned space mission will ever leave near-Earth space. I know you'll hate to hear that, but all your wish-fulfillment fantasies won't make the space faerie come and bless you, nor the physics faerie either. Sorry.
Yeah, the Pentagon has outlined that design. The rough part is still the forces exerted on the payload at launch. It will work fine for an artillery shell, not so well for say a satellite. Still worth working on. The big issue will be finding a good reason to build a big one.
This is where it always starts to get rough. What is the application that will make it economically advantageous? By the time you spend the couple of 10's of billions to work out how to build a working production system, build it, and amortize the costs over the limited amount of space launch capacity we currently require it doesn't look great. I'd imagine we'd come up with applications, but there's not a vast motivation for anyone to invest in it. Space is a chicken-and-egg problem. Would easily be solvable with a bit of govt investment, except the 'bit' is a big heap of money in this case.
Yeah, that ain't anti-gravity, it is a nice diamagnetic effect, but don't expect land speeders and tie fighters anytime soon (as in ever).
Hydrogen balloons or aerostats/etc as have been proposed don't really solve the primary problem. You have to be traveling around 8,000 m/s to orbit the Earth, and that's essentially horizontal velocity, which being lofted on a balloon doesn't give you any extra of. Getting to say 200 km altitude straight up requires maybe 1/50th of the energy required for orbit. A balloon/air launch doesn't hurt, but it only reduces the size of the rocket required slightly.
We could launch stuff with a rail gun, but to launch a human into orbit using a railgun would require the gun to be something on the order of 1000 km long. You'd need several gigawatts of power as well, which probably means a couple small nuclear reactors. Again though, there are all kinds of unanswered questions about this kind of technology. We've built railguns that are maybe 1/10,000 of the size required. Scaling something up 4 orders of magnitude (while again dealing with huge power densities etc) ain't easy. Such a thing would likely cost as much as the whole ISS once you've spent the money to figure out HOW to build it. Launching hard cargo would be considerably easier but then you're talking about very high Gs. It may well simply not be economically worth it.
Yes, but there are large and almost entirely uncharacterized issues with even a 'sky hook'. It probably could be done, but even just the basics are a VERY steep engineering challenge. For instance in order to make the rendezvous happen at a reasonable relative velocity requires a great deal of control, and still requires materials of extraordinary strength. We have virtually no experience with these kinds of structures, and putting one in space would still require lifting a very substantial mass (and having the capability to service and refuel the drive system). First we will almost certainly require another couple of rounds of experience constructing things in orbit, another generation of rockets, better materials, etc. There may well be other serious issues we are unaware of.
In a sense it is a lot like building a large suspension bridge, except much bigger, assembled in orbit, etc. Many early bridges fell down, and that was an order of magnitude easier challenge. Even if we DID have such a technology it would only partially (at most) alleviate the cost.
Hybrid air-breathing engines are also a tough technology to develop. Some progress has been made but nobody has yet made anything even close to an actual transportation system and the R&D has been ongoing for more than 60 years. Again, something that will certainly happen. More decades and more billions will have to be spent on development. We're 30-40 years from having a really good working system IMNSHO. Things do get easier with better materials, control systems, and engineering/modeling etc.
Remember too, even a hybrid system will not be some routine flying like building a 747 and flying it around. You're talking about tremendous power densities, ultra-high temperatures, etc. Flying on a giant controlled explosion from standing start to Mach 11 in under 10 minutes will NEVER be cheap or routine.
Didn't I mention nuclear power? We're quite a long ways from convincing people that it would be wise to launch gigawatt scale thermal/nuclear power plants, nor have we really got a good design (yes, there are prototype designs that were developed in the 60's). It is not going to be easy to get that to happen, nor quick. Building really large scale propulsion lasers? Heh, they need to go in space, good luck.
Honestly, I've worked on rockets, you know, big ones that go into space, with people inside them even. ANYTHING you want off the Earth is going up on one of those. If it isn't going up on one of those it is going up using some machine with equal or greater power densities.
Rocket science isn't a synonym for REALLY HARD for nothing. Physics. You can't build a nuclear/thermal power plant with enough specific impulse to lift off in 1g. You still need rockets. In 100 years? Hard to say, but I'll firmly predict it still be pretty expensive and fundamentally new physics will play little, if any, part. Where it does appear it is going to be materials and control systems. There's no 'anti-gravity' hiding out there.
Forget it man, us fucktards are too stupid to understand...
Actually I put our situation with science like this. We're like late 18th century explorers. We KNOW the outline of the continents. Oh, there may still be an Australia out there we are only dimly aware of and there are MANY things yet to be discovered. Yet the basic outline IS known. Boundaries CAN be set on what is going to be possible. We'll find some neat tricks, maybe even good enough ones to venture off our planet one day, but they aren't going to set aside the laws we know now.
You can compare with 19th century classical physics etc all you want, but they really DIDN'T know enough to draw even the outlines.
Nobody is advocating giving up on doing science Mr Goobertoo. Please don't put words in my mouth, cheap rhetoric and name-calling? You're kidding yourself if you think you're impressing anyone that matters.
OK, so explain to me how you will get past the laws of physics then? Your statement is equivalent to "All you assholes that say perpetual motion can't be achieved are just pessimistic fucktards." Yeah, right...
Fundamentally the guy is correct. He may be incorrect in that we could build large nuclear powered VASIMIR / magnetohydrodynamic rockets, but those can't lift off from the Earth (insufficient specific impulse). Even if we built such a thing it only extends our range of action slightly. Someone might be able to go to Mars, but then you'll want to go further, and then you run into the real wall because Mars is nothing, that's like going next door. Nor is there anything particularly compelling about Mars. Antarctica is 1000's of times more habitable and nobody wants to live their either. As a target for a science mission? Sure.
Except that the molten Thorium salt fuel itself is very very dangerous. Residual decay heat is the problem, as with these BWRs. Once the salt gets OUT, which it will without coolant circulation, you have a water soluble and easily friable material which is intensely radiocative. It can either dissolve and be dispersed or disperse as a dust/powder with horrific consequences.
The notion that molten salt reactors are 'inherently safe' is a delusion. They are safer, up to a point. Once you go beyond that point they're vastly more dangerous. There ARE inherently safe fuel designs, thorium salt reactor is not one of them. You need a Uranium oxide based design, in which case you have solid ceramic fuel elements who's neutron capture ratio increases with temperature, allowing the reaction to stabilize at a reasonably safe thermal output under essentially all conditions. Even in this case there are potential radiation issues however. The higher the neutron flux from the reaction the more radioactive halides will be generated. These are short-lived isotopes but they are also rather biologically active (Iodine in particular), so there's really no such thing as an entirely safe scenario for ANY system. Still Uranium oxide ceramic fuel element designs are the best from a safety standpoint.
Reactors are just plain inherently dangerous machines. It is open to argument whether they're a better alternative than say coal, but any statements about inherently safe designs are significantly optimistic and ignore a number of failure pathways.
In any case, I'd venture to guess that we're finally about to see the death of the nuclear industry in the west. Policy makers would be wise to accept the inevitable and pour the billions of $ a year spent in this sector into more acceptable technologies. They can try to fight it, but it's a losing battle and a waste of time and energy at this point.
You're right, carbon aerogels, made by pyrolizing a formaldehyde polymer aerogel are used in super-capacitors. However this has nothing to do with carbon nanotubes. In fact there is no such thing as a carbon nanotube aerogel. There are bulk nanotube materials made by some sort of deposition process that are sometimes erroneously called 'aerogel', but they're not the same thing, nor do they have as far as I can determine any actual commercial use currently.
Again, the article was basically horribly inaccurate. Sloppy science reporting at best. Frankly I couldn't even find any indication that whatever the group being reported on is working on is actually anything new. There probably IS something new there, but whatever it was the article wasn't accurate enough to figure out what it was...
First of all aerogels are a whole class of materials. They aren't 'made from carbon nanotubes'. Obviously the aerogel they are working with contains carbon nanotubes, but aerogels can be made from MANY materials. You can make them from gelatin for that matter, though silica is the most common material (and what the highly insulating materials are generally based on).
In terms of battery/capacitor applications those are pure speculation. Add to the long list of possible ultra-capacitor and/or super-battery concepts. You can hardly walk into a materials lab nowadays without bumping into some guy that has an idea for a super-battery made from X.
The problem is you are all assuming that given IP X that my packets will go to the real X. That isn't what is going to happen. You can have as many root signed DNS responses as you want, all they tell you is what to put in your packet headers, they don't guarantee the traffic is actually going anywhere in particular. Thus DNS signing doesn't help you if the network is untrusted.
And if I can direct you to my fako proxy somewhere then all I need is to fool you enough. As long as I can get one CA to sign my cert that you trust then I can MITM you all day and all night. A client-side cert would defeat that see, because at least then the guy in the middle can't pretend to be the client to the server.
In the face untrusted networks you actually DO need client certs in order for your HTTPS to really guarantee anything. Passwords are not enough because once I'm in the middle of your conversation I can see all of that and you'll happily provide it. If both sides use a cert then SSL won't even happen with someone in the middle, barring actual faults in the protocol or implementation.
Assuming you ever get the real certs. At some level if the network is hostile you have to have some initial mutual authentication mechanism to even know what you are starting with. Is a root DNS key enough?
Well, large services such as Facebook could in theory simply issue their own client certs which are self-signed. It is more of an issue of it being a customer service issue than anything else.
SSL3/TLS will only protect against MITM attacks if BOTH the client AND the server mutually authenticate. This would require the issuance of a signed certificate to the client, not something that any garden variety retail grade web service does.
On the other hand it is quite possible that just using HTTPS would have thwarted the attack simply because it puts a rather higher technical barrier in place and makes it necessary to use more intrusive measures. In any case the point is a good one, HTTPS should be universal for any kind of authentication for a whole raft of reasons.
My comment would just be along the lines of what the DavidTC stated though, in the case where that kind of technology is warranted you're either in a huge organization with very specialized needs or well beyond the competency level of small shops.
It isn't so much a factor of being able to find a tool that could do the job. It is a matter that the various factors going into that kind of scale of system are so complex and varied. You need expertise in large scale mass storage, clustering, management, etc to back up something like that, and you're probably well into the realm of highly tweaked network, kernel, networking layer, etc. What you need is a dedicated team of experts. Something like Cassandra can be a great boon to them, but you better already have a very hefty IT budget or you're probably better off with vertical scaling and an RDBMS. You can go a LONG ways with that, trust me.
That we had all of this stuff 30 years ago. It was called 'network' databases, which were pretty much the standard sort of technology before RDBMS came along and everyone realized how incredibly much better relational algebra was for the vast majority of problems. As with many other things older ideas eventually resurface with new names and a few more features.
There are times when this kind of facility is useful. Nothing wrong with it. The vast majority of cases though where I've seen people using something like Cassandra or Big Table were ill advised. A properly optimized RDBMS with correctly designed schema can handle all but a few edge cases. Most of the hype these tools are generating is based on a lack of real understanding of how to properly use databases combined with people believing myths about other technologies and helped along by the industry's short memory span.
The best part though is that when something turns into a giant mess guys like me can make nice money fixing the mess. lol.
Well, maybe. You get into the question of levels of abstraction. I could easily enough design say a set of libraries that would let you do a lot of stuff in a given problem area with minimal code. The question is if such a high level abstraction will be a good solution. The more abstract the code you're working with the more likely it is to be inefficient or to lock you into choices that are awkward.
I think that's the main reason coding is still being done at basically the same level of abstraction it was 40 years ago. The only way we're going to write less code is to figure out ways to automatically generate output that is more sophisticated and more tuned to the specific problem. Code generators are really attempting to do that, just by inserting another layer of generated source between the coders and the compiler. It sort of works.
Eh, I would say that for the most part programmers have always wanted to just bypass all the hard stuff and do the coding. Nobody got into the business because they love specs! hehe.
There is just a lot of variation in the industry. Plenty of hackish code was written in the 80's and plenty of good stuff gets written now. The good stuff is just EXPENSIVE and well not everyone can afford it. If you're going to put code in a 747, it will cost $1000 bucks a line, easily (yes a terrible measure of coder productivity, but wc -l is easy to run).
Well, the team I run is all using modern tools, but still, each piece of business logic is defined as to what it will do, what inputs it will take, what behavior it will have for every set of inputs, what outputs it will generate in all those cases, any other considerations like transaction implications, etc.
By the time all of that is in place the LOGIC itself is pretty well known. There's really no room for asking "what do I do in this case" during coding. If you ARE asking those questions then it was a failure further up the chain in the process. There can be exceptions, but if you're coding and not totally clear on what the result is then it had better be a spike because the schedule impact isn't going to be well defined and iterations are pretty tight, no more than 2-3 weeks at most. Since no code is going to be complete and releasable without full unit tests (written first) as well as integration to the product build and runs through the functional test suite, review, etc. there's not a lot of time for asking questions at the coding stage.
So basically we're talking someone may spend 2 weeks writing 50-100 lines of code, possibly scattered about a couple modules and with some minor refactoring. Typing speed is just about the least relevant thing there is. Even if you can peck 10 WPM you're going to be coding for maybe 2-3 days out of that 2 weeks, total, and that includes writing the tests, which is usually maybe another couple 100 lines of code.
Of course we're not in a situation where there are bugs when you're done. There may be deficiencies in the code that are not relevant to the current iteration but it HAS to work, otherwise bad things happen and voices are raised in customer land. Back in my aerospace days it was even more extreme. A single coder often worked for weeks or a couple months on a single small module. Of course in THAT case you were dealing with "it works or airplanes fall out of the sky".
If you are talking about user stories, SRDs, TRDs, etc, then typing may be quite useful at some point. OTOH there are people for that, like managers (they have to be good for something, especially project managers, lol).
But it sounded like the guy was trying to say that good typing speed was useful for PROGRAMMING, lol. What I am really saying is 'typing in code is a very small part of the job'. It should basically be pretty rote because yes by the time you put things into code they should be designed already, the tests should be specced out, etc.
I don't know if that makes me "old school" or not. I came up in the 80's. The thing is really when you are entering source code you aught to generally know pretty much what it will look like. There's plenty of 'tradecraft' in writing nice code, but the importance of coding is vastly overestimated, and as a result most software is crap these days.
I mean there's stuff I wrote that is keeping 747's in the air and such, large high volume trading systems, etc. Maybe for your average home project things are different, but no commercial software should really be getting written at a text editor or IDE to any appreciable extent.
If you're spending most of your time as a programmer typing, or even dealing directly with source code, then there's a lot more wrong with this picture than typing speed. Keying in code should be one of the most trivial parts of the job.
I'd say being able to type well will probably improve ones enjoyment. It may save a few minutes here and there. It is certainly annoying to watch someone else type slowly when you're waiting on something. Still, it has little or nothing to do with one's ability to program or ability to complete coding tasks quickly and well.
Yeah. Apparently a couple millimeter wide crack is ENOUGH, lol. Those SRMs were an abomination. Just seeing them even considering SRMs for Constellation was enough to tell me it would never fly. They really are NOT safe.
Yeah, basically. However SRMs are incredibly reliable in terms of lighting off. They are crap in many other respects, but I can't think of an instance where a vehicle launched from a pad like the shuttle had an ignition failure in an SRB.
Basically the drill is at T - 6 the SSMEs start. At that point it is still possible to abort. Once all 3 SSMEs are running at full power the clock hits 0, something like 6 pyro igniters in each SRM fires them up, and then maybe 500ms later the hold down bolts blow.
As for range safety, the RSO is basically 'finger on button' during launch. It probably would take a half a second or something to flip up the cap and push the button. There's no automatic way, or accidental way those can go off. The self destruct basically blows a couple holes in the top of the SRM, at which point it will go completely to pieces on its own. Interestingly I actually worked on the box responsible for this stuff. It is pretty impressive. Made out of a 12"x12" brick of aluminum, hogged out to form a case, with some boards mounted in slots in the aluminum, and then the whole thing is potted full of engineering epoxy. It is basically the one 100.00000% reliability subsystem on the whole stack. The spec is basically "this cannot fail, period". Designing it and verifying it met spec was a pretty interesting project.
If that's what it takes, yup. Damned straight. Got an alternative suggestion? Going to go ask pretty please? lol.
Truthfully, there are probably much better solutions. We're obviously never going to get to them until certain people are made to understand that they aren't going to hide shit anymore, then we can have an intelligent and measured approach. The status quo is unacceptable. This is a new age and some people may have to be dragged kicking and screaming into it. That's exactly what is going on here. It ain't pretty but it IS necessary.
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Even assuming we launch another 4000 satellites in the next 40 years that's $5 Billion a year. Now, you are going to save what percentage of that? Half? Say you can charge 2.5 billion a year, you have 10% profit, and so if I could build the facility and provide the technology to make satellites usable with it for say $20 billion it might be worth it. Obviously it isn't considered that cheap or low enough risk yet, and making satellites survive a 1000g launch is non-trivial (way non-trivial).
Yeah, whatever. Every dickhead on the net thinks he's some kind of expert. Show me some credentials Doc. You people simply don't grasp the situation. There are no radically new physics at low energies. It is very true that we don't understand the interior of the 'continent', but once you've circumnavigated the thing you can say with a pretty high degree of certainty there's no passage to India. Like it or not that is the situation we're in. Time machines, warp drive, vacuum energy, anti-gravity, etc are NOT POSSIBLE. That isn't a statement of denial of ignorance, it is a statement made from a position of understanding physics and the deep implications of what we observe in the world around us.
Are there potentially ways to say make anti-matter cheaply and efficiently? That's a possibility. Some tricks which could make fusion much easier? Yup, that's possible too. What you have to understand is that even with some technology like that manned spaceflight is always going to be horrendously expensive. Frankly I predict no manned space mission will ever leave near-Earth space. I know you'll hate to hear that, but all your wish-fulfillment fantasies won't make the space faerie come and bless you, nor the physics faerie either. Sorry.
Yeah, the Pentagon has outlined that design. The rough part is still the forces exerted on the payload at launch. It will work fine for an artillery shell, not so well for say a satellite. Still worth working on. The big issue will be finding a good reason to build a big one.
This is where it always starts to get rough. What is the application that will make it economically advantageous? By the time you spend the couple of 10's of billions to work out how to build a working production system, build it, and amortize the costs over the limited amount of space launch capacity we currently require it doesn't look great. I'd imagine we'd come up with applications, but there's not a vast motivation for anyone to invest in it. Space is a chicken-and-egg problem. Would easily be solvable with a bit of govt investment, except the 'bit' is a big heap of money in this case.
Yeah, that ain't anti-gravity, it is a nice diamagnetic effect, but don't expect land speeders and tie fighters anytime soon (as in ever).
Hydrogen balloons or aerostats/etc as have been proposed don't really solve the primary problem. You have to be traveling around 8,000 m/s to orbit the Earth, and that's essentially horizontal velocity, which being lofted on a balloon doesn't give you any extra of. Getting to say 200 km altitude straight up requires maybe 1/50th of the energy required for orbit. A balloon/air launch doesn't hurt, but it only reduces the size of the rocket required slightly.
We could launch stuff with a rail gun, but to launch a human into orbit using a railgun would require the gun to be something on the order of 1000 km long. You'd need several gigawatts of power as well, which probably means a couple small nuclear reactors. Again though, there are all kinds of unanswered questions about this kind of technology. We've built railguns that are maybe 1/10,000 of the size required. Scaling something up 4 orders of magnitude (while again dealing with huge power densities etc) ain't easy. Such a thing would likely cost as much as the whole ISS once you've spent the money to figure out HOW to build it. Launching hard cargo would be considerably easier but then you're talking about very high Gs. It may well simply not be economically worth it.
Yes, but there are large and almost entirely uncharacterized issues with even a 'sky hook'. It probably could be done, but even just the basics are a VERY steep engineering challenge. For instance in order to make the rendezvous happen at a reasonable relative velocity requires a great deal of control, and still requires materials of extraordinary strength. We have virtually no experience with these kinds of structures, and putting one in space would still require lifting a very substantial mass (and having the capability to service and refuel the drive system). First we will almost certainly require another couple of rounds of experience constructing things in orbit, another generation of rockets, better materials, etc. There may well be other serious issues we are unaware of.
In a sense it is a lot like building a large suspension bridge, except much bigger, assembled in orbit, etc. Many early bridges fell down, and that was an order of magnitude easier challenge. Even if we DID have such a technology it would only partially (at most) alleviate the cost.
Hybrid air-breathing engines are also a tough technology to develop. Some progress has been made but nobody has yet made anything even close to an actual transportation system and the R&D has been ongoing for more than 60 years. Again, something that will certainly happen. More decades and more billions will have to be spent on development. We're 30-40 years from having a really good working system IMNSHO. Things do get easier with better materials, control systems, and engineering/modeling etc.
Remember too, even a hybrid system will not be some routine flying like building a 747 and flying it around. You're talking about tremendous power densities, ultra-high temperatures, etc. Flying on a giant controlled explosion from standing start to Mach 11 in under 10 minutes will NEVER be cheap or routine.
Didn't I mention nuclear power? We're quite a long ways from convincing people that it would be wise to launch gigawatt scale thermal/nuclear power plants, nor have we really got a good design (yes, there are prototype designs that were developed in the 60's). It is not going to be easy to get that to happen, nor quick. Building really large scale propulsion lasers? Heh, they need to go in space, good luck.
Honestly, I've worked on rockets, you know, big ones that go into space, with people inside them even. ANYTHING you want off the Earth is going up on one of those. If it isn't going up on one of those it is going up using some machine with equal or greater power densities.
Rocket science isn't a synonym for REALLY HARD for nothing. Physics. You can't build a nuclear/thermal power plant with enough specific impulse to lift off in 1g. You still need rockets. In 100 years? Hard to say, but I'll firmly predict it still be pretty expensive and fundamentally new physics will play little, if any, part. Where it does appear it is going to be materials and control systems. There's no 'anti-gravity' hiding out there.
Forget it man, us fucktards are too stupid to understand...
Actually I put our situation with science like this. We're like late 18th century explorers. We KNOW the outline of the continents. Oh, there may still be an Australia out there we are only dimly aware of and there are MANY things yet to be discovered. Yet the basic outline IS known. Boundaries CAN be set on what is going to be possible. We'll find some neat tricks, maybe even good enough ones to venture off our planet one day, but they aren't going to set aside the laws we know now.
You can compare with 19th century classical physics etc all you want, but they really DIDN'T know enough to draw even the outlines.
Nobody is advocating giving up on doing science Mr Goobertoo. Please don't put words in my mouth, cheap rhetoric and name-calling? You're kidding yourself if you think you're impressing anyone that matters.
OK, so explain to me how you will get past the laws of physics then? Your statement is equivalent to "All you assholes that say perpetual motion can't be achieved are just pessimistic fucktards." Yeah, right...
Fundamentally the guy is correct. He may be incorrect in that we could build large nuclear powered VASIMIR / magnetohydrodynamic rockets, but those can't lift off from the Earth (insufficient specific impulse). Even if we built such a thing it only extends our range of action slightly. Someone might be able to go to Mars, but then you'll want to go further, and then you run into the real wall because Mars is nothing, that's like going next door. Nor is there anything particularly compelling about Mars. Antarctica is 1000's of times more habitable and nobody wants to live their either. As a target for a science mission? Sure.
Except that the molten Thorium salt fuel itself is very very dangerous. Residual decay heat is the problem, as with these BWRs. Once the salt gets OUT, which it will without coolant circulation, you have a water soluble and easily friable material which is intensely radiocative. It can either dissolve and be dispersed or disperse as a dust/powder with horrific consequences.
The notion that molten salt reactors are 'inherently safe' is a delusion. They are safer, up to a point. Once you go beyond that point they're vastly more dangerous. There ARE inherently safe fuel designs, thorium salt reactor is not one of them. You need a Uranium oxide based design, in which case you have solid ceramic fuel elements who's neutron capture ratio increases with temperature, allowing the reaction to stabilize at a reasonably safe thermal output under essentially all conditions. Even in this case there are potential radiation issues however. The higher the neutron flux from the reaction the more radioactive halides will be generated. These are short-lived isotopes but they are also rather biologically active (Iodine in particular), so there's really no such thing as an entirely safe scenario for ANY system. Still Uranium oxide ceramic fuel element designs are the best from a safety standpoint.
Reactors are just plain inherently dangerous machines. It is open to argument whether they're a better alternative than say coal, but any statements about inherently safe designs are significantly optimistic and ignore a number of failure pathways.
In any case, I'd venture to guess that we're finally about to see the death of the nuclear industry in the west. Policy makers would be wise to accept the inevitable and pour the billions of $ a year spent in this sector into more acceptable technologies. They can try to fight it, but it's a losing battle and a waste of time and energy at this point.
You're right, carbon aerogels, made by pyrolizing a formaldehyde polymer aerogel are used in super-capacitors. However this has nothing to do with carbon nanotubes. In fact there is no such thing as a carbon nanotube aerogel. There are bulk nanotube materials made by some sort of deposition process that are sometimes erroneously called 'aerogel', but they're not the same thing, nor do they have as far as I can determine any actual commercial use currently.
Again, the article was basically horribly inaccurate. Sloppy science reporting at best. Frankly I couldn't even find any indication that whatever the group being reported on is working on is actually anything new. There probably IS something new there, but whatever it was the article wasn't accurate enough to figure out what it was...
First of all aerogels are a whole class of materials. They aren't 'made from carbon nanotubes'. Obviously the aerogel they are working with contains carbon nanotubes, but aerogels can be made from MANY materials. You can make them from gelatin for that matter, though silica is the most common material (and what the highly insulating materials are generally based on).
In terms of battery/capacitor applications those are pure speculation. Add to the long list of possible ultra-capacitor and/or super-battery concepts. You can hardly walk into a materials lab nowadays without bumping into some guy that has an idea for a super-battery made from X.
The problem is you are all assuming that given IP X that my packets will go to the real X. That isn't what is going to happen. You can have as many root signed DNS responses as you want, all they tell you is what to put in your packet headers, they don't guarantee the traffic is actually going anywhere in particular. Thus DNS signing doesn't help you if the network is untrusted.
And if I can direct you to my fako proxy somewhere then all I need is to fool you enough. As long as I can get one CA to sign my cert that you trust then I can MITM you all day and all night. A client-side cert would defeat that see, because at least then the guy in the middle can't pretend to be the client to the server.
In the face untrusted networks you actually DO need client certs in order for your HTTPS to really guarantee anything. Passwords are not enough because once I'm in the middle of your conversation I can see all of that and you'll happily provide it. If both sides use a cert then SSL won't even happen with someone in the middle, barring actual faults in the protocol or implementation.
Assuming you ever get the real certs. At some level if the network is hostile you have to have some initial mutual authentication mechanism to even know what you are starting with. Is a root DNS key enough?
Well, large services such as Facebook could in theory simply issue their own client certs which are self-signed. It is more of an issue of it being a customer service issue than anything else.
SSL3/TLS will only protect against MITM attacks if BOTH the client AND the server mutually authenticate. This would require the issuance of a signed certificate to the client, not something that any garden variety retail grade web service does. On the other hand it is quite possible that just using HTTPS would have thwarted the attack simply because it puts a rather higher technical barrier in place and makes it necessary to use more intrusive measures. In any case the point is a good one, HTTPS should be universal for any kind of authentication for a whole raft of reasons.
My comment would just be along the lines of what the DavidTC stated though, in the case where that kind of technology is warranted you're either in a huge organization with very specialized needs or well beyond the competency level of small shops. It isn't so much a factor of being able to find a tool that could do the job. It is a matter that the various factors going into that kind of scale of system are so complex and varied. You need expertise in large scale mass storage, clustering, management, etc to back up something like that, and you're probably well into the realm of highly tweaked network, kernel, networking layer, etc. What you need is a dedicated team of experts. Something like Cassandra can be a great boon to them, but you better already have a very hefty IT budget or you're probably better off with vertical scaling and an RDBMS. You can go a LONG ways with that, trust me.
That we had all of this stuff 30 years ago. It was called 'network' databases, which were pretty much the standard sort of technology before RDBMS came along and everyone realized how incredibly much better relational algebra was for the vast majority of problems. As with many other things older ideas eventually resurface with new names and a few more features. There are times when this kind of facility is useful. Nothing wrong with it. The vast majority of cases though where I've seen people using something like Cassandra or Big Table were ill advised. A properly optimized RDBMS with correctly designed schema can handle all but a few edge cases. Most of the hype these tools are generating is based on a lack of real understanding of how to properly use databases combined with people believing myths about other technologies and helped along by the industry's short memory span. The best part though is that when something turns into a giant mess guys like me can make nice money fixing the mess. lol.
Well, maybe. You get into the question of levels of abstraction. I could easily enough design say a set of libraries that would let you do a lot of stuff in a given problem area with minimal code. The question is if such a high level abstraction will be a good solution. The more abstract the code you're working with the more likely it is to be inefficient or to lock you into choices that are awkward.
I think that's the main reason coding is still being done at basically the same level of abstraction it was 40 years ago. The only way we're going to write less code is to figure out ways to automatically generate output that is more sophisticated and more tuned to the specific problem. Code generators are really attempting to do that, just by inserting another layer of generated source between the coders and the compiler. It sort of works.
Eh, I would say that for the most part programmers have always wanted to just bypass all the hard stuff and do the coding. Nobody got into the business because they love specs! hehe.
There is just a lot of variation in the industry. Plenty of hackish code was written in the 80's and plenty of good stuff gets written now. The good stuff is just EXPENSIVE and well not everyone can afford it. If you're going to put code in a 747, it will cost $1000 bucks a line, easily (yes a terrible measure of coder productivity, but wc -l is easy to run).
Well, the team I run is all using modern tools, but still, each piece of business logic is defined as to what it will do, what inputs it will take, what behavior it will have for every set of inputs, what outputs it will generate in all those cases, any other considerations like transaction implications, etc.
By the time all of that is in place the LOGIC itself is pretty well known. There's really no room for asking "what do I do in this case" during coding. If you ARE asking those questions then it was a failure further up the chain in the process. There can be exceptions, but if you're coding and not totally clear on what the result is then it had better be a spike because the schedule impact isn't going to be well defined and iterations are pretty tight, no more than 2-3 weeks at most. Since no code is going to be complete and releasable without full unit tests (written first) as well as integration to the product build and runs through the functional test suite, review, etc. there's not a lot of time for asking questions at the coding stage.
So basically we're talking someone may spend 2 weeks writing 50-100 lines of code, possibly scattered about a couple modules and with some minor refactoring. Typing speed is just about the least relevant thing there is. Even if you can peck 10 WPM you're going to be coding for maybe 2-3 days out of that 2 weeks, total, and that includes writing the tests, which is usually maybe another couple 100 lines of code.
Of course we're not in a situation where there are bugs when you're done. There may be deficiencies in the code that are not relevant to the current iteration but it HAS to work, otherwise bad things happen and voices are raised in customer land. Back in my aerospace days it was even more extreme. A single coder often worked for weeks or a couple months on a single small module. Of course in THAT case you were dealing with "it works or airplanes fall out of the sky".
If you are talking about user stories, SRDs, TRDs, etc, then typing may be quite useful at some point. OTOH there are people for that, like managers (they have to be good for something, especially project managers, lol).
But it sounded like the guy was trying to say that good typing speed was useful for PROGRAMMING, lol. What I am really saying is 'typing in code is a very small part of the job'. It should basically be pretty rote because yes by the time you put things into code they should be designed already, the tests should be specced out, etc.
I don't know if that makes me "old school" or not. I came up in the 80's. The thing is really when you are entering source code you aught to generally know pretty much what it will look like. There's plenty of 'tradecraft' in writing nice code, but the importance of coding is vastly overestimated, and as a result most software is crap these days.
I mean there's stuff I wrote that is keeping 747's in the air and such, large high volume trading systems, etc. Maybe for your average home project things are different, but no commercial software should really be getting written at a text editor or IDE to any appreciable extent.
If you're spending most of your time as a programmer typing, or even dealing directly with source code, then there's a lot more wrong with this picture than typing speed. Keying in code should be one of the most trivial parts of the job.
I'd say being able to type well will probably improve ones enjoyment. It may save a few minutes here and there. It is certainly annoying to watch someone else type slowly when you're waiting on something. Still, it has little or nothing to do with one's ability to program or ability to complete coding tasks quickly and well.
Yeah. Apparently a couple millimeter wide crack is ENOUGH, lol. Those SRMs were an abomination. Just seeing them even considering SRMs for Constellation was enough to tell me it would never fly. They really are NOT safe.
Yeah, basically. However SRMs are incredibly reliable in terms of lighting off. They are crap in many other respects, but I can't think of an instance where a vehicle launched from a pad like the shuttle had an ignition failure in an SRB.
Basically the drill is at T - 6 the SSMEs start. At that point it is still possible to abort. Once all 3 SSMEs are running at full power the clock hits 0, something like 6 pyro igniters in each SRM fires them up, and then maybe 500ms later the hold down bolts blow.
As for range safety, the RSO is basically 'finger on button' during launch. It probably would take a half a second or something to flip up the cap and push the button. There's no automatic way, or accidental way those can go off. The self destruct basically blows a couple holes in the top of the SRM, at which point it will go completely to pieces on its own. Interestingly I actually worked on the box responsible for this stuff. It is pretty impressive. Made out of a 12"x12" brick of aluminum, hogged out to form a case, with some boards mounted in slots in the aluminum, and then the whole thing is potted full of engineering epoxy. It is basically the one 100.00000% reliability subsystem on the whole stack. The spec is basically "this cannot fail, period". Designing it and verifying it met spec was a pretty interesting project.
If that's what it takes, yup. Damned straight. Got an alternative suggestion? Going to go ask pretty please? lol.
Truthfully, there are probably much better solutions. We're obviously never going to get to them until certain people are made to understand that they aren't going to hide shit anymore, then we can have an intelligent and measured approach. The status quo is unacceptable. This is a new age and some people may have to be dragged kicking and screaming into it. That's exactly what is going on here. It ain't pretty but it IS necessary.