Employers must always assume that, any day, one of their employees will show up and announce their two-week notice. It's one of the risks of being in business and having employees at all.
On the flip side, they generally can fire their employees at will, too, so it's not entirely one-sided.
This is my major concern. Unless the textbooks are produced by salaried professions (i.e., not just those that have the expertise, but can also f*#king communicate and know how make a polished product), how to do you prevent the whole enterprise from being monopolized by ethusiastic, self-aggrandizing idiots that can't write their way out of a paper bag?
And while certain subjects (math, most of physics, most of biology and medicine) aren't particularly vulnerable to ideology, there are plenty of subjects (history (especially American history), economics, cosmology, evolution) that can't even be brought up in civilized conversation without the political and ideological aspects taking center stage. The controversial aspects have pedagogical value, but it's essential that those who shout loudest don't get to win by default.
Although people like to boast that their home sound system has hundreds or thousands of watts of power, the amount of power that goes into the speaker of a cellphone is quite small: tens of milliwatts is all that's needed to make it near deafening when you hold it next to your ear. Headphones require even less power: 10 mW or so. Processing power in standby mode is likewise quite small.
By contrast, depending on the local signal strength, the amount of power going into the radio circuits is measured in hundreds of milliwatts to several watts. There's not a whole lot that can be done with that, because improving it requires improving not only the cellphone, but also the whole cellphone network (deploying more sensitive cell tower receivers, or having more of them). That's a gradual process, and we've experienced enormous improvements since cellphones were introduced. But it's hardly the exponential process we've come to expect in electronic gadgetry. I don't know what the broadcast power of the early brick cellphones was back in the 1980s, but I suspect it was only on the order of ten watts (the FCC puts limits on these things, after all), not hundreds. Over the past few decades I suspect we've seen a linear decrease in average cellphone radio broadcast power, one that I expect has already started to approach an asymptotic limit.
Methinks he can get whatever he wants. Lots of high tech companies give him stuff gratis just to say that he's sporting their hardware. For example, from his website:
The computer is running on Windows XP. For many years it has been impossible to upgrade beyond Windows'98, because Professor Hawking's favourite speech software, Equalizer by Words-Plus, was made in 1986, and was designed to run only on DOS based operating systems. However, Intel has kindly funded the conversion of the software to XP. This involved Words-Plus re-writing the whole program for today’s operating system.
From other parts of his website, it looks like he has more than one system, or different configurations thereof, plus a van, and a house and workspace that's been tricked out to allow him a great deal of independence and mobility.
you haven't actually looked at the job description, have you?
The original purpose of this position was "to aid Professor Hawking in those areas which he has difficulty due to his disability." The job has since expanded and now includes:
Managing national and international travel for Prof. Hawking and his care team. Expect to spend around 3 months per year abroad!
* Development and maintenance of Professor Hawking's communication and speech systems
* Procurement and maintenance of his wheelchairs and accessible van
* Preparation of lecture graphics and public speaking
* Dealing with the media and press
* Answering inquiries from the public and maintaining the website
The post requires a wide range of skills, most importantly:
* Ability to work under pressure
* Maintenance of "black box" systems with no instruction manual or technical support
* Computer literacy
* Electronics knowledge
* Ability to speak to a large audience
* Ability to show others how to use complex systems
This is most definitely a full-time job, on his schedule. For the necessary skills, expected work, and unusual hours, the pay is pathetic. If you are doing maintenance on his system, expect to do a lot of it when he isn't using it (i.e., when he's sleeping, as in working 2nd and 3rd shift). I'm not saying it wouldn't be a cool job and have unquantifiable benefits more valuable than the actual salary, but it hardly counts as "$38k for a "johnny on the spot" maintenance and upgrades guy is a pretty good pay scale for P/T work".
Well, gosh, I guess we should all go home then. Time to die! Is that supposed to be some feeble excuse for not even trying? Some of us would like the chance, pretty please, to have a go at making the future less of a disaster. There's a difference between recognizing futility and acquiescing to it.
Sure, there will be sacrifice. And yes, all that sacrifice can't make it all better. But in the choice between struggling but not fully succeeding, and just giving up to failing utterly, I think most people would step up and do something. The difference between people acting like sheep, laying down to die, and those that stand and fight even in the face of futility is leadership and courage. Perhaps I'm misguided and naive in my hope that I may yet see some.
That the US had an extensive spy satellite program back in the day is hardly a conspiracy or secret: it was broadly known, even back then. The Soviets, certainly, knew it, as did large swaths of our own military and intelligence community. Even a good slice of the American public probably knew, or guessed, about such capabilities. Keeping tight-lipped about what you do each day isn't a secret of the same caliber as keeping the entire program secret.
Consider that a project like this was kept secret even though everyone keeping the secret had a clear conscience, their project never implicated in moral wrongs like torture, false flag invasion, inside job "Let It Happen On Purpose" self-sabotage or worse
Are you trying to argue that keeping it a secret was harder because it lacked moral ambiguity? Seems to me that lacking moral ambiguity makes it easier: takes away the whistleblower incentive. Easy to keep a secret when you see nothing (morally) wrong in the keeping of that secret.
Although the SR-71 was made to operate beyond the reach of fighter aircraft ans surface-to-air missiles, there was still the potential that it could be brought down, or malfunction and crash, over enemy territory. This carries a lot of risks.
In addition, the article mentions that a full-frame image from a KH-9 could cover an area over 300 miles across. That kind of wide-field view if important militarily in a way that complements the closer-up images from spy aircraft.
The SR-71 has a somewhat smaller radar cross-section than you'd expect for such a large aircraft, but it was hardly stealthy: the USSR and China could know exactly when they were overflown by it. They could also know pretty well when a spy satellite would be overhead of a certain area, but couldn't always be sure if it was taking photos during each pass. This meant that they always has to assume that their military sites were under continuous surveillance, even if they weren't, and expend significant resources to counteract that. Same, too, on our side.
Although the SR-71 could get most anywhere on the globe within a day, so long as the orbit inclination is right (they were mostly polar orbits, I would guess) you are pretty much guaranteed to have a satellite pass within 12-24 hours anyway. And once it is launched, the bird is always up there: you don't have to worry much about staging it the way you do with a limited number of aircraft. There may have been places too deep inside the USSR and China for the SR-71 or U-2 to reach.
So, in short, one could conclude that the military wanted a variety of intelligence gathering options for breadth, depth, redundancy, and theatrics. The fact that there was a lot of money available for such things, which could be spread across a lot of agencies and a congressional districts, probably didn't hurt, either. They didn't have to choose among options: they could opt to do them all.
Considering the cool stuff NASA was doing with Apollo there isn't an excuse for not having a moon base by now
Sure there is: the public got all starry-eyed at the Buck Rogers stuff and beating the Soviets to the Moon, then realized that this shit is really f*&king expensive and decided they had other priorities. Combine that with a general lack of long-term vision, leadership, and political will in government, and you have all the "excuse" you need. Everyone still expects wonders from NASA, and sometimes they get them, but the public generally doesn't want to pony up for it.
Unfortunately, the domain name that most closely corresponds to my own name is already taken. There is someone out there that has the same (none too common)name as me. He's a few decades older, with an established business in his own name, and first registered the domain in the mid 90s, before I was even in high school. Them's the breaks.
Absolutely no excuse for Gingrich's case. Amateur error.
Heat capacity is a major reason: a kilogram of water can absorb a whole lot more heat than a kilogram of cave air. So to cool off the same load, you need to transport (i.e., pump) a whole lot less water than you would air. It requires energy to do either one, so using cold water is more energy-efficient than using air. Plus, the required water pipes would be a whole lot smaller than the equivalent duct work for air.
Using water has difficulties, though, which may have been the reason this data center you mentioned didn't use it. Unless you have a really exotic setup, you don't cool the processors directly using sea water; you use the cold water to generate cold air, and blow the air across the racks. That extra step requires a beefy heat exchanger, which adds costs. The infrastructure to get and transport the water is also capital-intensive compared to just having a lot of big air intakes. At some scale (i.e., X megawatts of cooling load), water will still win out because it is such an efficient heat transport fluid compared to air.
I don't want to smack down what is probably a well-meaning suggestion, but it displays such profound ignorance...
Why do people persist in thinking that the dark side of the moon is, well, dark? I blame Pink Floyd. The far side of the moon receives just as much sunlight, on average, as the side facing Earth. So building a data center on the far side is, from a thermal standpoint, just as sensible as building it on the near side: completely ridiculous. It is actually really hard to dump heat into a vacuum. This would be true in cold black space far from the sun, but is doubly so when you spend a week or two out of every month out in full sunlight!
Building a datacenter on the far side of the moon is absurd for another reason: you would need a relay satellite for communications, probably many of them, because there is no line of sight from the far side to Earth. Even if you accept that you'll use a satellite, then you face the reality that a lunar satellite has, compared to terrestrial fiber, utterly horrible throughput (by a factor of 10,000) and a round-trip communication time of 2.5 seconds.
I wasn't talking about post-machining the whole part, just the places where it is important. In the example you linked to, the jet engine pivot, would likely still need post-machining operations to ensure that the bolt pattern on the flange would match up with the mating part, or that the main pivot point had a smooth round hole that would accept a bushing, bearing, shoulder bolt, whatever, and that the distance and angle between those two features was within tolerance.
Another example from my own experience: I had to design a manifold for a tiny pneumatic device. It needed convoluted internal passages, undercuts all over, random bosses at odd angles for mating parts - things that are easy to produce using rapid prototyping. In this case, it would have been abominable to try to produce any other way. But the manifold part also needed smooth bores for o-rings and valves, tapped holes for fasteners in just the right place, smooth planar surfaces for face gaskets - all things that can't be done with rapid prototyping. So we first grew the "raw part" then post-machined it. It's hard to think of any other way of producing this part that would have 1) allowed it to in the tiny and irregular form factor and, 2) been relatively inexpensive to produce.
It is true that additive processes can produce parts that couldn't be made otherwise. Your example shows that well. But in many cases, if not most, it doesn't obviate the need to post-machine critical features.
They're starting to use 3d printing in aircraft parts because they can print more complex, lighter and stronger shapes with the printers. This is being done with metal.
A lot of those printed parts are still machined after the fact, because in many cases you need smooth, flat, round, toleranced, etc. geometry to interface with with parts. Using 3D printing of metal is a faster and cheaper way of doing low-volume prototype and production than casting, but cast parts are rarely used straight-from-the-mold.
Some 3D printing solutions spread a layer of powder, then bind it together by selectively printing glue. Drop the stage by one layer, spread more powder, print binder, repeat. This is the technology used by Z-Corporation for their products.
In this case, you'd be sending up big tanks of binder, and using the abundant regolith of the moon to create solid objects.
Unfortunately, this would only be appropriate for making a small minority of the kinds of things you need on a lunar colony. You could use it to create blocks of arbitrary shape for use in structures (like legos or linkin' logs). Think of it as a way to print intricate concrete structures. If you got creative you could build very impressive structures: imagine how lofty a stone-built cathedral could be in 1/6th gravity! But for machinery it would totally suck: regolith is basically powdered volcanic glass and unweathered sand, and is abrasive as hell.
Back when NASA first started, information was hard to come by
Indeed, most of the information needed for spaceflight didn't exist when NASA was formed! That kind of R&D takes serious dollars - billions of dollars, even back then. (and to all those libertarians out there: it was government money, and in no small part government agencies and labs, that did that R&D.)
I wouldn't exactly say that all the necessary knowledge for building and launching a spacecraft is freely available even today, but it'll certainly be cheaper now that the knowledge actually exists!
It is utterly impractical to think that you could pre-screen user-generated content. Facebook has, what, 800 million users. How many millions of screeners would you need to sift through all the potential content out there - even if were solely restricted to India? How do you keep all those screeners from going braindead reading through all that stuff? How do you keep them from gouging their eyes out with the inane horror of it all. And, most importantly, how do you decide what gets censored, and enforce that it gets kept out?
"The wars of the future will not be fought on the battlefield or at sea. They will be fought in space, or possibly on top of a very tall mountain. In either case, most of the actual fighting will be done by small robots. And as you go forth today remember always your duty is clear: To build and maintain those robots."
the Fukushima plant was built before knowledge of tsunamis is as advanced as it is today, and that it had a degree of resilience built in against a "more normal" tsunami, rather than the absolute monster that did appear
Here is a counterpoint. Risk management is not a one-time thing: if you are in a risky business (be is security, medical safety, nuclear power, etc.), you need to continually re-assess what risks exist and whether you have properly mitigated them. Failure to take new knowledge, such as improved tsunami science, into account as it becomes available and act on it appropriately is simply negligent.
One thing that so many don't realize about the U.S. Congress, and particularly the Senate, is that so much of the bullshit that goes on has nothing to do with their constitutional duties to craft, debate, and revise legislation, but rather to the skirting and enforcing of procedural rules. I'm not talking about overly-civilized stuff like Robert's Rules of Order that keep everyone from shouting at the same time. These are rules that, for instance, allow a single disgruntled Senator to completely uphold the nomination process - such as this case. Sometimes the Senator has demands for such and such information (which may be valid), but usually it is just a veil for quid pro quo. Most egregious of these procedures is the anonymous hold, which allows otherwise qualified candidates to have their nomination in limbo, indefinitely, at the whim of some Senator so craven they won't even dignify their objection in public. The Senate is authorized to advise and consent on executive nominations, not to hide in the corner and pout like children.
at this point the limiting factor would be the fact that you need fantastically sensitive radio equipment to communicate with Voyager. At this point, only NASA's Deep Space Network can manage it. The Voyager transmitters are only about 20 W, and by the time it reaches Earth 10-12 hours later is down to about 10^-18 W (about -150 dB). You need large radio dish antennae and uniquely sensitive equipment to be able to receive that. On the transmit side, I've seen the number 20 kW bandied about, again with very large antennae that can direct that very precisely. Radio astronomers have sensitive dishes, but not many facilities also have transmit capabilities.
If someone wanted to built a competing Deep Space Network, they wouldn't be able to do keep it a secret. The infrastructure (i.e., the dish) would be conspicuous, as would the transmissions. Do something nefarious with it (like trying to hijack voyager) would probably result in a cruise missile up your ass. And even if you could hijack Voyager, why would you?
As long as you have fuel, you'll keep accelerating, albeit at a very small rate. It might take ten or twenty years, but I reckon that if an ESI probe was launched tomorrow it'd overtake Voyager and still have propellant to go faster.
All well and good, but how do you power it for a deep-space mission? Ion propulsion systems require 1000W - 10,000W of electrical input. You might be able to manage that at the beginning of the trip with solar panels, but solar incidence falls with the square of distance: at 1.4 AU you are already down to 1/2 power, at Jupiter you are down to just 4% of your original power. You could try using RTGs but, other than the fact that there are none available, even the most abundantly powered RTG craft ever - Cassini - had less than 1 kW of electrical output at launch.
We could cheaply launch 10's of much faster probes with incrementally better sensors for the price of the voyager program (~$3B in today's dollars)
you are off in your reckoning. We could perhaps launch a handful of small craft, but certainly not 10's. And although technology has progressed, the speed with which we can travel in the solar system hasn't changed much.
For comparison, the New Horizons mission to Pluto has an expected lifetime cost of about $650 million - and that is a very modest probe. If it were an Earth-sensing mission (leaving aside the RTGs vs. solar panels), the mission cost would probably be half that - chump change as satellites go. The additional cost comes in part from the need for a more powerful rocket, but also because there is so much added rigor in testing the spacecraft beforehand (all their eggs in one basket, so to speak), and because you need to employ an entire support staff for a decade before you even get there.
Another example is the recently launched Juno mission to Jupiter. That's a ~$1 billion mission (again, lifetime costs from inception through eventual death-plunge into Jupiter). The spacecraft itself is probably more expensive than would otherwise be expected because of all the radiation-hardening it needs (and testing that accompanies that). The spacecraft uses a huge (60 m^2) array of high-efficiency (triple junction GaAs, I would guess) solar panels for power, which may actually be more expensive than the conventional alternative of RTGs.
On the plus side, both of these spacecraft are amazing science platforms and will provide impressive results over their missions. New Horizons has already provided new data regarding Jupiter (flyby in 2007).
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Employers must always assume that, any day, one of their employees will show up and announce their two-week notice. It's one of the risks of being in business and having employees at all.
On the flip side, they generally can fire their employees at will, too, so it's not entirely one-sided.
Would you rather that the state continue to pay for new textbooks, over and over and over?
This is my major concern. Unless the textbooks are produced by salaried professions (i.e., not just those that have the expertise, but can also f*#king communicate and know how make a polished product), how to do you prevent the whole enterprise from being monopolized by ethusiastic, self-aggrandizing idiots that can't write their way out of a paper bag?
And while certain subjects (math, most of physics, most of biology and medicine) aren't particularly vulnerable to ideology, there are plenty of subjects (history (especially American history), economics, cosmology, evolution) that can't even be brought up in civilized conversation without the political and ideological aspects taking center stage. The controversial aspects have pedagogical value, but it's essential that those who shout loudest don't get to win by default.
Although people like to boast that their home sound system has hundreds or thousands of watts of power, the amount of power that goes into the speaker of a cellphone is quite small: tens of milliwatts is all that's needed to make it near deafening when you hold it next to your ear. Headphones require even less power: 10 mW or so. Processing power in standby mode is likewise quite small.
By contrast, depending on the local signal strength, the amount of power going into the radio circuits is measured in hundreds of milliwatts to several watts. There's not a whole lot that can be done with that, because improving it requires improving not only the cellphone, but also the whole cellphone network (deploying more sensitive cell tower receivers, or having more of them). That's a gradual process, and we've experienced enormous improvements since cellphones were introduced. But it's hardly the exponential process we've come to expect in electronic gadgetry. I don't know what the broadcast power of the early brick cellphones was back in the 1980s, but I suspect it was only on the order of ten watts (the FCC puts limits on these things, after all), not hundreds. Over the past few decades I suspect we've seen a linear decrease in average cellphone radio broadcast power, one that I expect has already started to approach an asymptotic limit.
From other parts of his website, it looks like he has more than one system, or different configurations thereof, plus a van, and a house and workspace that's been tricked out to allow him a great deal of independence and mobility.
This is most definitely a full-time job, on his schedule. For the necessary skills, expected work, and unusual hours, the pay is pathetic. If you are doing maintenance on his system, expect to do a lot of it when he isn't using it (i.e., when he's sleeping, as in working 2nd and 3rd shift). I'm not saying it wouldn't be a cool job and have unquantifiable benefits more valuable than the actual salary, but it hardly counts as "$38k for a "johnny on the spot" maintenance and upgrades guy is a pretty good pay scale for P/T work".
Well, gosh, I guess we should all go home then. Time to die! Is that supposed to be some feeble excuse for not even trying? Some of us would like the chance, pretty please, to have a go at making the future less of a disaster. There's a difference between recognizing futility and acquiescing to it.
Sure, there will be sacrifice. And yes, all that sacrifice can't make it all better. But in the choice between struggling but not fully succeeding, and just giving up to failing utterly, I think most people would step up and do something. The difference between people acting like sheep, laying down to die, and those that stand and fight even in the face of futility is leadership and courage. Perhaps I'm misguided and naive in my hope that I may yet see some.
Are you trying to argue that keeping it a secret was harder because it lacked moral ambiguity? Seems to me that lacking moral ambiguity makes it easier: takes away the whistleblower incentive. Easy to keep a secret when you see nothing (morally) wrong in the keeping of that secret.
Although the SR-71 was made to operate beyond the reach of fighter aircraft ans surface-to-air missiles, there was still the potential that it could be brought down, or malfunction and crash, over enemy territory. This carries a lot of risks.
In addition, the article mentions that a full-frame image from a KH-9 could cover an area over 300 miles across. That kind of wide-field view if important militarily in a way that complements the closer-up images from spy aircraft.
The SR-71 has a somewhat smaller radar cross-section than you'd expect for such a large aircraft, but it was hardly stealthy: the USSR and China could know exactly when they were overflown by it. They could also know pretty well when a spy satellite would be overhead of a certain area, but couldn't always be sure if it was taking photos during each pass. This meant that they always has to assume that their military sites were under continuous surveillance, even if they weren't, and expend significant resources to counteract that. Same, too, on our side.
Although the SR-71 could get most anywhere on the globe within a day, so long as the orbit inclination is right (they were mostly polar orbits, I would guess) you are pretty much guaranteed to have a satellite pass within 12-24 hours anyway. And once it is launched, the bird is always up there: you don't have to worry much about staging it the way you do with a limited number of aircraft. There may have been places too deep inside the USSR and China for the SR-71 or U-2 to reach.
So, in short, one could conclude that the military wanted a variety of intelligence gathering options for breadth, depth, redundancy, and theatrics. The fact that there was a lot of money available for such things, which could be spread across a lot of agencies and a congressional districts, probably didn't hurt, either. They didn't have to choose among options: they could opt to do them all.
Sure there is: the public got all starry-eyed at the Buck Rogers stuff and beating the Soviets to the Moon, then realized that this shit is really f*&king expensive and decided they had other priorities. Combine that with a general lack of long-term vision, leadership, and political will in government, and you have all the "excuse" you need. Everyone still expects wonders from NASA, and sometimes they get them, but the public generally doesn't want to pony up for it.
Unfortunately, the domain name that most closely corresponds to my own name is already taken. There is someone out there that has the same (none too common)name as me. He's a few decades older, with an established business in his own name, and first registered the domain in the mid 90s, before I was even in high school. Them's the breaks.
Absolutely no excuse for Gingrich's case. Amateur error.
Heat capacity is a major reason: a kilogram of water can absorb a whole lot more heat than a kilogram of cave air. So to cool off the same load, you need to transport (i.e., pump) a whole lot less water than you would air. It requires energy to do either one, so using cold water is more energy-efficient than using air. Plus, the required water pipes would be a whole lot smaller than the equivalent duct work for air.
Using water has difficulties, though, which may have been the reason this data center you mentioned didn't use it. Unless you have a really exotic setup, you don't cool the processors directly using sea water; you use the cold water to generate cold air, and blow the air across the racks. That extra step requires a beefy heat exchanger, which adds costs. The infrastructure to get and transport the water is also capital-intensive compared to just having a lot of big air intakes. At some scale (i.e., X megawatts of cooling load), water will still win out because it is such an efficient heat transport fluid compared to air.
I don't want to smack down what is probably a well-meaning suggestion, but it displays such profound ignorance...
Why do people persist in thinking that the dark side of the moon is, well, dark? I blame Pink Floyd. The far side of the moon receives just as much sunlight, on average, as the side facing Earth. So building a data center on the far side is, from a thermal standpoint, just as sensible as building it on the near side: completely ridiculous. It is actually really hard to dump heat into a vacuum. This would be true in cold black space far from the sun, but is doubly so when you spend a week or two out of every month out in full sunlight!
Building a datacenter on the far side of the moon is absurd for another reason: you would need a relay satellite for communications, probably many of them, because there is no line of sight from the far side to Earth. Even if you accept that you'll use a satellite, then you face the reality that a lunar satellite has, compared to terrestrial fiber, utterly horrible throughput (by a factor of 10,000) and a round-trip communication time of 2.5 seconds.
I wasn't talking about post-machining the whole part, just the places where it is important. In the example you linked to, the jet engine pivot, would likely still need post-machining operations to ensure that the bolt pattern on the flange would match up with the mating part, or that the main pivot point had a smooth round hole that would accept a bushing, bearing, shoulder bolt, whatever, and that the distance and angle between those two features was within tolerance.
Another example from my own experience: I had to design a manifold for a tiny pneumatic device. It needed convoluted internal passages, undercuts all over, random bosses at odd angles for mating parts - things that are easy to produce using rapid prototyping. In this case, it would have been abominable to try to produce any other way. But the manifold part also needed smooth bores for o-rings and valves, tapped holes for fasteners in just the right place, smooth planar surfaces for face gaskets - all things that can't be done with rapid prototyping. So we first grew the "raw part" then post-machined it. It's hard to think of any other way of producing this part that would have 1) allowed it to in the tiny and irregular form factor and, 2) been relatively inexpensive to produce.
It is true that additive processes can produce parts that couldn't be made otherwise. Your example shows that well. But in many cases, if not most, it doesn't obviate the need to post-machine critical features.
A lot of those printed parts are still machined after the fact, because in many cases you need smooth, flat, round, toleranced, etc. geometry to interface with with parts. Using 3D printing of metal is a faster and cheaper way of doing low-volume prototype and production than casting, but cast parts are rarely used straight-from-the-mold.
Some 3D printing solutions spread a layer of powder, then bind it together by selectively printing glue. Drop the stage by one layer, spread more powder, print binder, repeat. This is the technology used by Z-Corporation for their products.
In this case, you'd be sending up big tanks of binder, and using the abundant regolith of the moon to create solid objects.
Unfortunately, this would only be appropriate for making a small minority of the kinds of things you need on a lunar colony. You could use it to create blocks of arbitrary shape for use in structures (like legos or linkin' logs). Think of it as a way to print intricate concrete structures. If you got creative you could build very impressive structures: imagine how lofty a stone-built cathedral could be in 1/6th gravity! But for machinery it would totally suck: regolith is basically powdered volcanic glass and unweathered sand, and is abrasive as hell.
Is there a Ralph's around where you live? I hear coffee cans are great for transporting ashes.
Indeed, most of the information needed for spaceflight didn't exist when NASA was formed! That kind of R&D takes serious dollars - billions of dollars, even back then. (and to all those libertarians out there: it was government money, and in no small part government agencies and labs, that did that R&D.)
I wouldn't exactly say that all the necessary knowledge for building and launching a spacecraft is freely available even today, but it'll certainly be cheaper now that the knowledge actually exists!
It is utterly impractical to think that you could pre-screen user-generated content. Facebook has, what, 800 million users. How many millions of screeners would you need to sift through all the potential content out there - even if were solely restricted to India? How do you keep all those screeners from going braindead reading through all that stuff? How do you keep them from gouging their eyes out with the inane horror of it all. And, most importantly, how do you decide what gets censored, and enforce that it gets kept out?
"The wars of the future will not be fought on the battlefield or at sea. They will be fought in space, or possibly on top of a very tall mountain. In either case, most of the actual fighting will be done by small robots. And as you go forth today remember always your duty is clear: To build and maintain those robots."
The Secret War of Lisa Simpson, and amusing mashup
Here is a counterpoint. Risk management is not a one-time thing: if you are in a risky business (be is security, medical safety, nuclear power, etc.), you need to continually re-assess what risks exist and whether you have properly mitigated them. Failure to take new knowledge, such as improved tsunami science, into account as it becomes available and act on it appropriately is simply negligent.
One thing that so many don't realize about the U.S. Congress, and particularly the Senate, is that so much of the bullshit that goes on has nothing to do with their constitutional duties to craft, debate, and revise legislation, but rather to the skirting and enforcing of procedural rules. I'm not talking about overly-civilized stuff like Robert's Rules of Order that keep everyone from shouting at the same time. These are rules that, for instance, allow a single disgruntled Senator to completely uphold the nomination process - such as this case. Sometimes the Senator has demands for such and such information (which may be valid), but usually it is just a veil for quid pro quo. Most egregious of these procedures is the anonymous hold, which allows otherwise qualified candidates to have their nomination in limbo, indefinitely, at the whim of some Senator so craven they won't even dignify their objection in public. The Senate is authorized to advise and consent on executive nominations, not to hide in the corner and pout like children.
at this point the limiting factor would be the fact that you need fantastically sensitive radio equipment to communicate with Voyager. At this point, only NASA's Deep Space Network can manage it. The Voyager transmitters are only about 20 W, and by the time it reaches Earth 10-12 hours later is down to about 10^-18 W (about -150 dB). You need large radio dish antennae and uniquely sensitive equipment to be able to receive that. On the transmit side, I've seen the number 20 kW bandied about, again with very large antennae that can direct that very precisely. Radio astronomers have sensitive dishes, but not many facilities also have transmit capabilities.
If someone wanted to built a competing Deep Space Network, they wouldn't be able to do keep it a secret. The infrastructure (i.e., the dish) would be conspicuous, as would the transmissions. Do something nefarious with it (like trying to hijack voyager) would probably result in a cruise missile up your ass. And even if you could hijack Voyager, why would you?
All well and good, but how do you power it for a deep-space mission? Ion propulsion systems require 1000W - 10,000W of electrical input. You might be able to manage that at the beginning of the trip with solar panels, but solar incidence falls with the square of distance: at 1.4 AU you are already down to 1/2 power, at Jupiter you are down to just 4% of your original power. You could try using RTGs but, other than the fact that there are none available, even the most abundantly powered RTG craft ever - Cassini - had less than 1 kW of electrical output at launch.
you are off in your reckoning. We could perhaps launch a handful of small craft, but certainly not 10's. And although technology has progressed, the speed with which we can travel in the solar system hasn't changed much.
For comparison, the New Horizons mission to Pluto has an expected lifetime cost of about $650 million - and that is a very modest probe. If it were an Earth-sensing mission (leaving aside the RTGs vs. solar panels), the mission cost would probably be half that - chump change as satellites go. The additional cost comes in part from the need for a more powerful rocket, but also because there is so much added rigor in testing the spacecraft beforehand (all their eggs in one basket, so to speak), and because you need to employ an entire support staff for a decade before you even get there.
Another example is the recently launched Juno mission to Jupiter. That's a ~$1 billion mission (again, lifetime costs from inception through eventual death-plunge into Jupiter). The spacecraft itself is probably more expensive than would otherwise be expected because of all the radiation-hardening it needs (and testing that accompanies that). The spacecraft uses a huge (60 m^2) array of high-efficiency (triple junction GaAs, I would guess) solar panels for power, which may actually be more expensive than the conventional alternative of RTGs.
On the plus side, both of these spacecraft are amazing science platforms and will provide impressive results over their missions. New Horizons has already provided new data regarding Jupiter (flyby in 2007).