(as a tanent: using more advanced warhead designs than the previous ones they replace too, so nonproliferation/stockpile-reduction in this case is a very generous casting).
I had a friend who as a translator on one of the old nuclear weapons and delivery systems stockpile reduction treaties with the old USSR before its collapse. She referred to the treaties as a scam because both sides wanted to get rid of their old weapons anyway, and this was just a way for each of them to get some positive PR out of it.
She also had an idea that she presented to... I forget what it was, but I think he was the Soviet equivalent of a colonel. She and some colleagues found it tragic to see these valuable, brilliant pieces of technology, the ballistic delivery systems, just being crushed by bulldozers. So they concocted a (largely tongue-in-cheek) plan to retrofit them into intercontinental pizza delivery systems, and did all of the design work and calculations for fun. You'd have to modify the heat shield and the reentry beta, as well as install proper racks to keep the pizzas in place, and an off-the-shelf spacecraft parachute system. You launch them frozen and they'd come out properly baked. Delivery to anywhere in the world, no matter how remote, in half an hour or so; the cost of the retrofits would make the delivery charge something like $20 per pizza (assuming you ordered a warhead full of them).
Unsurprisingly, the guy looked at them like they were crazy;)
All the commercial reactors in the US are light water (normal H20) and countries that use heavy water (Canada) may not be interested in stockpiling tritium.
I'm sure Canada is up for the challenge; they have a real can-du attitude.;)
It's the same as the situation with indium. Indium is found in conjunction with most copper, lead, tin, etc ores. However, there's historically been such a low demand for indium that just a couple mines had recovery circuits. And right as indium demand started to rise, one of the mines went out of business as its primary ore was no longer economical. So indium prices went through the roof in 2004/2005. Of course, that triggers more mines to install recovery circuits, but it takes time to get a new recovery circuit online.
"Just get it from the moon" -- as though it doesn't cost $5-15k per kilogram just to get a *vehicle* into *low earth orbit*. Let alone the surface of the moon. Let alone a return trip to the moon. Let alone a return trip to the moon and hauling enough manpower and equipment to mine the moon. For something that's found in parts-per-billion quantities, mixed in with parts-per-million quantities of something that's essentially chemically identical (He-4).
It's way, way easier to produce He3 here on earth; it's a decay product of tritium, which is bred from lithium which is exposed to a neutron flux (aka, a lithium blanket in a nuclear reactor). Which is why it was a byproduct of our thermonuclear weapon stockpile; as they sit, their tritium slowly decays.
Helium-3 is a *byproduct* of the *existence* of hydrogen bombs. More specifically, byproduct of the existence of tritium. Tritium decays into helium-3. Helium-3 was unwanted, while tritium was wanted; there were actually some projects to attempt to convert the helium-3 back into tritium.
This shortage has absolutely nothing to do with how easy or hard helium-3 is to produce or acquire, nor is it a testament to how "free market planning" works so much better than central planning. Quite the opposite, this is a well known phenomenon of free markets: products which are of lower value and which are produced in a limited number of places as a byproduct of producing a more valuable goods can be extremely vulnerable to price swings.
I can't help but feel that this proposal was designed by the good folks at Aperture Science;) I mean, seriously -- you really feel the need to teach satellites to read english just to avoid collisions? Was I not the only one who immediately pictured:
----- x Defense Logistics Agency solicits bids for development of fuel icing inhibitor (FSII) x Black Mesa FSII proposal: x x Costly: Black Mesa personnel overpaid given limited skillset/ambition. x x Design inhibits ice, nothing more x Aperture Proposal: x x Less expensive x x Bonus to DLA: Aperture FSII inhibits ice but is also : x x x A fully functional Disk Operating System x x x Arguably alive -----
Also, this quote, from elsewhere:
----- "When someone says 'I want a programming language in which I need only say what I wish done,' give them a lollipop." -----
What makes you think that we don't just give the most statistically likely answer because of many similar sentences (or more accurately, concepts) in our mental "database"? What makes you so sure that what Watson is doing is really so fundamentally different from what we do? Our brains don't work via fairy dust and rainbows; it's not magic.
Your "cow is to grass" example is actually a relatively simple challenge in AI. Lots of things really complicate it. Understanding human motivations, for example, requires a lot more than just a basic dictionary relationship of what powers what:
"Johnny wanted some money, so he bought a gun, walked into a store, and asked the clerk for money. The clerk gave him money. Why did the clerk give him money?"
Or parsing multiple contradictory concepts, which require that you be able to accept contradictory facts as true in different contexts:
* Dracula is a vampire.
* There is no such thing as a vampire.
* Dracula resides in Transylvania.
* Dracula does not reside in Transylvania.
* Dracula is immortal.
* Nothing is immortal.
Etc. All true statements in their own context. And there can be an arbitrary number of contexts. Think, for example, of the question, "What happens to you when you die?" All contexts would generally accept a physical description of your body's decay, but different religious contexts would have all sorts of statements which are "true" within their context but "false" in many others.
Watson's answer was completely correct -- it just didn't elaborate enough. There are various degrees of specificity one could use:
* Leg * Missing a leg * Missing a left leg * A prosthesis in place of a missing left leg * A wooden prosthesis in place of a missing left leg
And so on. All of these are correct; it's just varying degrees of specificity. And I have no doubt that Watson had the information available and processed to provide all of those answers, had it simply been instructed to be a bit less laconic with its answers. The same thing will apply to other uses for Watson. For example, they mentioned that they want to use it for medical applications. Well, in response to, "What is the source of this woman's infertility?", the answers, with varying degrees of specificity, could be:
* Uterus * Missing a uterus * Mullerian agenesis * Missing a uterus due to mullerian agenesis * WNT4 * WNT4 gene * A defective WNT4 * A defective WNT4 gene * Missing a uterus due to WNT4 * Missing a uterus due to WNT4 gene * Missing a uterus due to a defective WNT4 * Missing a uterus due to a defective WNT4 gene * Mullerian agenesis due to WNT4 * Mullerian agenesis due to WNT4 gene * Mullerian agenesis due to a defective WNT4 * Mullerian agenesis due to a defective WNT4 gene * Missing a uterus due to mullerian agenesis due to WNT4 * Missing a uterus due to mullerian agenesis due to WNT4 gene * Missing a uterus due to mullerian agenesis due to a defective WNT4 * Missing a uterus due to mullerian agenesis due to a defective WNT4 gene * All of the above with details on why the WNT4 gene is defective
And so on. What's the right answer? It depends on the context. Are you filling out an insurance form or working on a peer-reviewed paper? And even humans judge the right answer for the context wrong sometimes. Sometimes a person wants a long, elaborate detailed statement, while sometimes they just want it really simple.
Part of the problem is newspapers like this one hyping the leaks to be more sensational than they are. For example, adding context to their quote about al-Husseini, you get:
"Al-Husseini was clear to add that he does not view himself as part of the “peak oil camp,” and does not agree with analysts such as Matthew Simmons. He considers himself optimistic about the future of energy, but pragmatic with regards to what resources are available and what level of production is possible. While he fundamentally contradicts the Aramco company line, al-Husseini is no doomsday theorist."
As for "the kingdom can't keep enough oil flowing to control prices" line? This was 2007-2008; we already *know* they couldn't keep enough oil flowing to control prices back then -- which is why prices weren't controlled. The problem then wasn't an oil flow issue, but an issue of speculation; prices were decoupled from the actual oil supply available. Then they collapsed to way-to-low levels. This volatility has happened with many commodities after the huge surge in commodities speculation in the past 5-10 years.
IT's not "why I think" 1). There's a well documented history of the Shuttle out there which you've apparently never read. The Shuttle had its budget basically slaughtered due to the Vietnam War (plus rate of payloads for it to launch as well; frequent launches are required of reusables for economic viablility). They were forced to make a ton of compromises which significantly increased its operating cost, and even that wasn't enough to get back into budget, so they had to beg the Air Force for money. The Air Force imposed a bunch of new requirements on it which further ruined its economic viability.
The reality is, of course, that there aren't really any significant forces acting on you at all. You're travelling in a straight line when in orbit. It's space that is bent.
Mass production in rocketry is good. It's not a godsend. One of the primary failure modes in rocketry is stage separation. Apply that concept to OTRAG. Also, running many engines in once right near each other isn't as easy as it sounds; failures from one can screw up those around them, vibrations can propagate through the structure, etc. See the Soviet N-1 rocket for an example. More problems abound. The more stages you have, the greater your integration and testing costs as well, which is already an extremely high cost, and would increase linearly with the rocket count. You're *very* vulnerable to pogo with this design. The already abysmal payload fraction keeps getting worse when you take into account things like accounting for different burnout times. Your rocket must start off asymmetrically loaded with fuel (off balance) in order to keep burnout times as close to equal because of when the rocket turns to the horizontal plane, you have to throttle down or off the engines on one side -- either that, or you have it be asymmetrically loaded at burnout.
As for "Rocket a day", mass produciton is no magic wand. It doesn't make your *total* costs lower; it makes your *per-unit* cost lower. Let's say you're making 50 widgets a year for $1 each. You may be able to mass produce the widgets, making 5,000 a year for $0.50 per unit. But you sure as heck better have a market for 5,000 widgets at $0.50 a year, because you're proposing to spend 50 times as much manufacturing widgets. In terms of rocketry, this just won't happen, because the total you have to spend on rocket launches increases so much faster than the price declines will stir up new business.
You also get into the problem that not all rockets are created equal. Payloads to different orbits vary widely. Where they can be launched from varies widely. Some rockets are man-rated. Some can handle in-flight restart. And on and on. A Pegasus is not a substitute for a Delta-IV Heavy. And not only do you have do you have widely varying launch needs, but you have basic human nature: different companies want to make their own stack (and everyone thinks they can do a better job than everyone else), and different companies want their own launch systems for reasons of national pride.
SSTO spaceplanes require either radical improvements in materials or solid improvements in ISP to become a reality. The latter case means either airbreathing (scramjet), metastable/strained bond fuels, or other propulsion methods such as nuclear.
1) Does the Shuttle that was actually produced remotely resemble the Shuttle that was being proposed at the time?
2) One can only make decisions based on the current known body of evidence. Which is that space elevators are not a reasonable thing to pursue in contrast to actively-suspended structures such as launch loops.
Even in theory, "maybe". The strongest single SWNTs measured thusfar are just over 60GPa, a far cry from the predicted 120+ GPa. That may sound like a small difference, but the taper factor means that's a geometric increase in the mass of a space elevator; you really need at least 100GPa for the bulk fiber for it to be even worth consideration. And that's for *bulk fiber*, not for individual tubes, which are always going to be a lot stronger than a bulk fiber.
Plus, space elevators have all sorts of other problems -- inefficient power transport, slow transit times and thus throughput, major undampened oscillations, and on and on. Launch loops are a much better choice in pretty much every regard, and could be built with today's materials and technology. Oh, sure, they're not as glamorous, not as much a staple of sci-fi. But that doesn't change what's the best way to get into space.
Yeah, I was really disappointed by this from Neil. It's extremely poorly done.
1) "Without the Nazis, rockets wouldn't have happened" -- the Nazis merely accelerated something that was already ongoing. All major nations were working on rocketry. There were two primary purposes: sounding rockets, and aircraft. This was, you'll recall, before we knew that jet engines would win out over rockets for airplane propulsion, and all sides were working on rocket-propelled craft. Even if rocket-plane propulsion were to stop, sounding rocket development would have continued to advance to V2-scale. WWII just accelerated things.
2) "A-bombs were too expensive and militarily ineffective" --really? Taking out an entire city and its mass production capability isn't worth the cost to purify some uranium? Perhaps if you divide the number of bombs dropped on Japan by how much we spent on the Manhattan project, maybe, but most of that was a sunk cost. The world was terrified of atomic bombings.
3) "Without A-bombs, rocket development would have ceased." -- ignoring the issues in #1, after WWII, rocketry had already captured the public mind. In fact, even during WWII, Von Braun had already been talking up, and getting military interest in, orbital space bombers that would stay in orbit and drop their (conventional) payloads on enemy targets at a moment's notice (plus taking spy photographs, etc, all without risk of being shot down) during WWII.
4) "All payloads are sized to be like A-bombs" -- not in the least. There's a huge range of payload profiles and lift capabilities of modern rockets. Just because the stacks were originally designed for a specific load doesn't mean that all of their descendants are.
Probably the most disappointing line, however, was:
5) "Rockets are as close to perfect as they're ever going to get." Oh really? Scramjets? Nuclear thermal? Strained-bond chemicals? Cryogenic solids and hybrids? The dramatic materials enhancements we're starting ti get (which has a profound effect on rocket performance)? Advanced heat shields? And on and on. Plus, just ignoring radical changes, look at how much of a difference design approaches have toward launch costs -- compare the Space Shuttle to SpaceX, for example. Rockets are nowhere close to being completely optimized.
There's a lot of legacy that could be criticized with the space industry, esp. the government space industry. Nobody would insist on keeping on reusing as many shuttle components as possible for a next-gen stack if it wasn't all the jobs on the line. Even the "radical", ground-up redesigns, such as SpaceX's Falcon, still uses some legacy parts. So there is a lot of legacy stuff to criticize. But Neal only skimmed over these things:P And he skipped the most important part of such an article: proposing alternatives. So you don't like rockets -- fine. Let's talk alternatives. What do you like -- skyhooks, space elevators, launch loops, ballistic launch, what?
I think about it a different way: the way muons catalyse fusion reactions is by dramatically reducing the covalent bond length (due to their much greater mass, they orbit much closer to the nucleus). Ultra-short laser pulses are known to be able to "dress" electrons with effectively greater mass. I can't help but wonder if there's any prospects for using this to achieve the same thing.
Huh. I've been talking about the concept of using planetary magnetic fields for antimatter production for a decade or so, but it now looks like I'm not the only one:
Bickford's approach is a bit different, though -- instead of including a collision target and trying to accelerate bulk solar wind up to GeV energies, they're looking to merely collect antiparticles already produced by natural collisions, via modified Bussard ram scoop. Not a good enough collection rate for a direct matter/antimatter interstellar mission (only 250 micrograms per year at Saturn, for example), but it'd certainly be a start.
Honestly, I don't see why there should *ever* be a just-plain "coast" phase of a trip. At least keep those engines as hot as you can and run them as a photonic rocket, which yields the maximum-possible Isp (with the downside of very low thrust per unit area). We've already done this -- accidentally! The New Horizons spacecraft was thrust slightly off course because of radiated heat (photons) from the RTG which reflected off of its antenna.
There are a number of proposals for the use of antimatter apart from just pure matter/antimatter annihilation. For example, antimatter-initiated microfission or microfusion is a proposed way to do ICF (what fueled Daedelus) with a far smaller reactor. While the Isp is lower than with puer matter/antimatter annihilation, of course,, it takes far less antimatter. We could potentially produce the required amount here on Earth if we wanted to. Of course, all antimatter designs, but especially direct matter/antimatter annihilation, need to work a lot on trap design.
There are even some pure fission concepts that yield surprisingly good Isp. My favorite is the "dusty fission fragment rocket". Most of the energy in a uranium fission reaction comes in the form of fission fragments. These are large chunks of the uranium nucleus, moving at relativistic velocities. In a traditional fission reactor, they're thermalized, and then the heat is used to heat a working fluid. In a fission fragment reactor, the design is such that the fragments are allowed to escape and can be collimated into a beam, which can then be decelerated to produce energy (or released as a rocket). A dusty fission fragment rocket is a novel approach to work around the heating problems of previous designs; the core is a fine dust of fuel coated in a graphite moderator. The particles readily self-ionize due to decay; with an electrostatic charge on the outside of the reactor, they distribute themselves throughout the core. Because of the fine size of the particles, there's no time for the fragments to be thermalized and they escape (and are then collimated).
Of course, one can always throw away trying to get absurd Isp levels and go for "good" Isp plus simplicity of design, and then focus heavily on staging. A notable design in this regard is that of the nuclear saltwater rocket. The fuel is enriched uranium saltwater, kept in small, neutron-absorbing tubes to prevent criticality. The water is injected into the core where -- a large amount of fuel being in a single place at a single time -- it goes critical, and is directly exhausted out the nozzle.
For the ultimate propulsion (direct matter-antimatter), the big issue comes down to, "how can you produce that much antimatter?" I have a concept I've not had a chance to dig into more of space-based antimatter production which could potentially provide enough for direct matter/antimatter annihilation as well; the concept is to use a natural particle accelerator to accelerate the solar wind (such as near Jupiter, or even more, near Io specifically) up to dozens to hundreds of MeV, and then use an additional magnetic field to pinch it further up to the GeV energies needed for antimatter production, right where your targets/cooling/traps are. Basically, you get your ion stream nearly for free. Heck, there may be enough occasional protons naturally accelerated to the required energies in certain places that you may not need further acceleration; I've not had a chance to dig in detail into the data on Jupiter's radiation belts to say. This all comes with the caveat that I've not had the chance to look up the specific ion energy and density distributions to get a sense of how large and difficult to build such a collector would need to be.
Of course, you can always just accept a lower relativistic velocity and go with a generation ship (or if you want to get really exotic, since there's no way we'd be building an interstellar spacecraft in the near future, one with artificial wombs, frozen embryos, and an automated child-rearing system)
"President Obama seemed to be drawing the lines in the illegal immigration fight. He says he wants to work with Congress to deal with the illegal immigration issue once and for all, to secure our borders and handle the problem. But he says he wants to “stop expelling talented young people” who come from other countries (legally or not), got degrees here, and then take them back home.
My take: It’s a point, but then those people compete against Americans right here for our jobs"
They're Taking Our Jooobbbs!!!!!;)
Why don't we require Economics 101 of our youth? The economy is not a zero-sum game. Money is an IOU, given to you to secure the outputs of your labor, that entitles you to the outputs of someone else's labor (aka, a quality of living). Work creates jobs. People spend their "IOU" on the output of others' labor, creating additional demand for that kind of labor.
Now, one can critique immigrants on a variety of grounds -- for example, that they often send some money home to help their families elsewhere rather than spending it all here. But the overall economic impact of a well-educated and/or hard-working immigrant on our economy is very positive. We don't want people coming to our shores or crossing our borders to leach off of the labor of others. But to work, hard? That *helps* us.
Plus, Obama's main criticism wasn't even what the author portrayed. In addition to trying to retain people who come here on F1 student visas (aka, educated people -- good economic drivers who, by the way, are NOT illegal immigrants), Obama was pushing the DREAM act: supporting the naturalization of *children* of parents who crossed the border illegally with them when they were little. These people grew up here and are generally fully Americanized, have family here, friends, work, etc, but don't have citizenship. I know one family who came to the US legally on a work Visa with their young children, but it eventually expired. The family they had everything up here (a house, a job, friends, etc) and nothing to go back to. They stayed, hoping for the day they'd get the chance to be naturalized. The kids grew up in the US and know nothing of their home country apart from what their parents told them. The kids are as American as anyone else here. Except on paper.
For example, his criticism of Obama's admission that a lot of the old manufacturing jobs are gone and are never coming back, and that we need to lead through tech and innovation:
--- If you think about it, this is the biggest outrage of the speech, because America used to make our living by manufacturing. I liked how this sounds, but on further consideration, it feels like we’re conceding manufacturing prowess to other nations. Since manufacturing fuels jobs, that’s a serious problem. ---
America "used" to make our living by manufacturing because America was one of the few places in the world that had the factories and manufacturing/transportation infrastructure needed to produce things effectively. China was a land of starving peasants scratching away at the land with handmade tools. But third-world countries today have started building up the necessary infrastructure (power, water, roads, communication, etc) and buying the necessary equipment for mass-production (augmenting it with a bountiful, cheap labor supply). Nowadays, the limiting factor on low-tech production is wages. So sure, we could "make a living by manufacturing" those goods, but we'd have to compete with China and India on wages. Anyone here really support that idea? Dropping our wages to China and India's level?
Now, what we can do is exactly what the president said: innovation and technology. And this can even be applied to manufacturing. Wherein we can scale up production rates and decrease production costs using technology as opposed to manual labor sufficiently, we can actually bring back production to the US. But simply trying to force it back to the US with trade policies isn't going to work well. We may not be able to compete in the field of manually screwing the caps on tubes of toothpaste any more, but we can compete in the field of making toothpaste cap-screwing machines. This applies to other things we've been losing as well, such as mining and agriculture.
Now, an interesting thing to think about is the long-term picture. As China and India's wages rise, they become less competitive in the low-tech manufacturing field versus the slower-to-develop third-world nations. They're already starting to feel the force of this, and have been making a push to get into higher tech production. *That* is real competition for the future. And that is what we have to face head-on.
Just to shed some facts on the rhetoric: PolitiFact tracks all of the promises Obama made during the campaign and categorizes them. At present, the results are:
Promise Kept: 134 Compromise: 34 Promise Broken: 34 Stalled: 71 In The Works: 220 Not Yet Rated: 2
"Promise Kept" means he promised it, and has already delivered it largely in-tact (example: Lily Ledbetter Fairl Pay Act). "Compromise" means that he promised it, and managed to get it through congress, but had to compromise or water it down to get it passed (example: a lot of the stuff related to Healthcare). "Promise Broken" means that he promised it, but didn't even try or gave up (example: having a public review period for all bills before signing them). "Stalled" means he's still supporting it, but hasn't been making much progress (difficulties in implementation, congressional obstruction, etc) (example: closing Guantanamo). "In The Works" means that he's pushing it, but it hasn't yet made it to through congress (example: eliminating oil and gas tax loopholes).
Consider that net result as positively or negatively about him as you prefer.
Even weak nuclear reactions generally dwarf chemical reactions. Weak nuclear reactions are usually measured in keV (such as tritium's decay, 18.5keV), while strong nuclear reactions can be hundreds of MeV (uranium fission = ~200MeV). Chemical reactions are generally measured in eV (burning H2 + O2 yields 5.7 eV).
Slashdot Mirror
(as a tanent: using more advanced warhead designs than the previous ones they replace too, so nonproliferation/stockpile-reduction in this case is a very generous casting).
I had a friend who as a translator on one of the old nuclear weapons and delivery systems stockpile reduction treaties with the old USSR before its collapse. She referred to the treaties as a scam because both sides wanted to get rid of their old weapons anyway, and this was just a way for each of them to get some positive PR out of it.
She also had an idea that she presented to... I forget what it was, but I think he was the Soviet equivalent of a colonel. She and some colleagues found it tragic to see these valuable, brilliant pieces of technology, the ballistic delivery systems, just being crushed by bulldozers. So they concocted a (largely tongue-in-cheek) plan to retrofit them into intercontinental pizza delivery systems, and did all of the design work and calculations for fun. You'd have to modify the heat shield and the reentry beta, as well as install proper racks to keep the pizzas in place, and an off-the-shelf spacecraft parachute system. You launch them frozen and they'd come out properly baked. Delivery to anywhere in the world, no matter how remote, in half an hour or so; the cost of the retrofits would make the delivery charge something like $20 per pizza (assuming you ordered a warhead full of them).
Unsurprisingly, the guy looked at them like they were crazy ;)
All the commercial reactors in the US are light water (normal H20) and countries that use heavy water (Canada) may not be interested in stockpiling tritium.
I'm sure Canada is up for the challenge; they have a real can-du attitude. ;)
It's the same as the situation with indium. Indium is found in conjunction with most copper, lead, tin, etc ores. However, there's historically been such a low demand for indium that just a couple mines had recovery circuits. And right as indium demand started to rise, one of the mines went out of business as its primary ore was no longer economical. So indium prices went through the roof in 2004/2005. Of course, that triggers more mines to install recovery circuits, but it takes time to get a new recovery circuit online.
"Just get it from the moon" -- as though it doesn't cost $5-15k per kilogram just to get a *vehicle* into *low earth orbit*. Let alone the surface of the moon. Let alone a return trip to the moon. Let alone a return trip to the moon and hauling enough manpower and equipment to mine the moon. For something that's found in parts-per-billion quantities, mixed in with parts-per-million quantities of something that's essentially chemically identical (He-4).
It's way, way easier to produce He3 here on earth; it's a decay product of tritium, which is bred from lithium which is exposed to a neutron flux (aka, a lithium blanket in a nuclear reactor). Which is why it was a byproduct of our thermonuclear weapon stockpile; as they sit, their tritium slowly decays.
That's incorrect.
Helium-3 is a *byproduct* of the *existence* of hydrogen bombs. More specifically, byproduct of the existence of tritium. Tritium decays into helium-3. Helium-3 was unwanted, while tritium was wanted; there were actually some projects to attempt to convert the helium-3 back into tritium.
This shortage has absolutely nothing to do with how easy or hard helium-3 is to produce or acquire, nor is it a testament to how "free market planning" works so much better than central planning. Quite the opposite, this is a well known phenomenon of free markets: products which are of lower value and which are produced in a limited number of places as a byproduct of producing a more valuable goods can be extremely vulnerable to price swings.
I must have missed when they probed those 1,235 planets for evidence of civilization and declared that they were able to rule it out.
I can't help but feel that this proposal was designed by the good folks at Aperture Science ;) I mean, seriously -- you really feel the need to teach satellites to read english just to avoid collisions? Was I not the only one who immediately pictured:
-----
x Defense Logistics Agency solicits bids for development of fuel icing inhibitor (FSII)
x Black Mesa FSII proposal:
x x Costly: Black Mesa personnel overpaid given limited skillset/ambition.
x x Design inhibits ice, nothing more
x Aperture Proposal:
x x Less expensive
x x Bonus to DLA: Aperture FSII inhibits ice but is also :
x x x A fully functional Disk Operating System
x x x Arguably alive
-----
Also, this quote, from elsewhere:
-----
"When someone says 'I want a programming language in which I need only say what I wish done,' give them a lollipop."
-----
What makes you think that we don't just give the most statistically likely answer because of many similar sentences (or more accurately, concepts) in our mental "database"? What makes you so sure that what Watson is doing is really so fundamentally different from what we do? Our brains don't work via fairy dust and rainbows; it's not magic.
Your "cow is to grass" example is actually a relatively simple challenge in AI. Lots of things really complicate it. Understanding human motivations, for example, requires a lot more than just a basic dictionary relationship of what powers what:
"Johnny wanted some money, so he bought a gun, walked into a store, and asked the clerk for money. The clerk gave him money. Why did the clerk give him money?"
Or parsing multiple contradictory concepts, which require that you be able to accept contradictory facts as true in different contexts:
* Dracula is a vampire.
* There is no such thing as a vampire.
* Dracula resides in Transylvania.
* Dracula does not reside in Transylvania.
* Dracula is immortal.
* Nothing is immortal.
Etc. All true statements in their own context. And there can be an arbitrary number of contexts. Think, for example, of the question, "What happens to you when you die?" All contexts would generally accept a physical description of your body's decay, but different religious contexts would have all sorts of statements which are "true" within their context but "false" in many others.
Watson's answer was completely correct -- it just didn't elaborate enough. There are various degrees of specificity one could use:
* Leg
* Missing a leg
* Missing a left leg
* A prosthesis in place of a missing left leg
* A wooden prosthesis in place of a missing left leg
And so on. All of these are correct; it's just varying degrees of specificity. And I have no doubt that Watson had the information available and processed to provide all of those answers, had it simply been instructed to be a bit less laconic with its answers. The same thing will apply to other uses for Watson. For example, they mentioned that they want to use it for medical applications. Well, in response to, "What is the source of this woman's infertility?", the answers, with varying degrees of specificity, could be:
* Uterus
* Missing a uterus
* Mullerian agenesis
* Missing a uterus due to mullerian agenesis
* WNT4
* WNT4 gene
* A defective WNT4
* A defective WNT4 gene
* Missing a uterus due to WNT4
* Missing a uterus due to WNT4 gene
* Missing a uterus due to a defective WNT4
* Missing a uterus due to a defective WNT4 gene
* Mullerian agenesis due to WNT4
* Mullerian agenesis due to WNT4 gene
* Mullerian agenesis due to a defective WNT4
* Mullerian agenesis due to a defective WNT4 gene
* Missing a uterus due to mullerian agenesis due to WNT4
* Missing a uterus due to mullerian agenesis due to WNT4 gene
* Missing a uterus due to mullerian agenesis due to a defective WNT4
* Missing a uterus due to mullerian agenesis due to a defective WNT4 gene
* All of the above with details on why the WNT4 gene is defective
And so on. What's the right answer? It depends on the context. Are you filling out an insurance form or working on a peer-reviewed paper? And even humans judge the right answer for the context wrong sometimes. Sometimes a person wants a long, elaborate detailed statement, while sometimes they just want it really simple.
You just failed Parrots 101, too. They're hardly mindless mimics.
Part of the problem is newspapers like this one hyping the leaks to be more sensational than they are. For example, adding context to their quote about al-Husseini, you get:
"Al-Husseini was clear to add that he does not view himself as part of the “peak oil camp,” and does not agree with analysts such as Matthew Simmons. He considers himself optimistic about the future of energy, but pragmatic with regards to what resources are available and what level of production is possible. While he fundamentally contradicts the Aramco company line, al-Husseini is no doomsday theorist."
As for "the kingdom can't keep enough oil flowing to control prices" line? This was 2007-2008; we already *know* they couldn't keep enough oil flowing to control prices back then -- which is why prices weren't controlled. The problem then wasn't an oil flow issue, but an issue of speculation; prices were decoupled from the actual oil supply available. Then they collapsed to way-to-low levels. This volatility has happened with many commodities after the huge surge in commodities speculation in the past 5-10 years.
IT's not "why I think" 1). There's a well documented history of the Shuttle out there which you've apparently never read. The Shuttle had its budget basically slaughtered due to the Vietnam War (plus rate of payloads for it to launch as well; frequent launches are required of reusables for economic viablility). They were forced to make a ton of compromises which significantly increased its operating cost, and even that wasn't enough to get back into budget, so they had to beg the Air Force for money. The Air Force imposed a bunch of new requirements on it which further ruined its economic viability.
Explain how exactly that applies here.
Come now, do you really expect me to do coordinate substitution in my head while strapped to a centrifuge?
The reality is, of course, that there aren't really any significant forces acting on you at all. You're travelling in a straight line when in orbit. It's space that is bent.
Mass production in rocketry is good. It's not a godsend. One of the primary failure modes in rocketry is stage separation. Apply that concept to OTRAG. Also, running many engines in once right near each other isn't as easy as it sounds; failures from one can screw up those around them, vibrations can propagate through the structure, etc. See the Soviet N-1 rocket for an example. More problems abound. The more stages you have, the greater your integration and testing costs as well, which is already an extremely high cost, and would increase linearly with the rocket count. You're *very* vulnerable to pogo with this design. The already abysmal payload fraction keeps getting worse when you take into account things like accounting for different burnout times. Your rocket must start off asymmetrically loaded with fuel (off balance) in order to keep burnout times as close to equal because of when the rocket turns to the horizontal plane, you have to throttle down or off the engines on one side -- either that, or you have it be asymmetrically loaded at burnout.
As for "Rocket a day", mass produciton is no magic wand. It doesn't make your *total* costs lower; it makes your *per-unit* cost lower. Let's say you're making 50 widgets a year for $1 each. You may be able to mass produce the widgets, making 5,000 a year for $0.50 per unit. But you sure as heck better have a market for 5,000 widgets at $0.50 a year, because you're proposing to spend 50 times as much manufacturing widgets. In terms of rocketry, this just won't happen, because the total you have to spend on rocket launches increases so much faster than the price declines will stir up new business.
You also get into the problem that not all rockets are created equal. Payloads to different orbits vary widely. Where they can be launched from varies widely. Some rockets are man-rated. Some can handle in-flight restart. And on and on. A Pegasus is not a substitute for a Delta-IV Heavy. And not only do you have do you have widely varying launch needs, but you have basic human nature: different companies want to make their own stack (and everyone thinks they can do a better job than everyone else), and different companies want their own launch systems for reasons of national pride.
Both "Rocket-A-Day" and OTRAG have serious flaws.
SSTO spaceplanes require either radical improvements in materials or solid improvements in ISP to become a reality. The latter case means either airbreathing (scramjet), metastable/strained bond fuels, or other propulsion methods such as nuclear.
1) Does the Shuttle that was actually produced remotely resemble the Shuttle that was being proposed at the time?
2) One can only make decisions based on the current known body of evidence. Which is that space elevators are not a reasonable thing to pursue in contrast to actively-suspended structures such as launch loops.
Even in theory, "maybe". The strongest single SWNTs measured thusfar are just over 60GPa, a far cry from the predicted 120+ GPa. That may sound like a small difference, but the taper factor means that's a geometric increase in the mass of a space elevator; you really need at least 100GPa for the bulk fiber for it to be even worth consideration. And that's for *bulk fiber*, not for individual tubes, which are always going to be a lot stronger than a bulk fiber.
Plus, space elevators have all sorts of other problems -- inefficient power transport, slow transit times and thus throughput, major undampened oscillations, and on and on. Launch loops are a much better choice in pretty much every regard, and could be built with today's materials and technology. Oh, sure, they're not as glamorous, not as much a staple of sci-fi. But that doesn't change what's the best way to get into space.
Yeah, I was really disappointed by this from Neil. It's extremely poorly done.
1) "Without the Nazis, rockets wouldn't have happened" -- the Nazis merely accelerated something that was already ongoing. All major nations were working on rocketry. There were two primary purposes: sounding rockets, and aircraft. This was, you'll recall, before we knew that jet engines would win out over rockets for airplane propulsion, and all sides were working on rocket-propelled craft. Even if rocket-plane propulsion were to stop, sounding rocket development would have continued to advance to V2-scale. WWII just accelerated things.
2) "A-bombs were too expensive and militarily ineffective" --really? Taking out an entire city and its mass production capability isn't worth the cost to purify some uranium? Perhaps if you divide the number of bombs dropped on Japan by how much we spent on the Manhattan project, maybe, but most of that was a sunk cost. The world was terrified of atomic bombings.
3) "Without A-bombs, rocket development would have ceased." -- ignoring the issues in #1, after WWII, rocketry had already captured the public mind. In fact, even during WWII, Von Braun had already been talking up, and getting military interest in, orbital space bombers that would stay in orbit and drop their (conventional) payloads on enemy targets at a moment's notice (plus taking spy photographs, etc, all without risk of being shot down) during WWII.
4) "All payloads are sized to be like A-bombs" -- not in the least. There's a huge range of payload profiles and lift capabilities of modern rockets. Just because the stacks were originally designed for a specific load doesn't mean that all of their descendants are.
Probably the most disappointing line, however, was:
5) "Rockets are as close to perfect as they're ever going to get." Oh really? Scramjets? Nuclear thermal? Strained-bond chemicals? Cryogenic solids and hybrids? The dramatic materials enhancements we're starting ti get (which has a profound effect on rocket performance)? Advanced heat shields? And on and on. Plus, just ignoring radical changes, look at how much of a difference design approaches have toward launch costs -- compare the Space Shuttle to SpaceX, for example. Rockets are nowhere close to being completely optimized.
There's a lot of legacy that could be criticized with the space industry, esp. the government space industry. Nobody would insist on keeping on reusing as many shuttle components as possible for a next-gen stack if it wasn't all the jobs on the line. Even the "radical", ground-up redesigns, such as SpaceX's Falcon, still uses some legacy parts. So there is a lot of legacy stuff to criticize. But Neal only skimmed over these things :P And he skipped the most important part of such an article: proposing alternatives. So you don't like rockets -- fine. Let's talk alternatives. What do you like -- skyhooks, space elevators, launch loops, ballistic launch, what?
I think about it a different way: the way muons catalyse fusion reactions is by dramatically reducing the covalent bond length (due to their much greater mass, they orbit much closer to the nucleus). Ultra-short laser pulses are known to be able to "dress" electrons with effectively greater mass. I can't help but wonder if there's any prospects for using this to achieve the same thing.
Huh. I've been talking about the concept of using planetary magnetic fields for antimatter production for a decade or so, but it now looks like I'm not the only one:
Extraction of Antiparticles Concentrated In Planetary Magnetic Fields
Bickford's approach is a bit different, though -- instead of including a collision target and trying to accelerate bulk solar wind up to GeV energies, they're looking to merely collect antiparticles already produced by natural collisions, via modified Bussard ram scoop. Not a good enough collection rate for a direct matter/antimatter interstellar mission (only 250 micrograms per year at Saturn, for example), but it'd certainly be a start.
There's a lot more types of engines than that. :P
Honestly, I don't see why there should *ever* be a just-plain "coast" phase of a trip. At least keep those engines as hot as you can and run them as a photonic rocket, which yields the maximum-possible Isp (with the downside of very low thrust per unit area). We've already done this -- accidentally! The New Horizons spacecraft was thrust slightly off course because of radiated heat (photons) from the RTG which reflected off of its antenna.
There are a number of proposals for the use of antimatter apart from just pure matter/antimatter annihilation. For example, antimatter-initiated microfission or microfusion is a proposed way to do ICF (what fueled Daedelus) with a far smaller reactor. While the Isp is lower than with puer matter/antimatter annihilation, of course,, it takes far less antimatter. We could potentially produce the required amount here on Earth if we wanted to. Of course, all antimatter designs, but especially direct matter/antimatter annihilation, need to work a lot on trap design.
There are even some pure fission concepts that yield surprisingly good Isp. My favorite is the "dusty fission fragment rocket". Most of the energy in a uranium fission reaction comes in the form of fission fragments. These are large chunks of the uranium nucleus, moving at relativistic velocities. In a traditional fission reactor, they're thermalized, and then the heat is used to heat a working fluid. In a fission fragment reactor, the design is such that the fragments are allowed to escape and can be collimated into a beam, which can then be decelerated to produce energy (or released as a rocket). A dusty fission fragment rocket is a novel approach to work around the heating problems of previous designs; the core is a fine dust of fuel coated in a graphite moderator. The particles readily self-ionize due to decay; with an electrostatic charge on the outside of the reactor, they distribute themselves throughout the core. Because of the fine size of the particles, there's no time for the fragments to be thermalized and they escape (and are then collimated).
Of course, one can always throw away trying to get absurd Isp levels and go for "good" Isp plus simplicity of design, and then focus heavily on staging. A notable design in this regard is that of the nuclear saltwater rocket. The fuel is enriched uranium saltwater, kept in small, neutron-absorbing tubes to prevent criticality. The water is injected into the core where -- a large amount of fuel being in a single place at a single time -- it goes critical, and is directly exhausted out the nozzle.
For the ultimate propulsion (direct matter-antimatter), the big issue comes down to, "how can you produce that much antimatter?" I have a concept I've not had a chance to dig into more of space-based antimatter production which could potentially provide enough for direct matter/antimatter annihilation as well; the concept is to use a natural particle accelerator to accelerate the solar wind (such as near Jupiter, or even more, near Io specifically) up to dozens to hundreds of MeV, and then use an additional magnetic field to pinch it further up to the GeV energies needed for antimatter production, right where your targets/cooling/traps are. Basically, you get your ion stream nearly for free. Heck, there may be enough occasional protons naturally accelerated to the required energies in certain places that you may not need further acceleration; I've not had a chance to dig in detail into the data on Jupiter's radiation belts to say. This all comes with the caveat that I've not had the chance to look up the specific ion energy and density distributions to get a sense of how large and difficult to build such a collector would need to be.
Of course, you can always just accept a lower relativistic velocity and go with a generation ship (or if you want to get really exotic, since there's no way we'd be building an interstellar spacecraft in the near future, one with artificial wombs, frozen embryos, and an automated child-rearing system)
Oh, and who could forget:
"President Obama seemed to be drawing the lines in the illegal immigration fight. He says he wants to work with Congress to deal with the illegal immigration issue once and for all, to secure our borders and handle the problem. But he says he wants to “stop expelling talented young people” who come from other countries (legally or not), got degrees here, and then take them back home.
My take: It’s a point, but then those people compete against Americans right here for our jobs"
They're Taking Our Jooobbbs!!!!! ;)
Why don't we require Economics 101 of our youth? The economy is not a zero-sum game. Money is an IOU, given to you to secure the outputs of your labor, that entitles you to the outputs of someone else's labor (aka, a quality of living). Work creates jobs. People spend their "IOU" on the output of others' labor, creating additional demand for that kind of labor.
Now, one can critique immigrants on a variety of grounds -- for example, that they often send some money home to help their families elsewhere rather than spending it all here. But the overall economic impact of a well-educated and/or hard-working immigrant on our economy is very positive. We don't want people coming to our shores or crossing our borders to leach off of the labor of others. But to work, hard? That *helps* us.
Plus, Obama's main criticism wasn't even what the author portrayed. In addition to trying to retain people who come here on F1 student visas (aka, educated people -- good economic drivers who, by the way, are NOT illegal immigrants), Obama was pushing the DREAM act: supporting the naturalization of *children* of parents who crossed the border illegally with them when they were little. These people grew up here and are generally fully Americanized, have family here, friends, work, etc, but don't have citizenship. I know one family who came to the US legally on a work Visa with their young children, but it eventually expired. The family they had everything up here (a house, a job, friends, etc) and nothing to go back to. They stayed, hoping for the day they'd get the chance to be naturalized. The kids grew up in the US and know nothing of their home country apart from what their parents told them. The kids are as American as anyone else here. Except on paper.
Agreed completely.
For example, his criticism of Obama's admission that a lot of the old manufacturing jobs are gone and are never coming back, and that we need to lead through tech and innovation:
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If you think about it, this is the biggest outrage of the speech, because America used to make our living by manufacturing. I liked how this sounds, but on further consideration, it feels like we’re conceding manufacturing prowess to other nations. Since manufacturing fuels jobs, that’s a serious problem.
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America "used" to make our living by manufacturing because America was one of the few places in the world that had the factories and manufacturing/transportation infrastructure needed to produce things effectively. China was a land of starving peasants scratching away at the land with handmade tools. But third-world countries today have started building up the necessary infrastructure (power, water, roads, communication, etc) and buying the necessary equipment for mass-production (augmenting it with a bountiful, cheap labor supply). Nowadays, the limiting factor on low-tech production is wages. So sure, we could "make a living by manufacturing" those goods, but we'd have to compete with China and India on wages. Anyone here really support that idea? Dropping our wages to China and India's level?
Now, what we can do is exactly what the president said: innovation and technology. And this can even be applied to manufacturing. Wherein we can scale up production rates and decrease production costs using technology as opposed to manual labor sufficiently, we can actually bring back production to the US. But simply trying to force it back to the US with trade policies isn't going to work well. We may not be able to compete in the field of manually screwing the caps on tubes of toothpaste any more, but we can compete in the field of making toothpaste cap-screwing machines. This applies to other things we've been losing as well, such as mining and agriculture.
Now, an interesting thing to think about is the long-term picture. As China and India's wages rise, they become less competitive in the low-tech manufacturing field versus the slower-to-develop third-world nations. They're already starting to feel the force of this, and have been making a push to get into higher tech production. *That* is real competition for the future. And that is what we have to face head-on.
Just to shed some facts on the rhetoric: PolitiFact tracks all of the promises Obama made during the campaign and categorizes them. At present, the results are:
http://www.politifact.com/truth-o-meter/promises/obameter/
Promise Kept: 134
Compromise: 34
Promise Broken: 34
Stalled: 71
In The Works: 220
Not Yet Rated: 2
"Promise Kept" means he promised it, and has already delivered it largely in-tact (example: Lily Ledbetter Fairl Pay Act). "Compromise" means that he promised it, and managed to get it through congress, but had to compromise or water it down to get it passed (example: a lot of the stuff related to Healthcare). "Promise Broken" means that he promised it, but didn't even try or gave up (example: having a public review period for all bills before signing them). "Stalled" means he's still supporting it, but hasn't been making much progress (difficulties in implementation, congressional obstruction, etc) (example: closing Guantanamo). "In The Works" means that he's pushing it, but it hasn't yet made it to through congress (example: eliminating oil and gas tax loopholes).
Consider that net result as positively or negatively about him as you prefer.
Even weak nuclear reactions generally dwarf chemical reactions. Weak nuclear reactions are usually measured in keV (such as tritium's decay, 18.5keV), while strong nuclear reactions can be hundreds of MeV (uranium fission = ~200MeV). Chemical reactions are generally measured in eV (burning H2 + O2 yields 5.7 eV).