If you had read TFA, you would have seen that for this speed run they are skipping to regenerator: it's large, heavy, and bulky, and for a sprint run of a few minutes they don't need it.
There are all kinds of external combustion engines out there. External combustion means that you have a heat source (a boiler, burner, etc.) that heats up some working fluid (often steam), and the working fluid performs useful work as it expands and cools. Every coal- and oil-fired electrical generation plant is a kind of an external combustor. Nuclear stretches the semantics a bit, because the heat doesn't come from combustion per se. Some natural gas plants are, too, though the preferred architecture these days is combined cycle. Stirling engines are another external combustor. The "external" in this case means that the combustion is happening outside of the mechanical workings.
External combustion has the significant advantage that it doesn't really matter where the heat comes from. Boilers are tuned to work with a specific fuel, and can be further tuned to work on a specific grade of a specific fuel. But beyond that, all the rest of the infrastructure can be input-agnostic: all you need is heat. Contrast this to the internal combustion engine, which is very heavily tuned to its fuel source. Diesels tend to be a bit more forgiving, and modern engine controls allow for a wider efficient operating range, but you would destroy a typical gasoline ICE if you accidentally gave it diesel.
That doesn't, by itself, automatically mean there must be higher hills to climb.
But in the two areas he focuses his conclusion on - rocketry and energy - there are demonstrably higher hills to climb. There are other architectures and paradigms that, on paper or in experimentation, guarantee better efficiency, lowered risk, lower cost, etc. If we, collectively, only had the fortitude to start climbing again.
I think you are missing a key part of his conclusion:
But none of the bright young up-and-coming economies seem to be interested in anything besides aping what the United States and the USSR did years ago. We may, in other words, need to look beyond strictly U.S.-centric explanations for such failures of imagination and initiative.
He has laid out a good case explaining why the U.S. isn't dumping its investment to start over. What he is wondering about is why no one else is trying it, either. Think of China: they have resources and means to develop something wholly new. But all they are doing is building solid- and liquid-fueled rockets to fling soyuz-like capsules into orbit. Why?
Could we please agree that 100 Gbps, especially in this context, is not a "barrier"? At best, it is a mildly interesting milestone in the march towards completely saturating the internet with crap. But it is not a barrier in the sense that there was some physical limitation that held us up on our way past it. True, it happens to match the rated throughput of a particular class of network routing equipment, but so what? The sound barrier was an actual barrier in airspeed, one which many objects and phenomena cannot overcome, and one that took extra effort to get humans past. A brick wall is a barrier to your forward progress that requires extra effort to push through (if you're into that kind of thing). But 100 Gbps is no more a barrier than 99 Gbps was or 101 Gbps will be. Round numbers are not barriers - they're just human conventions.
That would only work as a strategy if they could sell these hypermilers in numbers comparable to gas guzzlers. I find it unlikely in the near future. And as with so many such vehicles, I'm guessing that the actual mileage rating will get tweaked downward when the actual ratings agencies get their hands on it.
And even if this kind of car is part of their strategy to bring their CAFE numbers up to snuff, so what? The fleet mpg average goes up, fuel consumption goes down, what's the problem with that? CAFE isn't exactly the way I would go about enforcing fuel efficiency*, but it is progress.
* mpg is a misleading measure of fuel consumption anyway, L / km is better, and kW / km is better still when talking about hybrid or all-electric powertrains
Another contributor to the increasing ratio of college-educated salaries to those without has been the decline of manufacturing. There was a time over the last 2-3 generations when someone without a college degree could still get a decent job in manufacturing with benefits and good pay. There was value in skilled trades. The specific example I am thinking of is the automotive industry, where an assembly-line worker could make $20-30 an hour with benefits, and a good machinist could earn as much as a white-collar. Whether that was prudent or sustainable economically or socially is another matter, but it was the case.
With the decline in manufacturing jobs and labor unions, brought on by increased productivity, increased global competition, and the economic downturn generally, it is harder for the uneducated to find jobs that don't have shit conditions for a shit wage.
More recently, the economic downturn has hit those without college educations disproportionately high (manufacturing, construction, etc.), which would tend to depress their median income level, leading to a greater skew that might not otherwise be there.
One would think that, this being Blu-Ray with prodigious storage abilities, you would be able to choose the version from some on-screen menu. Include or remove scenes (do we want to see Han and Jabba chit-chat in Episode IV?), swap in different version of the same scene (han shot first! death star explosion with or without shockwave), even change the soundtrack (super-echo before swinging across the abyss or no?) - it's all pretty straightforward from a technical standpoint.
Whether the Emperor...uhhh...George Lucas will permit it is another question.
It's not only NASA vs. SciFi Movies. That problem can be seen in a lot of genres.
I know! I'm feeling soooo deceived by the movie's I've seen lately. I mean, I was at the hospital the other day, and the nurse was not wearing a form-fitting white uniform with a plunging neckline. She didn't come on to me or tell me how naughty she'd been. She didn't even have enormous breasts! B-cup, tops! All she did was poke me with needles and bring me terrible food!
Yes, but let's say you are somewhere in the middle of North America: the pole would have to move hundreds of kilometers before you would get that 1-degree shift.
I submit that: unless you are using surveying equipment or a theodolite, your measurement error, hasty reckoning, even your metal belt buckle, will probably have more effect than the shift in the location of magnetic north.
It's been bandied about for a long time. The problem is the energy involved (or, more directly, the velocity). In order for this concept to work, you'd need to accelerate the payload to an orbital velocity (several kilometers per second), at ground level, before it even left the surface. That's roughly Mach 10, something we've never even come close to achieving at anywhere close to sea level. You'd also need to add in a lot of extra velocity, because you'd lose a lot to air friction. Building a hypersonic payload capsule is no easy task.
Then there's the practical concerns of how you'd built the thing. The size of the thing depends greatly on how much acceleration your payload can tolerate. If it were a linear accelerator, it would need to be tens of kilometers long (the last few kilometers would be passed by in about a second!). A circular one would probably need to be at least several kilometers in diameter (so that centripetal acceleration doesn't crush you when your tangential velocity is kilometers per second, increase radius). It'd all need to be superconductive, too. The closest we've ever built to something like that is the LHC, which can impart on a cluster of protons, in a vacuum, at liquid helium temperatures, roughly the equivalent energy of a fast-pitched baseball. The actual acceleration is done based on electrical charge, which makes it pretty easy - the big magnets just steer the beam in a circle. A payload is electrically neutral, so the acceleration would be done magnetically (like this new aircraft catapult), which is frankly more difficult to do.
So, in short,you probably could do it, but it involves enormous technical challenges, a generation or two's worth of R&D, and probably tens if not hundreds of billions of dollars in capital costs. Even then, your payload capacity to LEO may be very small, and it may not be physiologically safe for humans.
What would probably be a better use of technology would be a 747-sized catapult that could gently accelerate (or assist in accelerating) large aircraft down an airport runway up to speeds of, say, 300 km/h.
The majority of the molten salt is at ground level: the top of the tower is just where it is heated. If you look at the images accompanying the article, you'll see that in their schematic. Also, you'll see an image showing the two heat storage tanks down on the ground: they are actually a bit below grade, and there is a bowl-like structure surrounding each in case of a release.
Probably it's a typo, and they meant to write "name" with reference to Calligula, but what the hell is a "neme". Is that some new-fangled internet term for a name-meme? And what the hell is that supposed to mean?
My reading of this is not so much that there is something inherently wrong with the PDF format itself, but rather with how it is used. If you are a government agency, producing documents for public consumption, you better know how the hell to produce a PDF with searchable, readable text, and not sequester it to image-only. If you can't get that single concept into your head, it won't matter what fucking format you use.you would think bureaucrats, with their stickler for regulation and procedure, would be able to understand that not every PDF is created equal: some are produced much better than others.
The authors of the report say as much in their summary:
while accessibility of the Portable Document Format is improving, like most tools, it cannot compensate for poor design. Content authors need to design accessibility into their documents from the outset.
And while both the article summary and the report itself stress the need to provide alternate formats alongside (or in place of) PDF, the full report is scant on details or comparative tests of other formats. HTML and RTF seem decent options, as they permit some text formatting options (but are not wedded to them) and are platform-independent. But when you start adding graphics to the mix (as sometimes must happen) their portability tanks. They also cannot prevent the same problem that plagues PDFs: when some dipshit just scans a document and spits out an image-only file.
(PS - would it have killed the submitter and editors to link to the main report page, rather than only to a second-hand link from ITNews Australia?)
The results look an almost identical to the kind of data I get from the NextEngine 3D laser scanner. To create a 3D surface, the device sweeps a laser across the object in front of it. The laser sweeps a vertical line, and shines on the (arbitary) surface of the object in front of it. Stereo cameras capture the shape of the laser line from different angles, and software is able to extract the 3D surface from there. An accompanying visible light image from one camera or the other is used to apply a "skin" to what is otherwise a wireframe. By using a laser and taking its time, rather than broadcasting an infrared grid of fiducial dots, the results are very good: sub-millimeter accuracy is easy, though for handheld objects, not people in a room. Similar technology can be used for very large scale models, such as the I-35W bridgecollapse in Minneapolis.
Actually, what confuses me is the apparent contradiction in the summary: how is it that the requirements mandate a solid-rocket design, yet NASA is also considering all-liquid designs? I wouldn't put it past NASA to do contradictory things, but I would hope the summary-writer and editors could explain things better.
I've got it! A solid liquid design! What will those guys think of next!
What shall we consider the when we talk about a satellite being "largest?" As we all know, physical size doesn't matter all that much in space. Weight (or rather, mass) in orbit is probably a greater achievement. The ISS probably takes the cake by both measures, though definitions and semantics make for a tricky comparison.
The Shuttle, empty and floating in orbit, has a mass of roughly 2000 metric tons. Perhaps, for semantics, we won't consider that a satellite, either.
For more conventional satellites (i.e., hunks of unmanned electronics that do some useful purpose for years on end), I think the heaviest ever was the Compton Gamma Ray Observatory at 17 metric tons, which was sent aloft using the Shuttle, because it was too heavy for any rocket at the time.
Cassini-Huygens had a launch weight of nearly 6 metric tons, and also used a Titan 4 Heavy. Considering they launched it all the way to fucking Saturn, that also seems a bigger achievement than this latest spy satellite.
Just wait until we have a solar sail testbed out there with a 1-km span, but with a mass of just 10 kg.
Slashdot Mirror
Does mean we can get the annoying Verizon wireless guy to hold this way up high in the middle of a thunderstorm?
well, how else are the remote administrators supposed to access the routing centers and turn the internets back on?
If you had read TFA, you would have seen that for this speed run they are skipping to regenerator: it's large, heavy, and bulky, and for a sprint run of a few minutes they don't need it.
There are all kinds of external combustion engines out there. External combustion means that you have a heat source (a boiler, burner, etc.) that heats up some working fluid (often steam), and the working fluid performs useful work as it expands and cools. Every coal- and oil-fired electrical generation plant is a kind of an external combustor. Nuclear stretches the semantics a bit, because the heat doesn't come from combustion per se. Some natural gas plants are, too, though the preferred architecture these days is combined cycle. Stirling engines are another external combustor. The "external" in this case means that the combustion is happening outside of the mechanical workings.
External combustion has the significant advantage that it doesn't really matter where the heat comes from. Boilers are tuned to work with a specific fuel, and can be further tuned to work on a specific grade of a specific fuel. But beyond that, all the rest of the infrastructure can be input-agnostic: all you need is heat. Contrast this to the internal combustion engine, which is very heavily tuned to its fuel source. Diesels tend to be a bit more forgiving, and modern engine controls allow for a wider efficient operating range, but you would destroy a typical gasoline ICE if you accidentally gave it diesel.
That isn't very reassuring.
But in the two areas he focuses his conclusion on - rocketry and energy - there are demonstrably higher hills to climb. There are other architectures and paradigms that, on paper or in experimentation, guarantee better efficiency, lowered risk, lower cost, etc. If we, collectively, only had the fortitude to start climbing again.
He has laid out a good case explaining why the U.S. isn't dumping its investment to start over. What he is wondering about is why no one else is trying it, either. Think of China: they have resources and means to develop something wholly new. But all they are doing is building solid- and liquid-fueled rockets to fling soyuz-like capsules into orbit. Why?
Well, if Chinese state media reports it, it must be true!
Given the difficulty of getting rockets to work, I'd take just about anything to tip the odds in my favor.
Could we please agree that 100 Gbps, especially in this context, is not a "barrier"? At best, it is a mildly interesting milestone in the march towards completely saturating the internet with crap. But it is not a barrier in the sense that there was some physical limitation that held us up on our way past it. True, it happens to match the rated throughput of a particular class of network routing equipment, but so what? The sound barrier was an actual barrier in airspeed, one which many objects and phenomena cannot overcome, and one that took extra effort to get humans past. A brick wall is a barrier to your forward progress that requires extra effort to push through (if you're into that kind of thing). But 100 Gbps is no more a barrier than 99 Gbps was or 101 Gbps will be. Round numbers are not barriers - they're just human conventions.
That would only work as a strategy if they could sell these hypermilers in numbers comparable to gas guzzlers. I find it unlikely in the near future. And as with so many such vehicles, I'm guessing that the actual mileage rating will get tweaked downward when the actual ratings agencies get their hands on it.
And even if this kind of car is part of their strategy to bring their CAFE numbers up to snuff, so what? The fleet mpg average goes up, fuel consumption goes down, what's the problem with that? CAFE isn't exactly the way I would go about enforcing fuel efficiency*, but it is progress.
* mpg is a misleading measure of fuel consumption anyway, L / km is better, and kW / km is better still when talking about hybrid or all-electric powertrains
Another contributor to the increasing ratio of college-educated salaries to those without has been the decline of manufacturing. There was a time over the last 2-3 generations when someone without a college degree could still get a decent job in manufacturing with benefits and good pay. There was value in skilled trades. The specific example I am thinking of is the automotive industry, where an assembly-line worker could make $20-30 an hour with benefits, and a good machinist could earn as much as a white-collar. Whether that was prudent or sustainable economically or socially is another matter, but it was the case.
With the decline in manufacturing jobs and labor unions, brought on by increased productivity, increased global competition, and the economic downturn generally, it is harder for the uneducated to find jobs that don't have shit conditions for a shit wage.
More recently, the economic downturn has hit those without college educations disproportionately high (manufacturing, construction, etc.), which would tend to depress their median income level, leading to a greater skew that might not otherwise be there.
Yes, I think we could even at this point pen a new meme around it, much like the steps in an Apple Product Cycle
Oceania has always been at war with Eastasia. [ref]
One would think that, this being Blu-Ray with prodigious storage abilities, you would be able to choose the version from some on-screen menu. Include or remove scenes (do we want to see Han and Jabba chit-chat in Episode IV?), swap in different version of the same scene (han shot first! death star explosion with or without shockwave), even change the soundtrack (super-echo before swinging across the abyss or no?) - it's all pretty straightforward from a technical standpoint.
Whether the Emperor...uhhh...George Lucas will permit it is another question.
I know! I'm feeling soooo deceived by the movie's I've seen lately. I mean, I was at the hospital the other day, and the nurse was not wearing a form-fitting white uniform with a plunging neckline. She didn't come on to me or tell me how naughty she'd been. She didn't even have enormous breasts! B-cup, tops! All she did was poke me with needles and bring me terrible food!
Yes, but let's say you are somewhere in the middle of North America: the pole would have to move hundreds of kilometers before you would get that 1-degree shift.
I submit that: unless you are using surveying equipment or a theodolite, your measurement error, hasty reckoning, even your metal belt buckle, will probably have more effect than the shift in the location of magnetic north.
It's been bandied about for a long time. The problem is the energy involved (or, more directly, the velocity). In order for this concept to work, you'd need to accelerate the payload to an orbital velocity (several kilometers per second), at ground level, before it even left the surface. That's roughly Mach 10, something we've never even come close to achieving at anywhere close to sea level. You'd also need to add in a lot of extra velocity, because you'd lose a lot to air friction. Building a hypersonic payload capsule is no easy task.
Then there's the practical concerns of how you'd built the thing. The size of the thing depends greatly on how much acceleration your payload can tolerate. If it were a linear accelerator, it would need to be tens of kilometers long (the last few kilometers would be passed by in about a second!). A circular one would probably need to be at least several kilometers in diameter (so that centripetal acceleration doesn't crush you when your tangential velocity is kilometers per second, increase radius). It'd all need to be superconductive, too. The closest we've ever built to something like that is the LHC, which can impart on a cluster of protons, in a vacuum, at liquid helium temperatures, roughly the equivalent energy of a fast-pitched baseball. The actual acceleration is done based on electrical charge, which makes it pretty easy - the big magnets just steer the beam in a circle. A payload is electrically neutral, so the acceleration would be done magnetically (like this new aircraft catapult), which is frankly more difficult to do.
So, in short,you probably could do it, but it involves enormous technical challenges, a generation or two's worth of R&D, and probably tens if not hundreds of billions of dollars in capital costs. Even then, your payload capacity to LEO may be very small, and it may not be physiologically safe for humans.
What would probably be a better use of technology would be a 747-sized catapult that could gently accelerate (or assist in accelerating) large aircraft down an airport runway up to speeds of, say, 300 km/h.
The majority of the molten salt is at ground level: the top of the tower is just where it is heated. If you look at the images accompanying the article, you'll see that in their schematic. Also, you'll see an image showing the two heat storage tanks down on the ground: they are actually a bit below grade, and there is a bowl-like structure surrounding each in case of a release.
Probably it's a typo, and they meant to write "name" with reference to Calligula, but what the hell is a "neme". Is that some new-fangled internet term for a name-meme? And what the hell is that supposed to mean?
Yes, I googled it, and got no satisfaction. YMMV.
The authors of the report say as much in their summary:
And while both the article summary and the report itself stress the need to provide alternate formats alongside (or in place of) PDF, the full report is scant on details or comparative tests of other formats. HTML and RTF seem decent options, as they permit some text formatting options (but are not wedded to them) and are platform-independent. But when you start adding graphics to the mix (as sometimes must happen) their portability tanks. They also cannot prevent the same problem that plagues PDFs: when some dipshit just scans a document and spits out an image-only file.
(PS - would it have killed the submitter and editors to link to the main report page, rather than only to a second-hand link from ITNews Australia?)
The results look an almost identical to the kind of data I get from the NextEngine 3D laser scanner. To create a 3D surface, the device sweeps a laser across the object in front of it. The laser sweeps a vertical line, and shines on the (arbitary) surface of the object in front of it. Stereo cameras capture the shape of the laser line from different angles, and software is able to extract the 3D surface from there. An accompanying visible light image from one camera or the other is used to apply a "skin" to what is otherwise a wireframe. By using a laser and taking its time, rather than broadcasting an infrared grid of fiducial dots, the results are very good: sub-millimeter accuracy is easy, though for handheld objects, not people in a room. Similar technology can be used for very large scale models, such as the I-35W bridge collapse in Minneapolis.
Wait, I thought fusion was still (perpetually) a few decades away from viability.
Actually, what confuses me is the apparent contradiction in the summary: how is it that the requirements mandate a solid-rocket design, yet NASA is also considering all-liquid designs? I wouldn't put it past NASA to do contradictory things, but I would hope the summary-writer and editors could explain things better.
I've got it! A solid liquid design! What will those guys think of next!
What shall we consider the when we talk about a satellite being "largest?" As we all know, physical size doesn't matter all that much in space. Weight (or rather, mass) in orbit is probably a greater achievement. The ISS probably takes the cake by both measures, though definitions and semantics make for a tricky comparison.
The Shuttle, empty and floating in orbit, has a mass of roughly 2000 metric tons. Perhaps, for semantics, we won't consider that a satellite, either.
For more conventional satellites (i.e., hunks of unmanned electronics that do some useful purpose for years on end), I think the heaviest ever was the Compton Gamma Ray Observatory at 17 metric tons, which was sent aloft using the Shuttle, because it was too heavy for any rocket at the time.
Cassini-Huygens had a launch weight of nearly 6 metric tons, and also used a Titan 4 Heavy. Considering they launched it all the way to fucking Saturn, that also seems a bigger achievement than this latest spy satellite.
Just wait until we have a solar sail testbed out there with a 1-km span, but with a mass of just 10 kg.