consider what I said: they'd played the Pixies six times, in eight years. I grant you that's more than most mainstream stuff, but that's still pretty sparse. I think that somafm.com plays the pixies on their indie pop rocks feed, however, and you have a chance of hearing them once a week, rather than once a year. And yes, I *love* the Pixies. One of the best shows I ever saw was last year when they toured. (I saw them three times, but only one really stood out.)
Yeah, they're Icelandic, and they tour with a couple other Icelandic groups. If you ever get a chance, go. That might be the best concert I've ever seen. When I got to see The Bel-Aires, The Velvet Underground, and The Pixies at Red Rocks, that was stupendous, but Sigur Ros was just amazing, too, and they didn't have a spectacular venue. One of the things that they do is they play things with bows -- they don't pluck guitars, they bow them. Also tables, music stands, saws, and anything else, and they manage to extract the most amazing sounds from them. They're truly amazing musicians, and I'm trying to learn Icelandic in part because of them.
As I said, I've walked a total of 4km on that particular railroad, and there isn't a gap anywhere. So, uh, whatever.
Likewise, as I said in another bit of this thread, my understanding of the space elevator is that the fibers are not intended to be 36,000 miles long. They're intended to be meters long, and attached one-to-another by adhesives, just as current composite construction is performed.
The one I listen to the most -- radio1190.org, I believe they webcast -- has like 5000 watts of power to the transmitter during the day (compared to 50,000-100,000W on the commercial ones around here) and because of some weird regulation, they drop down to 100W, yes one hundred, after dark. And it's AM so it's all crackly. But that's okay: it sounds a little like old vinyl and it's the weirdest stuff.
For the record, groups I've found because of them, that I recommend: Sigur Ros, Mogwai, Electralane, Rasputina, Slim Cessna's Auto Club, 16Horsepower, Arab Strap, Belle & Sebastian, Black Heart Procession, God Speed You Black Emperor, Boards Of Canada, Beauty's Confusion, Death In Vegas, Jane Jensen, Xenofobix, Karsh Kale, Underworld, among many others. Plus, they were playing Modest Mouse 7 years ago. Ditto Gogol Bordello. They were playing Arcade Fire two weeks after their first album came out.
You have to sift through a lot of junk -- which is one of the useful things that eg Clear Channel does -- but on the other hand, you find a bunch of stuff that you, personally, think is just wonderful, that many other people wouldn't, which is why the big stations don't play it. They're least-common-denominator, and piddly little 5000W stations can play two hours of '70's funk or have a whole show just doing trip-hop and succeed.
Which, by the way, is why I think there's widespread corporate opposition to internet radio: it fragments the user base because everyone is off listening to the stuff they REALLY LOVE rather than the broad-market swill, but there isn't enough money in any of those little tiny markets to fuel up the advertising juggernaut that corporations love so much.
I still listen to radio: two little college stations that, between them, have played three songs I've heard on mainstream radio, and that's after two years of listening. (Thomas Dolby's "Airwaves", Kate Bush's "Running Up That Hill", and the Pixies, "Where Is My Mind", for the record. Neither radio station will accept requests for "Where Is My Mind" because both say, and I quote, "We play that ALL THE TIME: we've aired that six times in the last eight years!") As a result, I've found out about 30 dozen, conservatively estimating, new bands I would never have heard on Clear Channel. Rock on.
I haven't gotten to watch resistance-welding of tracks, and didn't know they did it that way. I'd always assumed they just thermite-welded the new material.
Your summary's correct. The mold is ceramic, it fits on the track fairly tightly along the web but not as much on the head or the butt of the track, and it burns hot and slow when they set it off. Then they put a long alignment/grinder setup on the track and run it back and forth and it grinds the surface down to the point where if I didn't know the join point, I couldn't tell it had been joined.
It's not too hard to build your own spotwelder/resistance welder. It won't do bandsaw blades, or at least not well enough to trust them, but it'll do small, strong welds. I made mine out of an old arcwelder: ripped out the secondary and rewound it, machined a couple copper electrodes. It does a great job.
My understanding of the space cable technology was that they were trying to do essentially exactly the same thing as the railroad: make strands a few meters long, then join them.
Basically, what you're noticing here is a -- or the -- distinguishing characteristic of Protestant tradition vs. Catholic tradition. Catholics are top-down. God talks to the Pope, who talks to the Cardinals, who talk to the bishops, who talk to the priests, who talk to the people, and that's how truth moves. The Protestant tradition is (supposed to be) bottom-up: everyone is a priest, everyone has equal access to the word of God (hence the proliferation of vernacular translations of the Bible -- dude, I ran into Today's New International Version the other day. Talk about a self-dating name...) So, yeah, Baptists can make up anything they want and if they can demonstrate to their own satisfaction that it's consistent with the Bible, hey, off they go. My mom, for instance, is of the opinion that "God loves everyone" -> everyone is forgiven -> everyone goes to heaven -> there is no hell. While she's at it, for extra credit, she claims that Satan is an allegory for selfishness and that the concepts of heaven and afterlife are both constructs to give a sense of permanence to the idea of reputation: if you lived a good life, and helped others, your name will live on after death, and that's heaven. She doesn't have a church following her ideas, not surprisingly, but she's a Baptist and one in good standing; she can support her belief system by talking about the Bible, and that's all that's required.
The irony, to my mind, is that most Southern Baptists, who are in my opinion a recidivist population of Protestants, are creed-based and to a large extent top-down: they come up with a belief system with specific items, and then everyone has to believe that. That seems, to me, to betray the whole concept behind Luther and his contemporaries.
For the record, some railroads are. Watch track crews thermite-welding railroad tracks together some time. It's pretty impressive. The tracks 10 yards from my workplace are one continuous piece of metal for more than 2 km in either direction, coz that's as far as I've walked on them.
I'm not arguing that a credit history has some validity -- it's a reasonably good indicator the person pays bills on time. So are utility bill records. But it's also an indicator of behavior patterns if a person has lots of money sitting around gaining interest. They sure were avidly interested in my investments. They wanted to see exactly how much I had and what sorts of investments I'd made. So, they very definitely cared what sorts of assets I had, because it helped establish that I was a person who could afford to make payments even if I didn't have a regular source of income, much less whether I'd used credit in the past. Their business plan is profit by loaning money. They do that by trying to get as much money out of people as possible, and a person who already has money is likely a good risk, just as a person who always pays bills is a good risk.
Pueblo sure could use it. Interesting factoid: a lot of short-haul trucks are/were made by companies that also did aircraft. Grumman used to do the majority of USPS trucks right beside their AA series of light aircraft, for instance. Another interesting factoid: Fort Collins has been, for years, the home of Forney Industries, the people who were responsible for the Forney Museum. Forney builds welding stuff, and in the Depression, old man Forney would trade welding equipment for antique cars, hence the Forney Museum. One of his acquisitions was an Ercoupe aircraft, and he was so fascinated by it that he bought the type certificate for Ercoupes and made them in Fort Collins for several years. On old maps, circa 1955, there was an airstrip in north Fort Collins, just north of Mulberry, for the Ercoupe plant (which was right beside the still-existing Forney plant.) That's a digression, but the point being, even little rural towns (which FC sure was at that point) could crank out assembly-line formed-sheet-metal construction like short-haul trucks. As such, I think it's much more likely those sorts of jobs would end up in Kansas or Oklahoma, both of which have significant sheet-metal-fab transport manufacturing facilities still sitting around, running at half capacity.
I know a guy who drives a Rolls-Royce Ferret, a 1950's armored car legal for street driving. It's the cheapest Rolls you can buy, costing well less than any new SUV. He said he's crushed two SUV's in crashes; in neither case was the Ferret visibly scratched. (That's what 3/4" armor plate will do for you...) So, there *is* some truth in the get-a-bigger-car methodology. It's just that, as it so happens, SUV's are much more likely to roll in crashes among other problems, so SUV drivers are very likely increasing danger to *themselves* as well as others with their arms race.
For trucks == long-haul semi-trailer crossing mountain ranges, yes, the range and power issues are insurmountable, currently. For trucks == UPS, USPS, Pepsi/Coke/Coors local distribution, all-electric or hybrids would be superb. Yes they have to be economical, but the social good that would come from mass replacement of these is such that government incentives could offset their increased cost. Or, if you want a value-neutral solution, raise the licensing tax on non-hybrid small trucks, and use that to lower the license tax on hybrids and electrics.
As for the long-haul semi-trailer crossing mountain range trucks, well, diesel-electric locomotives are hybrids, and they've spent 70 years being vastly more efficient, if not more convenient, than trucks.
One could say the same thing of gasoline engines: sure, they're fancy, but you have to wait 100 million years to get the fuel into the tank! Which is to say: if you can't get the amps in through a cable, put the amps in via battery swap.
I had the same experience: no credit history whatsoever, even though I owned a house outright and had another house-worth of money in stock. I managed to get a mortgage, but only because they A: called all the companies I paid bills to (utility, phone, car insurance) to check my payment history, and B: because I could buy the house outright if I wanted to, so they knew I was financially solvent. If either of those had come up short, no house for me.
Having a credit history isn't a bad idea, unfortunately. My brother has a credit card that gives him money back, somehow, and he uses it for utilities/phone, pays it back at the end of each month, has a great credit rating, and gets like a 4% discount, effectively, on all his bills.
And if your max connection rate is 28.8kbps they can charge you $2000/gigabyte and you won't care because you won't ever use it. Services like YouTube are completely irrelevant at that kind of speed.
You *are* screwed because you have enough bandwidth to run up some huge bills, but not enough to do what you'd like. But I bet you wouldn't trade that for near-unlimited transfer quota that you can't use because it's too slow.
1. Mac Mini: $700. I *believe* they can access the Internet.
2. My mom, brother, girlfriend (and, soon, aunt) are using linux. It's not user-friendly, but once I set it up, it works and they don't have to screw around with it.
For the record, my mom has two houses in the US, in Colorado -- a fairly high-income and technically-oriented-jobs state -- and at neither house can she get better than modem access. At one, I've never seen modem speeds better than 28.8kbps. So 512kbps would be 20 times faster than the max rate she gets, so I would absolutely consider that broadband. Which is to say: quit yer complainin'.
I had an interesting discussion once with a guy who was a designer for the national aerospace plane project, high-ranking USAF as well as NASA. We spent about an hour talking about all sorts of different aspects: fuel, high-temp skins, control systems. The only thing he wouldn't talk about was how it took off: how it produced thrust with zero V. I spent some time thinking about it and reading about it. These are some things I know: the system had a single duct going through the whole plane, and it had multiple injection points for fuel. They'd inject at one area in one realm of flight, and another at another, to maximize thrust and also because at full (proposed) speed it actually took the entire length of the craft just to get the hydrogen to diffuse enough with the oxygen to combust smoothly. So, at lower speeds it injected midbody and at high speeds, very near the nose itself. Couple that with the old jet trick of starting one jet's engine by parking another jet right in front of it and blasting the front jet's exhaust down the dead jet's intake to get the compressors spinning up high enough, which was used with success to get engines started... I bet what they were planning on doing was injecting fuel at the nose at high pressure, pointing backwards, and igniting it, and using the resultant backwards airflow to get the second ignition point at midbody running, so essentially it's operating as a ramjet using its own exhaust to provide the ram air pressure.
Probably nobody will ever read this, but I had a nice long chat one time with an engineer who worked for NASA and was a fairly high-ranking officer in the USAF as well. He was working on the National Aerospace Plane and he felt that the leading-edge materials were not overwhelmingly difficult to solve. They were doing a lot of work with carbon-carbon matrix stuff that forced carbon out -- bled it -- to form continuously ablating surfaces, and had some neat systems for forcing hydrogen slush, a mixture of solid and liquid hydrogen, through the surfaces to simultaneously cool them and vaporize the slush for use in the fuel system. They were more concerned about stability and the ability to get the thing to produce thrust at zero velocity so it could take off, than they were with the craft burning up.
By the way, not that any of us know what we're talking about, but a lot of the people talking about the Aurora are claiming it has some sort of pulse-jet or non-steady-state engine, based on visual sightings and pictures of the contrails. I've seen something, well before I read about this, that fit the descriptions I've since read of an aircraft with a non-steady-state jet engine, although I have no idea what it was. If the Aurora was the B-2, then there's likely something else out there that military plane spotters are calling the Aurora now.
>When he says "The adhesive needs to be hardened, so the components won't fall off" he means the solder paste is melted then allowed to cool with the components in it, thereby attaching the components to the PCB electrically and mechanically.
This is a late reply, but one interesting thing about the pick-and-place machines is that they're putting several G's of acceleration laterally on the boards when they're placing components. What this means is that even though the board has solder paste on all the pads, and the components are stuck in the solder paste, if any part isn't set well or even just heavy or with a high center of gravity -- particularly big tantalum capacitors -- it'll come loose because of the lateral acceleration and will very rapidly clean off the rest of the board as it bounces around. Then you have to pull the board and scrape off all the components, wash it, and start it over, and all those components are wasted because it's absolutely not worth the effort to sort them.
So what they do is, for some boards or sometimes just for some components, they put down little dabs of contact adhesive on the board after solder stencil but before pick-n-place, and that'll keep the big components down on the board. Then all the components are placed, and then it runs through the reflow oven (that melts the solder paste and permanently attaches the components to the board) and then, depending on the design, through a solder-wave to work any through-hole components, and then maybe even another trip through soldermask/pick-n-place to load the other side of the board. If you're careful you can get it through the reflow ovens a second time to do the backside of the board, without losing all the parts on the frontside of the board.
But to someone who is looking at a mass of unreadable data, it *looks* encrypted. To be more semantically precise: all communication is encrypted. The only question is whether the recipient has the decryption codec installed. 'blue' means photons of a particular wavelength, and each of the words in that definition are, themselves, defined in terms of other words, all of which relate to underlying concepts, right? so without a hook into the language, you'd be listening to gibberish. Consider the use of Navajo in WWII for secret communication: it was an encryption standard that one side knew and the other side didn't. The Navajo didn't consider their language encryption: it was just their language. But the Japanese who were listening thought it was. Same goes for any filesystem you can't read: it's encrypted, functionally speaking.
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consider what I said: they'd played the Pixies six times, in eight years. I grant you that's more than most mainstream stuff, but that's still pretty sparse. I think that somafm.com plays the pixies on their indie pop rocks feed, however, and you have a chance of hearing them once a week, rather than once a year. And yes, I *love* the Pixies. One of the best shows I ever saw was last year when they toured. (I saw them three times, but only one really stood out.)
Yeah, they're Icelandic, and they tour with a couple other Icelandic groups. If you ever get a chance, go. That might be the best concert I've ever seen. When I got to see The Bel-Aires, The Velvet Underground, and The Pixies at Red Rocks, that was stupendous, but Sigur Ros was just amazing, too, and they didn't have a spectacular venue. One of the things that they do is they play things with bows -- they don't pluck guitars, they bow them. Also tables, music stands, saws, and anything else, and they manage to extract the most amazing sounds from them. They're truly amazing musicians, and I'm trying to learn Icelandic in part because of them.
As I said, I've walked a total of 4km on that particular railroad, and there isn't a gap anywhere. So, uh, whatever.
Likewise, as I said in another bit of this thread, my understanding of the space elevator is that the fibers are not intended to be 36,000 miles long. They're intended to be meters long, and attached one-to-another by adhesives, just as current composite construction is performed.
The one I listen to the most -- radio1190.org, I believe they webcast -- has like 5000 watts of power to the transmitter during the day (compared to 50,000-100,000W on the commercial ones around here) and because of some weird regulation, they drop down to 100W, yes one hundred, after dark. And it's AM so it's all crackly. But that's okay: it sounds a little like old vinyl and it's the weirdest stuff.
For the record, groups I've found because of them, that I recommend: Sigur Ros, Mogwai, Electralane, Rasputina, Slim Cessna's Auto Club, 16Horsepower, Arab Strap, Belle & Sebastian, Black Heart Procession, God Speed You Black Emperor, Boards Of Canada, Beauty's Confusion, Death In Vegas, Jane Jensen, Xenofobix, Karsh Kale, Underworld, among many others. Plus, they were playing Modest Mouse 7 years ago. Ditto Gogol Bordello. They were playing Arcade Fire two weeks after their first album came out.
You have to sift through a lot of junk -- which is one of the useful things that eg Clear Channel does -- but on the other hand, you find a bunch of stuff that you, personally, think is just wonderful, that many other people wouldn't, which is why the big stations don't play it. They're least-common-denominator, and piddly little 5000W stations can play two hours of '70's funk or have a whole show just doing trip-hop and succeed.
Which, by the way, is why I think there's widespread corporate opposition to internet radio: it fragments the user base because everyone is off listening to the stuff they REALLY LOVE rather than the broad-market swill, but there isn't enough money in any of those little tiny markets to fuel up the advertising juggernaut that corporations love so much.
I still listen to radio: two little college stations that, between them, have played three songs I've heard on mainstream radio, and that's after two years of listening. (Thomas Dolby's "Airwaves", Kate Bush's "Running Up That Hill", and the Pixies, "Where Is My Mind", for the record. Neither radio station will accept requests for "Where Is My Mind" because both say, and I quote, "We play that ALL THE TIME: we've aired that six times in the last eight years!") As a result, I've found out about 30 dozen, conservatively estimating, new bands I would never have heard on Clear Channel. Rock on.
I haven't gotten to watch resistance-welding of tracks, and didn't know they did it that way. I'd always assumed they just thermite-welded the new material.
Your summary's correct. The mold is ceramic, it fits on the track fairly tightly along the web but not as much on the head or the butt of the track, and it burns hot and slow when they set it off. Then they put a long alignment/grinder setup on the track and run it back and forth and it grinds the surface down to the point where if I didn't know the join point, I couldn't tell it had been joined.
It's not too hard to build your own spotwelder/resistance welder. It won't do bandsaw blades, or at least not well enough to trust them, but it'll do small, strong welds. I made mine out of an old arcwelder: ripped out the secondary and rewound it, machined a couple copper electrodes. It does a great job.
My understanding of the space cable technology was that they were trying to do essentially exactly the same thing as the railroad: make strands a few meters long, then join them.
Basically, what you're noticing here is a -- or the -- distinguishing characteristic of Protestant tradition vs. Catholic tradition. Catholics are top-down. God talks to the Pope, who talks to the Cardinals, who talk to the bishops, who talk to the priests, who talk to the people, and that's how truth moves. The Protestant tradition is (supposed to be) bottom-up: everyone is a priest, everyone has equal access to the word of God (hence the proliferation of vernacular translations of the Bible -- dude, I ran into Today's New International Version the other day. Talk about a self-dating name...) So, yeah, Baptists can make up anything they want and if they can demonstrate to their own satisfaction that it's consistent with the Bible, hey, off they go. My mom, for instance, is of the opinion that "God loves everyone" -> everyone is forgiven -> everyone goes to heaven -> there is no hell. While she's at it, for extra credit, she claims that Satan is an allegory for selfishness and that the concepts of heaven and afterlife are both constructs to give a sense of permanence to the idea of reputation: if you lived a good life, and helped others, your name will live on after death, and that's heaven.
She doesn't have a church following her ideas, not surprisingly, but she's a Baptist and one in good standing; she can support her belief system by talking about the Bible, and that's all that's required.
The irony, to my mind, is that most Southern Baptists, who are in my opinion a recidivist population of Protestants, are creed-based and to a large extent top-down: they come up with a belief system with specific items, and then everyone has to believe that. That seems, to me, to betray the whole concept behind Luther and his contemporaries.
>Roads and railroads aren't unitary either.
For the record, some railroads are. Watch track crews thermite-welding railroad tracks together some time. It's pretty impressive. The tracks 10 yards from my workplace are one continuous piece of metal for more than 2 km in either direction, coz that's as far as I've walked on them.
I'm not arguing that a credit history has some validity -- it's a reasonably good indicator the person pays bills on time. So are utility bill records. But it's also an indicator of behavior patterns if a person has lots of money sitting around gaining interest. They sure were avidly interested in my investments. They wanted to see exactly how much I had and what sorts of investments I'd made. So, they very definitely cared what sorts of assets I had, because it helped establish that I was a person who could afford to make payments even if I didn't have a regular source of income, much less whether I'd used credit in the past. Their business plan is profit by loaning money. They do that by trying to get as much money out of people as possible, and a person who already has money is likely a good risk, just as a person who always pays bills is a good risk.
Pueblo sure could use it. Interesting factoid: a lot of short-haul trucks are/were made by companies that also did aircraft. Grumman used to do the majority of USPS trucks right beside their AA series of light aircraft, for instance. Another interesting factoid: Fort Collins has been, for years, the home of Forney Industries, the people who were responsible for the Forney Museum. Forney builds welding stuff, and in the Depression, old man Forney would trade welding equipment for antique cars, hence the Forney Museum. One of his acquisitions was an Ercoupe aircraft, and he was so fascinated by it that he bought the type certificate for Ercoupes and made them in Fort Collins for several years. On old maps, circa 1955, there was an airstrip in north Fort Collins, just north of Mulberry, for the Ercoupe plant (which was right beside the still-existing Forney plant.) That's a digression, but the point being, even little rural towns (which FC sure was at that point) could crank out assembly-line formed-sheet-metal construction like short-haul trucks. As such, I think it's much more likely those sorts of jobs would end up in Kansas or Oklahoma, both of which have significant sheet-metal-fab transport manufacturing facilities still sitting around, running at half capacity.
I know a guy who drives a Rolls-Royce Ferret, a 1950's armored car legal for street driving. It's the cheapest Rolls you can buy, costing well less than any new SUV. He said he's crushed two SUV's in crashes; in neither case was the Ferret visibly scratched. (That's what 3/4" armor plate will do for you...) So, there *is* some truth in the get-a-bigger-car methodology. It's just that, as it so happens, SUV's are much more likely to roll in crashes among other problems, so SUV drivers are very likely increasing danger to *themselves* as well as others with their arms race.
For trucks == long-haul semi-trailer crossing mountain ranges, yes, the range and power issues are insurmountable, currently.
For trucks == UPS, USPS, Pepsi/Coke/Coors local distribution, all-electric or hybrids would be superb. Yes they have to be economical, but the social good that would come from mass replacement of these is such that government incentives could offset their increased cost. Or, if you want a value-neutral solution, raise the licensing tax on non-hybrid small trucks, and use that to lower the license tax on hybrids and electrics.
As for the long-haul semi-trailer crossing mountain range trucks, well, diesel-electric locomotives are hybrids, and they've spent 70 years being vastly more efficient, if not more convenient, than trucks.
One could say the same thing of gasoline engines: sure, they're fancy, but you have to wait 100 million years to get the fuel into the tank! Which is to say: if you can't get the amps in through a cable, put the amps in via battery swap.
I had the same experience: no credit history whatsoever, even though I owned a house outright and had another house-worth of money in stock. I managed to get a mortgage, but only because they A: called all the companies I paid bills to (utility, phone, car insurance) to check my payment history, and B: because I could buy the house outright if I wanted to, so they knew I was financially solvent. If either of those had come up short, no house for me.
Having a credit history isn't a bad idea, unfortunately. My brother has a credit card that gives him money back, somehow, and he uses it for utilities/phone, pays it back at the end of each month, has a great credit rating, and gets like a 4% discount, effectively, on all his bills.
And if your max connection rate is 28.8kbps they can charge you $2000/gigabyte and you won't care because you won't ever use it. Services like YouTube are completely irrelevant at that kind of speed.
You *are* screwed because you have enough bandwidth to run up some huge bills, but not enough to do what you'd like. But I bet you wouldn't trade that for near-unlimited transfer quota that you can't use because it's too slow.
terrorists, drug dealers, kidnappers, and child pornographers.
Incest *rocks*. Or something... good catch there, in any case.
>because that's a bald-faced lie. (Anyone know how to translate that concept into Washingtonese?)
"marketing" or "advertising" or "spin" or "public relations" comes to mind.
1. Mac Mini: $700. I *believe* they can access the Internet.
2. My mom, brother, girlfriend (and, soon, aunt) are using linux. It's not user-friendly, but once I set it up, it works and they don't have to screw around with it.
For the record, my mom has two houses in the US, in Colorado -- a fairly high-income and technically-oriented-jobs state -- and at neither house can she get better than modem access. At one, I've never seen modem speeds better than 28.8kbps. So 512kbps would be 20 times faster than the max rate she gets, so I would absolutely consider that broadband. Which is to say: quit yer complainin'.
I had an interesting discussion once with a guy who was a designer for the national aerospace plane project, high-ranking USAF as well as NASA. We spent about an hour talking about all sorts of different aspects: fuel, high-temp skins, control systems. The only thing he wouldn't talk about was how it took off: how it produced thrust with zero V.
I spent some time thinking about it and reading about it. These are some things I know: the system had a single duct going through the whole plane, and it had multiple injection points for fuel. They'd inject at one area in one realm of flight, and another at another, to maximize thrust and also because at full (proposed) speed it actually took the entire length of the craft just to get the hydrogen to diffuse enough with the oxygen to combust smoothly. So, at lower speeds it injected midbody and at high speeds, very near the nose itself.
Couple that with the old jet trick of starting one jet's engine by parking another jet right in front of it and blasting the front jet's exhaust down the dead jet's intake to get the compressors spinning up high enough, which was used with success to get engines started...
I bet what they were planning on doing was injecting fuel at the nose at high pressure, pointing backwards, and igniting it, and using the resultant backwards airflow to get the second ignition point at midbody running, so essentially it's operating as a ramjet using its own exhaust to provide the ram air pressure.
Probably nobody will ever read this, but I had a nice long chat one time with an engineer who worked for NASA and was a fairly high-ranking officer in the USAF as well. He was working on the National Aerospace Plane and he felt that the leading-edge materials were not overwhelmingly difficult to solve. They were doing a lot of work with carbon-carbon matrix stuff that forced carbon out -- bled it -- to form continuously ablating surfaces, and had some neat systems for forcing hydrogen slush, a mixture of solid and liquid hydrogen, through the surfaces to simultaneously cool them and vaporize the slush for use in the fuel system. They were more concerned about stability and the ability to get the thing to produce thrust at zero velocity so it could take off, than they were with the craft burning up.
By the way, not that any of us know what we're talking about, but a lot of the people talking about the Aurora are claiming it has some sort of pulse-jet or non-steady-state engine, based on visual sightings and pictures of the contrails. I've seen something, well before I read about this, that fit the descriptions I've since read of an aircraft with a non-steady-state jet engine, although I have no idea what it was. If the Aurora was the B-2, then there's likely something else out there that military plane spotters are calling the Aurora now.
>When he says "The adhesive needs to be hardened, so the components won't fall off" he means the solder paste is melted then allowed to cool with the components in it, thereby attaching the components to the PCB electrically and mechanically.
This is a late reply, but one interesting thing about the pick-and-place machines is that they're putting several G's of acceleration laterally on the boards when they're placing components. What this means is that even though the board has solder paste on all the pads, and the components are stuck in the solder paste, if any part isn't set well or even just heavy or with a high center of gravity -- particularly big tantalum capacitors -- it'll come loose because of the lateral acceleration and will very rapidly clean off the rest of the board as it bounces around. Then you have to pull the board and scrape off all the components, wash it, and start it over, and all those components are wasted because it's absolutely not worth the effort to sort them.
So what they do is, for some boards or sometimes just for some components, they put down little dabs of contact adhesive on the board after solder stencil but before pick-n-place, and that'll keep the big components down on the board. Then all the components are placed, and then it runs through the reflow oven (that melts the solder paste and permanently attaches the components to the board) and then, depending on the design, through a solder-wave to work any through-hole components, and then maybe even another trip through soldermask/pick-n-place to load the other side of the board. If you're careful you can get it through the reflow ovens a second time to do the backside of the board, without losing all the parts on the frontside of the board.
But to someone who is looking at a mass of unreadable data, it *looks* encrypted.
To be more semantically precise: all communication is encrypted. The only question is whether the recipient has the decryption codec installed. 'blue' means photons of a particular wavelength, and each of the words in that definition are, themselves, defined in terms of other words, all of which relate to underlying concepts, right? so without a hook into the language, you'd be listening to gibberish. Consider the use of Navajo in WWII for secret communication: it was an encryption standard that one side knew and the other side didn't. The Navajo didn't consider their language encryption: it was just their language. But the Japanese who were listening thought it was. Same goes for any filesystem you can't read: it's encrypted, functionally speaking.