The PSI doesn't change. If you change the diameter of the vessel, and the diameter of the wall appropriately to scale, then it's 15PSI regardless. If you increase the pipe diameter of a pipe that's right at tolerance, but leave the wall thickness the same, and pull a vacuum on it: It crushes. Because PSI is Pounds per Square Inch. And you are increasing the square inches present.
Do you know how expensive a sumarine hull is? It's coated in inch-thick steel and constant structural beams runinng through it so heavily that you can barely crawl through a bulkhead. do you think we can afford to place a 2000 mile long submarine-hull along the length of California? The longest tunnel in the world is 58km long. The hyperloop from LA to SF is roughly ten times that distance. It is not cost effective to make a tunnel strong enough to with stand the forces necessary and be cost competitive with the airlines. And for a FAR lower price, you could build a passenger high-speed rail train that goes at 200-250mph through regular atmosphere.
So you're not far off. My concern is primarily hitting crush pressure via a semi-truck slamming into either the tube or a support structure. You'd have to design something crazy beefy to prevent the situation where the thing either squashes like a tin-can, or the biggest concern, to tear open at an expansion joint. Such a tear could let in a great volume of air in very quickly. In vacuum chambers, they typically use "bellows" for this. They'd have to design one that was above and beyond anything built before in ways that I can't even imagine despite my years working with high-vacuum tech, and make it cheap enough to put it every 25 yards or so. Until I hear evidence that this can be done at a reasonable budget, I fear that this project is a pipe dream.
And if you scale the diameter of pipeline down to stock-pot diameter, guess what size you get? Stock-pot thickness metal. And I realize that metal doesn't scale perfectly, regardless, If it's fresh round tube with good welds, it'll hold a vacuum, but if you dent it, it is likely to crush. So they're going to have to engineer something entirely different, and most importantly, figure out how to make it cheap; because the distance they are proposing is really really long, and they don't want to have to charge $1000 per ticket. They've got to be competitive with airline prices or this is a waste.
I don't disagree, but designing something with such a massive surface area that can hold a near vacuum is supremely hard, extremely fragile, and yet they are patting themselves on the back for sending an unmanned car down a track at 1/4 their proposed speed, when that's remotely one of the difficult parts. I haven't once heard them talk about the problems of tube design, or the beginnings of safety measures, and I only heard them begin to mention starting on the problem of passenger feed-through (getting passengers in and out of the pressurized vessel). Their test track is currently a raw steel tube with no expansion joints. To me that's a horrible way to spend money. They should be doing small scale testing and computer modeling to figure out ways to solve those big problems first. That's the way normal engineering projects work.
Vents and extra space or not, you're still potentially crashing into a wall of air, traveling at something approaching the speed of sound, while you travel at 700mph in the opposing direction. Even with sensors that react at the speed of light. Even with ideal-on-paper brakes, you can't deccelerate the human body fast enough to react to this. It kills the passenger.
There's a difference between tensile strength and compression strength. And PSI is based on area. The area of a pipeline is usually either very narrow or the pipe is very thick. This pipe is going to be extremely wide. So that PSI turns into quite a lot of force. I once tried to pull a vacuum on a stock-pot and it crushed on me. That was only 10'' diameter. So sure, if you made the entire tube with 1/2'' steel, you'd be fine. But the project would also cost like 100 billion dollars to go from SF to San Diego.
Not exactly, but certain Amateur radio bands allow for packet-radio, some are reserved for voice only, and some used to be for morse-code only, but I think they did away with that. Morse has advantages over voice in emergencies in that it can be understood more easily than voice despite an extremely noisy/weak signal. But you get similar benefits by turning the baud-rate way down in packet-radio. Also, morse is no longer required for a license, so it might be more difficult to find people who can decipher you.
Yes, I am aware of that. I've been an amateur radio operator for 20 years. And I spent four years writing software for wireless telephone basestations. When we had a screwup resulting in things like taking an entire island off of global telephone phone network, leaving things stranded without a software-patch, we'd just use a sat-phone.
3 people resigned from CNN as a result of a retracted article. I'm unable to find any evidence of anyone being fired or resigning from New York Times for fabricating stories. The difference between CNN and actual fake news sites is that when CNN learns that it made a mistake, they issue a retraction. Actual fake news sites don't care and leave it up.
Do you have any evidence that they didn't/don't primarily write articles that favored Trump? Because most fake-news articles I've seen shared on FB have been pro-Trump stuff.
Still a pretty nasty vulnerability, and not super usual to have one that spans across OSs like this. Leaving this sort of interface open to buffer overflows all the way down at the link-layer is a rookie mistake, and rather alarming to find that it's not implemented with a bit more oversight. Decent static analysis can usually detect these sort of errors.
The problem here is that Trump is arbitrarily picking and choosing who has the capability to voice their grievances. I really don't see the courts approving of that. This could be resolved the same way corporations resolve these issues: establish a WH policy regarding access and enforce it, preferably independently, meaning Trump doesn't hit the block button himself. Simple example: If your messages approach the threshold of harassment as given for a public figure, then your account can be blocked. This would venture into unprotected speech, and blocking an account committing it would be reasonable. Although this could likely still get lawsuits in order to get a ruling on whether or not a block was reasonable in any given situation. Alternatively, he could resign, and block whoever he wants, that'd work too. Or delete his Twitter; another valid solution. Or hey, both would be great too.
Not really. As mentioned. An antenna directly behind your antenna won't be able to pick up the signal. But it's pretty difficult to be perfectly behind an antenna in that manner. Shifted off to one side or the other by half a wavelength or so and you get signal. If you're a far distance away from the first antenna, this can just be a very small offset.
I'm trying to find more information about this but I think I just don't know the right search terms. Could you give me any more detail about this, or name the law or link me to a source? I'm not doubting you, it just sounds fascinating and I'd like to learn more.
As a matter of fact, I'm an engineer and fabricator. I know metalworking, machining, welding, blacksmithing, fiberglass composites, autobody restoration, greensand pattern-making, and metalcasting, resin-casting, and moldmaking. When I fix things you can't tell it was ever broken. I'm a very positive person and I know that amazing things can be done. I built my own high-vacuum chamber. High-vacuum means it has both regular rotary-vane roughing pump and a high-power diffusion pump that brings the vacuum so low that it cannot be measured by mechanical means. On my first attempt, I didn't bother to do the math, and went with a stock-pot whose walls were too thin. The thing crushed on me on my second pumpdown test. It went off like a gunshot. I'm intimately aware with the forces involved that must be appreciated to make this feasible. The mechanical feedthrough (that's the technical term) problem is solvable, but absolutely nontrivial. So far, all they've done is put a maglev train in a vacuum chamber. No one has ever doubted that this could be done. We've had maglev trains carrying actual passengers since 1978. A proper engineering endeavor would start demonstrating this idea in small-scale. It saves tons of money to solve as many problems as possible in the small scale and only go to full-scale when the physics demands it. These guys went full-scale early because they've got $150 million dollars to play around with, and because they want still more money, and so they're doing full-scale demos because they look more impressive. But they've yet to solve any new engineering challenge. They try to tout this as their kitty-hawk moment. But it isn't. It's an unmanned person sized maglev in a tube. Send a human down it safely and I'll be impressed. Design a tube that can withstand a car crashing into it without collapsing, made from materials that can be cheap enough to be feasible and I'll be impressed. Or design a feasible solution for emergency exits. Or demonstrate a bellows mechanism that can allow for thermal expansion and contraction that is able to flex for a year or more while outside in California weather and still hold a vacuum without leaking. Show me that the numbers crunch in such a way that they don't have to have a massive volume of passengers being charged $2k per ticket in order to break even.
You are mistaken. The energy must be output whether that energy is used to drive the receiver or not. If you surround one antenna attempting to receive with other antennae, yes, the center one will be blocked, but the same would be true if you used plain metal rods. You are correct that the energy isn't free, and it does come from the transmitter. It's just that modern phones use extra power to properly amplify the signal.
Meh, it's been a few months. Slashdot is required to meet a quota of over-sensationalized quackery that will never successfully develop into a viable product articles or else it loses it's news-aggregation license.
Two reasons. He swindled so much money and spent so much of it that he cannot make full restitution with his remaining funds. Absolutely, his accounts should be and were drained, but there's still remaining debts. Second, you can sometimes hide funds and play around with bankruptcy to absolve debts (IANAL, and I've heard that many of these loopholes are closed, but you know how sneaky people can be). I'm not proposing he be allowed to invest other people's money. I'm proposing that he talk to people who believe he has the secrets to success, regardless of the fact that he got caught. Because The Wolf of Wall Street taught me that those people exist (foolish thing said on purpose to indicate that I'm slightly talking out of my ass, but I still think I'm right on that).
I find myself wondering if a centrist movement doesn't evolve from this mess. Perhaps not a new political party, but a sentiment that anything that is extreme right or extreme left is probably a bad idea, and that politicians that are unable to negotiate and compromise are a hindrance to the essential flow of business.
Pizzagate was not (originally) fake news, it was a conspiracy theory. As far as anyone can tell, it was thought up by a genuine nutbar conspiracy theorist type, and then other conspiracy theorists expanded upon it. Fake news is written by people who know they are making things up (or made by bots written by people with the intent of generating fiction). Fake news did pick up on it a bit. And some people did things like faking social media screenshots or taking them unbelievably out of context for the sake of trolling or fanning the flames, but not for the sake of ad revenue.
Slashdot Mirror
The PSI doesn't change. If you change the diameter of the vessel, and the diameter of the wall appropriately to scale, then it's 15PSI regardless. If you increase the pipe diameter of a pipe that's right at tolerance, but leave the wall thickness the same, and pull a vacuum on it: It crushes. Because PSI is Pounds per Square Inch. And you are increasing the square inches present. Do you know how expensive a sumarine hull is? It's coated in inch-thick steel and constant structural beams runinng through it so heavily that you can barely crawl through a bulkhead. do you think we can afford to place a 2000 mile long submarine-hull along the length of California? The longest tunnel in the world is 58km long. The hyperloop from LA to SF is roughly ten times that distance. It is not cost effective to make a tunnel strong enough to with stand the forces necessary and be cost competitive with the airlines. And for a FAR lower price, you could build a passenger high-speed rail train that goes at 200-250mph through regular atmosphere.
So you're not far off. My concern is primarily hitting crush pressure via a semi-truck slamming into either the tube or a support structure. You'd have to design something crazy beefy to prevent the situation where the thing either squashes like a tin-can, or the biggest concern, to tear open at an expansion joint. Such a tear could let in a great volume of air in very quickly. In vacuum chambers, they typically use "bellows" for this. They'd have to design one that was above and beyond anything built before in ways that I can't even imagine despite my years working with high-vacuum tech, and make it cheap enough to put it every 25 yards or so. Until I hear evidence that this can be done at a reasonable budget, I fear that this project is a pipe dream.
And if you scale the diameter of pipeline down to stock-pot diameter, guess what size you get? Stock-pot thickness metal. And I realize that metal doesn't scale perfectly, regardless, If it's fresh round tube with good welds, it'll hold a vacuum, but if you dent it, it is likely to crush. So they're going to have to engineer something entirely different, and most importantly, figure out how to make it cheap; because the distance they are proposing is really really long, and they don't want to have to charge $1000 per ticket. They've got to be competitive with airline prices or this is a waste.
I don't disagree, but designing something with such a massive surface area that can hold a near vacuum is supremely hard, extremely fragile, and yet they are patting themselves on the back for sending an unmanned car down a track at 1/4 their proposed speed, when that's remotely one of the difficult parts. I haven't once heard them talk about the problems of tube design, or the beginnings of safety measures, and I only heard them begin to mention starting on the problem of passenger feed-through (getting passengers in and out of the pressurized vessel). Their test track is currently a raw steel tube with no expansion joints. To me that's a horrible way to spend money. They should be doing small scale testing and computer modeling to figure out ways to solve those big problems first. That's the way normal engineering projects work.
Vents and extra space or not, you're still potentially crashing into a wall of air, traveling at something approaching the speed of sound, while you travel at 700mph in the opposing direction. Even with sensors that react at the speed of light. Even with ideal-on-paper brakes, you can't deccelerate the human body fast enough to react to this. It kills the passenger.
There's a difference between tensile strength and compression strength. And PSI is based on area. The area of a pipeline is usually either very narrow or the pipe is very thick. This pipe is going to be extremely wide. So that PSI turns into quite a lot of force. I once tried to pull a vacuum on a stock-pot and it crushed on me. That was only 10'' diameter. So sure, if you made the entire tube with 1/2'' steel, you'd be fine. But the project would also cost like 100 billion dollars to go from SF to San Diego.
Go search for videos of tanker-cars imploding. Vacuum chambers, even when made from thick steel, can still crunch pretty easily.
Not exactly, but certain Amateur radio bands allow for packet-radio, some are reserved for voice only, and some used to be for morse-code only, but I think they did away with that. Morse has advantages over voice in emergencies in that it can be understood more easily than voice despite an extremely noisy/weak signal. But you get similar benefits by turning the baud-rate way down in packet-radio. Also, morse is no longer required for a license, so it might be more difficult to find people who can decipher you.
Yes, I am aware of that. I've been an amateur radio operator for 20 years. And I spent four years writing software for wireless telephone basestations. When we had a screwup resulting in things like taking an entire island off of global telephone phone network, leaving things stranded without a software-patch, we'd just use a sat-phone.
Real news sites use journalism techniques like fact-checking. Fake news sites do not; they fabricate falsehoods.
3 people resigned from CNN as a result of a retracted article. I'm unable to find any evidence of anyone being fired or resigning from New York Times for fabricating stories. The difference between CNN and actual fake news sites is that when CNN learns that it made a mistake, they issue a retraction. Actual fake news sites don't care and leave it up.
Do you have any evidence that they didn't/don't primarily write articles that favored Trump? Because most fake-news articles I've seen shared on FB have been pro-Trump stuff.
What are you talking about? The article doesn't make any reference to a Republican connection to the town at all.
Still a pretty nasty vulnerability, and not super usual to have one that spans across OSs like this. Leaving this sort of interface open to buffer overflows all the way down at the link-layer is a rookie mistake, and rather alarming to find that it's not implemented with a bit more oversight. Decent static analysis can usually detect these sort of errors.
Found the hammer struggling to stay relevant.
The problem here is that Trump is arbitrarily picking and choosing who has the capability to voice their grievances. I really don't see the courts approving of that. This could be resolved the same way corporations resolve these issues: establish a WH policy regarding access and enforce it, preferably independently, meaning Trump doesn't hit the block button himself. Simple example: If your messages approach the threshold of harassment as given for a public figure, then your account can be blocked. This would venture into unprotected speech, and blocking an account committing it would be reasonable. Although this could likely still get lawsuits in order to get a ruling on whether or not a block was reasonable in any given situation. Alternatively, he could resign, and block whoever he wants, that'd work too. Or delete his Twitter; another valid solution. Or hey, both would be great too.
Not really. As mentioned. An antenna directly behind your antenna won't be able to pick up the signal. But it's pretty difficult to be perfectly behind an antenna in that manner. Shifted off to one side or the other by half a wavelength or so and you get signal. If you're a far distance away from the first antenna, this can just be a very small offset.
I'm trying to find more information about this but I think I just don't know the right search terms. Could you give me any more detail about this, or name the law or link me to a source? I'm not doubting you, it just sounds fascinating and I'd like to learn more.
As a matter of fact, I'm an engineer and fabricator. I know metalworking, machining, welding, blacksmithing, fiberglass composites, autobody restoration, greensand pattern-making, and metalcasting, resin-casting, and moldmaking. When I fix things you can't tell it was ever broken. I'm a very positive person and I know that amazing things can be done. I built my own high-vacuum chamber. High-vacuum means it has both regular rotary-vane roughing pump and a high-power diffusion pump that brings the vacuum so low that it cannot be measured by mechanical means. On my first attempt, I didn't bother to do the math, and went with a stock-pot whose walls were too thin. The thing crushed on me on my second pumpdown test. It went off like a gunshot. I'm intimately aware with the forces involved that must be appreciated to make this feasible. The mechanical feedthrough (that's the technical term) problem is solvable, but absolutely nontrivial. So far, all they've done is put a maglev train in a vacuum chamber. No one has ever doubted that this could be done. We've had maglev trains carrying actual passengers since 1978. A proper engineering endeavor would start demonstrating this idea in small-scale. It saves tons of money to solve as many problems as possible in the small scale and only go to full-scale when the physics demands it. These guys went full-scale early because they've got $150 million dollars to play around with, and because they want still more money, and so they're doing full-scale demos because they look more impressive. But they've yet to solve any new engineering challenge. They try to tout this as their kitty-hawk moment. But it isn't. It's an unmanned person sized maglev in a tube. Send a human down it safely and I'll be impressed. Design a tube that can withstand a car crashing into it without collapsing, made from materials that can be cheap enough to be feasible and I'll be impressed. Or design a feasible solution for emergency exits. Or demonstrate a bellows mechanism that can allow for thermal expansion and contraction that is able to flex for a year or more while outside in California weather and still hold a vacuum without leaking. Show me that the numbers crunch in such a way that they don't have to have a massive volume of passengers being charged $2k per ticket in order to break even.
You are mistaken. The energy must be output whether that energy is used to drive the receiver or not. If you surround one antenna attempting to receive with other antennae, yes, the center one will be blocked, but the same would be true if you used plain metal rods. You are correct that the energy isn't free, and it does come from the transmitter. It's just that modern phones use extra power to properly amplify the signal.
Meh, it's been a few months. Slashdot is required to meet a quota of over-sensationalized quackery that will never successfully develop into a viable product articles or else it loses it's news-aggregation license.
Two reasons. He swindled so much money and spent so much of it that he cannot make full restitution with his remaining funds. Absolutely, his accounts should be and were drained, but there's still remaining debts. Second, you can sometimes hide funds and play around with bankruptcy to absolve debts (IANAL, and I've heard that many of these loopholes are closed, but you know how sneaky people can be). I'm not proposing he be allowed to invest other people's money. I'm proposing that he talk to people who believe he has the secrets to success, regardless of the fact that he got caught. Because The Wolf of Wall Street taught me that those people exist (foolish thing said on purpose to indicate that I'm slightly talking out of my ass, but I still think I'm right on that).
Yesterday's slashdot post on this got over 900 comments, and it was a weekend post. Do we really need another round on this topic?
I find myself wondering if a centrist movement doesn't evolve from this mess. Perhaps not a new political party, but a sentiment that anything that is extreme right or extreme left is probably a bad idea, and that politicians that are unable to negotiate and compromise are a hindrance to the essential flow of business.
Pizzagate was not (originally) fake news, it was a conspiracy theory. As far as anyone can tell, it was thought up by a genuine nutbar conspiracy theorist type, and then other conspiracy theorists expanded upon it. Fake news is written by people who know they are making things up (or made by bots written by people with the intent of generating fiction). Fake news did pick up on it a bit. And some people did things like faking social media screenshots or taking them unbelievably out of context for the sake of trolling or fanning the flames, but not for the sake of ad revenue.