>Their car was a three wheeler with no steering gear. Front wheels are fixed, rear wheel a freewheeling caster, steering by pressure differential in hub-mounted turbines.
Brilliant! So when for some reason you loose power, your vehicle is instantly set into a crazy spin and immediately veers into oncoming traffic or off the cliff along side the road! This is for people who get a thrill out constantly being on the verge of impending disaster. Their idea would be just as clever and a little more practical if they just put the two non-steerable powered wheels in the rear and the free-castering wheel in the front. Though that would still have the problem of leaving you without steering if you had a power failure for some reason. Maybe differential braking could handle that situation.
Don't bother trying to convince environmentalists that it's possible to build plants that are melt down proof. People will never again fall for the massive campaign of lies that was fed to them before Three Mile Island and Chernobyl. Trying to sell that again just ruins your credibility.
Maybe point out that Chernobyl was bad but not too terrible, especially when the cost is offset by the harms of solar panels or windmills and especially coal. Maybe point out that non-environmentalists probably won't be willing to pay for solar and wind and backup batteries, so we'll be left with coal. Coal is way worse than nuclear. Maybe point out that the waste becomes hardly a problem after a few hundred years and even if it's poorly buried it's not much to worry about, especially in those tough casks. Maybe point out that while the possibility of melt down can never be eliminated, they're much less likely with modern procedures and designs, and the environmental benefits are huge.
Grandparent was talking about the bigger Falcon 9 rocket. The Falcon 9 page quotes 37 Million for 12500 kg to low earth orbit. that's about 3000$/kg. It's like a lot of things, when you buy in bulk you save a lot of money. If they can deliver that price then it will be truly revolutionary.
I would guess that the hot exhaust is being cooled by turbulent mixing with cool air. Make sure your friend considers the possibility that at speed, there may not be nearly as much chance for mixing before the exhaust hits the tail, as there is when static, and therefore the tail may experience much more heating than it does on the ground. And also consider that whether or not the exhaust hits the tail may be exquisitely sensitive to the angle of attack or airspeed. There might be no impingement in nearly all circumstances, but he might discover some rarely used angle of attack and airspeed where the exhaust does impinge. If the exhaust is above the tail in some circumstances and below in others, then he should find that worst case angle of attack and airspeed where it impinges and test it right there. Even if he doesn't normally fly there. He should also consider impingement on the side of the fuselage during a slip. The exhaust may hit the fuselage much sooner than the tail and thus be hotter.
The idea of hiding under a desk to prevent building collapse never seemed quite right to me. It seemed to make more sense to get beside a desk or preferably some other more crush resistant object. Most school desks don't look to me like they'd be able to stop a falling roof by themselves. And even if they could themselves or collectively, it seems like being beside them would be almost as good as being under. On the other hand if you're under the desk and its legs give out, then the roof is going to press down on your desk and the desk in turn will squish you. Better to be beside the desk because the roof won't be able to crush the desk totally flat, thus there will be a small space next to the desk where the ceiling wont reach all the way to the floor.
I think the school desk manufacturers are starting to advertise their school desks as more resistant to the crushing forces of black holes in addition to nuclear blasts. School district procurement officers have called for a budget increase to pay for the stronger desks, because if it saves just one child's life... However, most engineers are skeptical of these marketing claims.
Spacefellowship.com also has a discussion area for Armadillo Aerospace where actual members of the team and even John Carmack sometimes respond to posts.
Where else do people go to discuss SpaceX?
Please join me in begging SpaceX to seed a torrent of their broadcast quality video of the launch. Mod me up to +5 so someone there will be more likely to see this plea.
>Why make a relatively paltry living as a scientist when you can make oodles of cash as a lawyer, running a business, or even to a lesser degree, writing software?
Because for some geeks prestige and riches aren't their first priority. Some are more interested in doing something fun or important. Why give up much of your life to money making activities when you can get enough money doing what you love?
I'm surprised nobody has mentioned yet that http://spacex.com/ is building a reusable manned launch vehicle right now. SpaceX already has a contract with NASA but I don't know for what. They're waiting for the Fourth of July vacation to end to launch their Falcon 1 rocket at the end of this month. Their launch manifest lists the first launch of their Falcon 9 before the end of the year.
There seems to be little appreciation of the importance of SpaceX's projects. Their Falcon 1 is supposed to have a reusable first stage and their Falcon 9 is supposed to have both a reusable first and second stage. If SpaceX can get these rockets to work they could be the huge breakthrough in launch costs that we've been waiting for. The Falcon 9 hasn't flown yet and the Falcon 1 has flown and crashed twice, but it almost got to orbit. I don't see how any other launch vehicle in the world will be able to compete with SpaceX if they can reuse their rockets. Although I guess if the Space Shuttle could mess up the economics of reuseability then maybe SpaceX can to.
>>it is good to have a sysadmin who can write programs in binary
>I'd like to meet one of these sysadmins.
My first digital electronics project was an attempt to program a PIC16F84 microcontroller. Unfortunately none of the three programmers or software that I built from downloaded schematics would work. I couldn't afford a pre-built programmer so I had to design my own. My programmer had an LED on the programming pin so I could verify every bit going in. My software was a QBasic program that pulsed a parallel port pin with each key press. I sent the entire binary programming sequence specified in the datasheet to the microcontroller bit by bit. It still didn't work. In a desperate attempt to get it to work I finally tried programming it at the low end of the specified voltage range (3V) instead of at the standard 5V. I finally determined that for some reason it wouldn't program if the supply voltage was above about 4.5V. Many months later I ordered another batch of PIC16F84s from DigiKey and to spite my careful anti-static handling they also wouldn't program above 4.5V. Admittedly the first thing I did after getting that LED flashing test program to work was to modify my programmer software to take the PIC assembler hex output instead of me having to hand compile and input the binary bit by bit.
The trick to guessing how many jelly beans or whatever are in a jar is to estimate how many beans tall wide and long the jar is and then multiply it out as if the jar was rectangular. You can then take off a little bit to adjust for a round rather than rectangular jar, but your estimate will be so inaccurate anyway that a little bit like that won't matter much anyway. You'll still be way off, but much closer than anyone that just looks at it and makes a guess.
If the items in the container are very small like grains of sand, then it may help to first estimate the width of a group of the items and then estimate how many groups wide the container is. For example it might take three grains of sand to make a millimeter and therefore 30 grains of sand to a centimeter. If a barrel is 60 centimeters wide then the barrel is about 1800 grains of sand wide. Round that off to 2000. A cube 2000 grains across would have about 2000*2000*2000 = 8,000,000,000 grains of sand.
The thing that makes estimating volumes so hard is that when the estimate of the width is cubed the error in the estimate of the width is also cubed. For example if you estimate a cube is four centimeters on a side and it is really five centimeters on a side then it will be DOUBLE the volume of your estimate.
I agree that unless the files are extremely huge or extremely numerous then storage space probably shouldn't be a concern because its cheap compared to your time and getting cheaper. But if storage space is a concern then you might look into the tiff format used by the patent office. Apparently it uses a form of lossless compression taken from fax machines and gets much better compression than many other common formats on black and white(no greyscale) documents. If it's the patent office's standard archive format then it will probably be supported for a long time. Pdf can probably use the same compression as well though. I was going to mod up someone below http://ask.slashdot.org/comments.pl?sid=593693&no_d2=1&cid=23920133 who recommended PDF/A as the only archive format to use.
I still don't think it will be long after we have computers of sufficient power that we will be able to create strong AI. Trying to create AI with the computers we have now would be like trying to rewire a mouse brain to be as smart as Einstein. You just can't do it a thousand times slower if you don't have the hardware to work with. It may be hard to develop the algorithms if you don't have the hardware to test on, or we may already have pretty much all the algorithms we need but just don't have the hardware to put them together on a large enough scale. The biggest computers of 2008 might barely be enough but they're not optimized for AI and not much of their time is likely to be spent on AI.
The most common counter argument to the above is that we haven't even matched the intelligence of insects or dogs. But actually I think we can match the intelligence of insects. We don't make good insect replicas mainly for lack of mechanical miniaturization technology. Furthermore there probably aren't very many talented researchers trying to replicate useless insect behavior. As for dogs, the machines most AI researchers use probably don't even have the computational power of a dog brain.
>The NSA can probably get VeriSign to sign anything they want.
Maybe they can. Or they could just start their own Certificate Authority and get themselves onto the list of trusted authorities that comes installed with browsers or mail software.
But either way they might be reluctant to do the MITM like that because the bogus certificate with the genuine signature could be recorded by the targets and released to the public, causing great embarrassment to the certificate authority and much degradation to the trust of the certificate system.
let me repeat my last post with better formatting.
>We have used a self signed certificate for years and hundreds of other MTAs connect to us and happily set up a encrypted session to transfer mail.
If the other Mail Transfer Agents are accepting your self signed certificate without verification, then the Swiss can just generate their own certificate and pull a man in the middle attack on any of your traffic that goes through them.
>We have used a self signed certificate for years and hundreds of other MTAs connect to us and happily set up a encrypted session to transfer mail.
If the other Mail Transfer Agents are accepting your self signed certificate without verification, then the Swiss can just generate their own certificate and pull a man in the middle attack on any of your traffic that goes through them.
>The GPL effectively restricts your freedom to sell installs at a profit
Sort of like laws against slavery restrict your freedom to sell humans at a profit. The company in this case is selling hardware along with the GPL software anyway. I think there's a place for proprietary software. And I agree it makes it harder for software developers to make profits. But I think the losses to software developers are more than offset by the benefits to software consumers. It's like a machine that puts thousands of people out of work. Overall such machines end up making everyone richer. Overall I think Free Software makes everyone richer. But again, I do believe that copyright does allow a lot of valuable software to be developed that we would all have to suffer without if there was no copyright.
The GPL only restricts your freedom in a way similar to laws that prohibit slavery are restricting your freedom to take slaves. The GPL only takes away your freedom to take away the freedom of your users and the original authors of your code.
wood has the highest tensile strength of any building material known to man based either on weight or cross sectional area.
No, steel does...
There seems to be some confusion about what tensile strength is. Tensile strength is how well a material can resist pulling, not bending or compression. A rope can show off the tensile strength of a material even though it has no bending strength or compression strength.
Even when adjusting for weight, the tensile strength of wood isn't so great compared to S-glass or carbon fiber. And when adjusting for cross sectional area, the tensile strength of wood fares even worse because it has a lot of air in its pores.
Icebike wrote >...wood has the highest tensile strength of any building material known to man based either on weight or cross sectional area.
I Think your estimate of wood is much too high. Wikipedia's article of tensile strength http://en.wikipedia.org/wiki/Tensile_strength lists pine wood at 40 MPa I know there are some woods that are significantly stronger but still.
For comparison some other tensile strengths listed in MPa are:
I was thinking that it would be foolhardy to trust that some discovery in quantum physics would not render quantum cryptography insecure. But then I realized two things. First, you can always just use QC to wrap conventional cryptography so you get the security of both. Second, conventional cryptography can be eavesdropped on and recorded to be broken someday when weaknesses or more computational power is available. With QC your communications can't even be recorded for future breaking until some new physics comes along.
The success of the X-Prize seems to have made everyone crazy about prizes to stir development. But it seems to me that the X-Prize only worked great because there were some very special characteristics about the commercial manned suborbital launch vehicle problem. I think there were two primary reasons the X-Prize was successful.
The main reason was that there was no need to develop any new technology. It was only necessary for previously developed tech to be implemented cheaply. Any great NEW technology like efficient light bulbs or a cancer cure or whatever will usually have such a huge payoff to its developer that a few extra million isn't likely to add much extra incentive. If funders think it can be done then they'll fund it even without the prize. If those who would fund it see it as a long shot then the prize won't change the equation much.
The other reason the X-Prize was successful was that it wasn't clear that a manned suborbital rocket could be profitable. Boeing or Lockheed could have easily built such a rocket. If they thought it would be profitable then why wouldn't they? Maybe they thought that anything less than a very careful and therefore prohibitively expensive development project would have left their deep pockets open to excessive liability. Again, concerns like this are not a problem for a lighting technology or a cancer cure or an efficient car technology.
Oh well, best of luck anyway. Even if these prizes are a waste at least they aren't wasting all that much in the grand scheme of things.
>You have absolutely no idea what you're talking about.
What do you mean? Are parachutes not fragile or not expensive or are they cheap to rent or do they have much better used value than I think or what? The first link from a Google search for parachute is the parachuteshop.com which lists new setups at about $4000 and a used main canopy at $1200. That leaves plenty of room for reducing cost. I'd estimate that a chute with 1/4 the area could be made of fabric four times thicker and still come in a fraction of the cost of a land chute. If touching down in a large water area you could probably dispense with the parafoil design and just go with a simple round design as well.
It occurred to me couple years ago that one of the things that makes skydiving a little expensive is the parachute. To slow a person down enough to touch down on land means the chute has to be quite large and thus quite fragile in order to be packed down small enough. Fragile chutes wear out quicker as well. So why not touch down on water instead? You could tolerate a much higher touchdown speed and thus you could use a much smaller parachute. The chute could be made thicker and sturdier and still be packed down into an acceptable size. It could be reused many more times and would retain a higher percentage of its original price when sold used. Rentals would probably be safer, cheaper, more profitable, and more popular. Also, broken legs and crashes into trees and power lines would probably be reduced. Though perhaps drownings would be unacceptably common. Getting into the sport would be much cheaper, with the airplane ride becoming the dominant cost for the first jump. Or maybe I misunderstand the economics of skydiving as it is. Have you heard of this idea before? Does it sound like a good idea?
Add a small removable hydrocarbon fuelled generator to an electric car with just enough battery capacity for your daily commute and you have a great system. Emission free and chargeable by various clean technologies for your daily commute but with extended range for occasional trips. Generators are cheap and if you leave it behind on a daily basis your car is lighter. You can power extended trips with biodiesel or ethanol. I don't see how electric will work very well for long haul trucks though.
Is this what your post seems to imply - a book about how to use unix that comes with software which only runs on windows? WTF - Who is the publisher? Microsoft Press?
Slashdot Mirror
>Their car was a three wheeler with no steering gear. Front wheels are fixed, rear wheel a freewheeling caster, steering by pressure differential in hub-mounted turbines.
Brilliant! So when for some reason you loose power, your vehicle is instantly set into a crazy spin and immediately veers into oncoming traffic or off the cliff along side the road! This is for people who get a thrill out constantly being on the verge of impending disaster. Their idea would be just as clever and a little more practical if they just put the two non-steerable powered wheels in the rear and the free-castering wheel in the front. Though that would still have the problem of leaving you without steering if you had a power failure for some reason. Maybe differential braking could handle that situation.
Don't bother trying to convince environmentalists that it's possible to build plants that are melt down proof. People will never again fall for the massive campaign of lies that was fed to them before Three Mile Island and Chernobyl. Trying to sell that again just ruins your credibility.
Maybe point out that Chernobyl was bad but not too terrible, especially when the cost is offset by the harms of solar panels or windmills and especially coal. Maybe point out that non-environmentalists probably won't be willing to pay for solar and wind and backup batteries, so we'll be left with coal. Coal is way worse than nuclear. Maybe point out that the waste becomes hardly a problem after a few hundred years and even if it's poorly buried it's not much to worry about, especially in those tough casks. Maybe point out that while the possibility of melt down can never be eliminated, they're much less likely with modern procedures and designs, and the environmental benefits are huge.
Grandparent was talking about the bigger Falcon 9 rocket. The Falcon 9 page quotes 37 Million for 12500 kg to low earth orbit. that's about 3000$/kg. It's like a lot of things, when you buy in bulk you save a lot of money. If they can deliver that price then it will be truly revolutionary.
I would guess that the hot exhaust is being cooled by turbulent mixing with cool air. Make sure your friend considers the possibility that at speed, there may not be nearly as much chance for mixing before the exhaust hits the tail, as there is when static, and therefore the tail may experience much more heating than it does on the ground. And also consider that whether or not the exhaust hits the tail may be exquisitely sensitive to the angle of attack or airspeed. There might be no impingement in nearly all circumstances, but he might discover some rarely used angle of attack and airspeed where the exhaust does impinge. If the exhaust is above the tail in some circumstances and below in others, then he should find that worst case angle of attack and airspeed where it impinges and test it right there. Even if he doesn't normally fly there. He should also consider impingement on the side of the fuselage during a slip. The exhaust may hit the fuselage much sooner than the tail and thus be hotter.
The idea of hiding under a desk to prevent building collapse never seemed quite right to me. It seemed to make more sense to get beside a desk or preferably some other more crush resistant object. Most school desks don't look to me like they'd be able to stop a falling roof by themselves. And even if they could themselves or collectively, it seems like being beside them would be almost as good as being under. On the other hand if you're under the desk and its legs give out, then the roof is going to press down on your desk and the desk in turn will squish you. Better to be beside the desk because the roof won't be able to crush the desk totally flat, thus there will be a small space next to the desk where the ceiling wont reach all the way to the floor.
I think the school desk manufacturers are starting to advertise their school desks as more resistant to the crushing forces of black holes in addition to nuclear blasts. School district procurement officers have called for a budget increase to pay for the stronger desks, because if it saves just one child's life... However, most engineers are skeptical of these marketing claims.
Elon Musk's brother Kimbal has a page with a little info here http://kwajrockets.blogspot.com/
There is some discussion here http://spacefellowship.com/Forum/about5898.html
Spacefellowship.com also has a discussion area for Armadillo Aerospace where actual members of the team and even John Carmack sometimes respond to posts.
Where else do people go to discuss SpaceX?
Please join me in begging SpaceX to seed a torrent of their broadcast quality video of the launch. Mod me up to +5 so someone there will be more likely to see this plea.
>Why make a relatively paltry living as a scientist when you can make oodles of cash as a lawyer, running a business, or even to a lesser degree, writing software?
Because for some geeks prestige and riches aren't their first priority. Some are more interested in doing something fun or important. Why give up much of your life to money making activities when you can get enough money doing what you love?
I'm surprised nobody has mentioned yet that http://spacex.com/ is building a reusable manned launch vehicle right now. SpaceX already has a contract with NASA but I don't know for what. They're waiting for the Fourth of July vacation to end to launch their Falcon 1 rocket at the end of this month. Their launch manifest lists the first launch of their Falcon 9 before the end of the year.
There seems to be little appreciation of the importance of SpaceX's projects. Their Falcon 1 is supposed to have a reusable first stage and their Falcon 9 is supposed to have both a reusable first and second stage. If SpaceX can get these rockets to work they could be the huge breakthrough in launch costs that we've been waiting for. The Falcon 9 hasn't flown yet and the Falcon 1 has flown and crashed twice, but it almost got to orbit. I don't see how any other launch vehicle in the world will be able to compete with SpaceX if they can reuse their rockets. Although I guess if the Space Shuttle could mess up the economics of reuseability then maybe SpaceX can to.
>>it is good to have a sysadmin who can write programs in binary
>I'd like to meet one of these sysadmins.
My first digital electronics project was an attempt to program a PIC16F84 microcontroller. Unfortunately none of the three programmers or software that I built from downloaded schematics would work. I couldn't afford a pre-built programmer so I had to design my own. My programmer had an LED on the programming pin so I could verify every bit going in. My software was a QBasic program that pulsed a parallel port pin with each key press. I sent the entire binary programming sequence specified in the datasheet to the microcontroller bit by bit. It still didn't work. In a desperate attempt to get it to work I finally tried programming it at the low end of the specified voltage range (3V) instead of at the standard 5V. I finally determined that for some reason it wouldn't program if the supply voltage was above about 4.5V. Many months later I ordered another batch of PIC16F84s from DigiKey and to spite my careful anti-static handling they also wouldn't program above 4.5V. Admittedly the first thing I did after getting that LED flashing test program to work was to modify my programmer software to take the PIC assembler hex output instead of me having to hand compile and input the binary bit by bit.
The trick to guessing how many jelly beans or whatever are in a jar is to estimate how many beans tall wide and long the jar is and then multiply it out as if the jar was rectangular. You can then take off a little bit to adjust for a round rather than rectangular jar, but your estimate will be so inaccurate anyway that a little bit like that won't matter much anyway. You'll still be way off, but much closer than anyone that just looks at it and makes a guess.
If the items in the container are very small like grains of sand, then it may help to first estimate the width of a group of the items and then estimate how many groups wide the container is. For example it might take three grains of sand to make a millimeter and therefore 30 grains of sand to a centimeter. If a barrel is 60 centimeters wide then the barrel is about 1800 grains of sand wide. Round that off to 2000. A cube 2000 grains across would have about 2000*2000*2000 = 8,000,000,000 grains of sand.
The thing that makes estimating volumes so hard is that when the estimate of the width is cubed the error in the estimate of the width is also cubed. For example if you estimate a cube is four centimeters on a side and it is really five centimeters on a side then it will be DOUBLE the volume of your estimate.
I agree that unless the files are extremely huge or extremely numerous then storage space probably shouldn't be a concern because its cheap compared to your time and getting cheaper. But if storage space is a concern then you might look into the tiff format used by the patent office. Apparently it uses a form of lossless compression taken from fax machines and gets much better compression than many other common formats on black and white(no greyscale) documents. If it's the patent office's standard archive format then it will probably be supported for a long time. Pdf can probably use the same compression as well though. I was going to mod up someone below http://ask.slashdot.org/comments.pl?sid=593693&no_d2=1&cid=23920133 who recommended PDF/A as the only archive format to use.
I was also going to mod up someone who recommended http://ask.slashdot.org/comments.pl?sid=593693&no_d2=1&cid=23921141 that if you use tiff just make sure it can be read by libtiff and you should have no worries about future readability.
I still don't think it will be long after we have computers of sufficient power that we will be able to create strong AI. Trying to create AI with the computers we have now would be like trying to rewire a mouse brain to be as smart as Einstein. You just can't do it a thousand times slower if you don't have the hardware to work with. It may be hard to develop the algorithms if you don't have the hardware to test on, or we may already have pretty much all the algorithms we need but just don't have the hardware to put them together on a large enough scale. The biggest computers of 2008 might barely be enough but they're not optimized for AI and not much of their time is likely to be spent on AI.
The most common counter argument to the above is that we haven't even matched the intelligence of insects or dogs. But actually I think we can match the intelligence of insects. We don't make good insect replicas mainly for lack of mechanical miniaturization technology. Furthermore there probably aren't very many talented researchers trying to replicate useless insect behavior. As for dogs, the machines most AI researchers use probably don't even have the computational power of a dog brain.
>What do the Swiss have to do with it?
Oops, I guess it's Sweden not Switzerland.
>The NSA can probably get VeriSign to sign anything they want.
Maybe they can. Or they could just start their own Certificate Authority and get themselves onto the list of trusted authorities that comes installed with browsers or mail software.
But either way they might be reluctant to do the MITM like that because the bogus certificate with the genuine signature could be recorded by the targets and released to the public, causing great embarrassment to the certificate authority and much degradation to the trust of the certificate system.
let me repeat my last post with better formatting.
>We have used a self signed certificate for years and hundreds of other MTAs connect to us and happily set up a encrypted session to transfer mail.
If the other Mail Transfer Agents are accepting your self signed certificate without verification, then the Swiss can just generate their own certificate and pull a man in the middle attack on any of your traffic that goes through them.
>We have used a self signed certificate for years and hundreds of other MTAs connect to us and happily set up a encrypted session to transfer mail. If the other Mail Transfer Agents are accepting your self signed certificate without verification, then the Swiss can just generate their own certificate and pull a man in the middle attack on any of your traffic that goes through them.
>The GPL effectively restricts your freedom to sell installs at a profit
Sort of like laws against slavery restrict your freedom to sell humans at a profit. The company in this case is selling hardware along with the GPL software anyway. I think there's a place for proprietary software. And I agree it makes it harder for software developers to make profits. But I think the losses to software developers are more than offset by the benefits to software consumers. It's like a machine that puts thousands of people out of work. Overall such machines end up making everyone richer. Overall I think Free Software makes everyone richer. But again, I do believe that copyright does allow a lot of valuable software to be developed that we would all have to suffer without if there was no copyright.
The GPL only restricts your freedom in a way similar to laws that prohibit slavery are restricting your freedom to take slaves. The GPL only takes away your freedom to take away the freedom of your users and the original authors of your code.
Even when adjusting for weight, the tensile strength of wood isn't so great compared to S-glass or carbon fiber. And when adjusting for cross sectional area, the tensile strength of wood fares even worse because it has a lot of air in its pores.
Icebike wrote
>...wood has the highest tensile strength of any building material known to man based either on weight or cross sectional area.
I Think your estimate of wood is much too high. Wikipedia's article of tensile strength http://en.wikipedia.org/wiki/Tensile_strength lists pine wood at 40 MPa I know there are some woods that are significantly stronger but still.
For comparison some other tensile strengths listed in MPa are:
Cast Iron 200
structural steel 400
steel piano wire 2500
Concrete 3
HDPE plastic 37
Aluminum Aloy 455
Glass 4710
Carbon fiber 5650
Carbon nanotubes 63000
I was thinking that it would be foolhardy to trust that some discovery in quantum physics would not render quantum cryptography insecure. But then I realized two things. First, you can always just use QC to wrap conventional cryptography so you get the security of both. Second, conventional cryptography can be eavesdropped on and recorded to be broken someday when weaknesses or more computational power is available. With QC your communications can't even be recorded for future breaking until some new physics comes along.
The main reason was that there was no need to develop any new technology. It was only necessary for previously developed tech to be implemented cheaply. Any great NEW technology like efficient light bulbs or a cancer cure or whatever will usually have such a huge payoff to its developer that a few extra million isn't likely to add much extra incentive. If funders think it can be done then they'll fund it even without the prize. If those who would fund it see it as a long shot then the prize won't change the equation much.
The other reason the X-Prize was successful was that it wasn't clear that a manned suborbital rocket could be profitable. Boeing or Lockheed could have easily built such a rocket. If they thought it would be profitable then why wouldn't they? Maybe they thought that anything less than a very careful and therefore prohibitively expensive development project would have left their deep pockets open to excessive liability. Again, concerns like this are not a problem for a lighting technology or a cancer cure or an efficient car technology.
Oh well, best of luck anyway. Even if these prizes are a waste at least they aren't wasting all that much in the grand scheme of things.
What do you mean? Are parachutes not fragile or not expensive or are they cheap to rent or do they have much better used value than I think or what? The first link from a Google search for parachute is the parachuteshop.com which lists new setups at about $4000 and a used main canopy at $1200. That leaves plenty of room for reducing cost. I'd estimate that a chute with 1/4 the area could be made of fabric four times thicker and still come in a fraction of the cost of a land chute. If touching down in a large water area you could probably dispense with the parafoil design and just go with a simple round design as well.
It occurred to me couple years ago that one of the things that makes skydiving a little expensive is the parachute. To slow a person down enough to touch down on land means the chute has to be quite large and thus quite fragile in order to be packed down small enough. Fragile chutes wear out quicker as well. So why not touch down on water instead? You could tolerate a much higher touchdown speed and thus you could use a much smaller parachute. The chute could be made thicker and sturdier and still be packed down into an acceptable size. It could be reused many more times and would retain a higher percentage of its original price when sold used. Rentals would probably be safer, cheaper, more profitable, and more popular. Also, broken legs and crashes into trees and power lines would probably be reduced. Though perhaps drownings would be unacceptably common. Getting into the sport would be much cheaper, with the airplane ride becoming the dominant cost for the first jump. Or maybe I misunderstand the economics of skydiving as it is. Have you heard of this idea before? Does it sound like a good idea?
Add a small removable hydrocarbon fuelled generator to an electric car with just enough battery capacity for your daily commute and you have a great system. Emission free and chargeable by various clean technologies for your daily commute but with extended range for occasional trips. Generators are cheap and if you leave it behind on a daily basis your car is lighter. You can power extended trips with biodiesel or ethanol. I don't see how electric will work very well for long haul trucks though.
Is this what your post seems to imply - a book about how to use unix that comes with software which only runs on windows? WTF - Who is the publisher? Microsoft Press?